drivers/tty/serial/imx.c

   1 /*
   2  * Driver for Motorola/Freescale IMX serial ports
   3  *
   4  * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
   5  *
   6  * Author: Sascha Hauer <sascha@saschahauer.de>
   7  * Copyright (C) 2004 Pengutronix
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  */
  19
  20 #if defined(CONFIG_SERIAL_IMX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
  21 #define SUPPORT_SYSRQ
  22 #endif
  23
  24 #include <linux/module.h>
  25 #include <linux/ioport.h>
  26 #include <linux/init.h>
  27 #include <linux/console.h>
  28 #include <linux/sysrq.h>
  29 #include <linux/platform_device.h>
  30 #include <linux/tty.h>
  31 #include <linux/tty_flip.h>
  32 #include <linux/serial_core.h>
  33 #include <linux/serial.h>
  34 #include <linux/clk.h>
  35 #include <linux/delay.h>
  36 #include <linux/rational.h>
  37 #include <linux/slab.h>
  38 #include <linux/of.h>
  39 #include <linux/of_device.h>
  40 #include <linux/io.h>
  41 #include <linux/dma-mapping.h>
  42
  43 #include <asm/irq.h>
  44 #include <linux/platform_data/serial-imx.h>
  45 #include <linux/platform_data/dma-imx.h>
  46
  47 #include "serial_mctrl_gpio.h"
  48
  49 /* Register definitions */
  50 #define URXD0 0x0  /* Receiver Register */
  51 #define URTX0 0x40 /* Transmitter Register */
  52 #define UCR1  0x80 /* Control Register 1 */
  53 #define UCR2  0x84 /* Control Register 2 */
  54 #define UCR3  0x88 /* Control Register 3 */
  55 #define UCR4  0x8c /* Control Register 4 */
  56 #define UFCR  0x90 /* FIFO Control Register */
  57 #define USR1  0x94 /* Status Register 1 */
  58 #define USR2  0x98 /* Status Register 2 */
  59 #define UESC  0x9c /* Escape Character Register */
  60 #define UTIM  0xa0 /* Escape Timer Register */
  61 #define UBIR  0xa4 /* BRM Incremental Register */
  62 #define UBMR  0xa8 /* BRM Modulator Register */
  63 #define UBRC  0xac /* Baud Rate Count Register */
  64 #define IMX21_ONEMS 0xb0 /* One Millisecond register */
  65 #define IMX1_UTS 0xd0 /* UART Test Register on i.mx1 */
  66 #define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
  67
  68 /* UART Control Register Bit Fields.*/
  69 #define URXD_DUMMY_READ (1<<16)
  70 #define URXD_CHARRDY    (1<<15)
  71 #define URXD_ERR        (1<<14)
  72 #define URXD_OVRRUN     (1<<13)
  73 #define URXD_FRMERR     (1<<12)
  74 #define URXD_BRK        (1<<11)
  75 #define URXD_PRERR      (1<<10)
  76 #define URXD_RX_DATA    (0xFF<<0)
  77 #define UCR1_ADEN       (1<<15) /* Auto detect interrupt */
  78 #define UCR1_ADBR       (1<<14) /* Auto detect baud rate */
  79 #define UCR1_TRDYEN     (1<<13) /* Transmitter ready interrupt enable */
  80 #define UCR1_IDEN       (1<<12) /* Idle condition interrupt */
  81 #define UCR1_ICD_REG(x) (((x) & 3) << 10) /* idle condition detect */
  82 #define UCR1_RRDYEN     (1<<9)  /* Recv ready interrupt enable */
  83 #define UCR1_RDMAEN     (1<<8)  /* Recv ready DMA enable */
  84 #define UCR1_IREN       (1<<7)  /* Infrared interface enable */
  85 #define UCR1_TXMPTYEN   (1<<6)  /* Transimitter empty interrupt enable */
  86 #define UCR1_RTSDEN     (1<<5)  /* RTS delta interrupt enable */
  87 #define UCR1_SNDBRK     (1<<4)  /* Send break */
  88 #define UCR1_TDMAEN     (1<<3)  /* Transmitter ready DMA enable */
  89 #define IMX1_UCR1_UARTCLKEN (1<<2) /* UART clock enabled, i.mx1 only */
  90 #define UCR1_ATDMAEN    (1<<2)  /* Aging DMA Timer Enable */
  91 #define UCR1_DOZE       (1<<1)  /* Doze */
  92 #define UCR1_UARTEN     (1<<0)  /* UART enabled */
  93 #define UCR2_ESCI       (1<<15) /* Escape seq interrupt enable */
  94 #define UCR2_IRTS       (1<<14) /* Ignore RTS pin */
  95 #define UCR2_CTSC       (1<<13) /* CTS pin control */
  96 #define UCR2_CTS        (1<<12) /* Clear to send */
  97 #define UCR2_ESCEN      (1<<11) /* Escape enable */
  98 #define UCR2_PREN       (1<<8)  /* Parity enable */
  99 #define UCR2_PROE       (1<<7)  /* Parity odd/even */
 100 #define UCR2_STPB       (1<<6)  /* Stop */
 101 #define UCR2_WS         (1<<5)  /* Word size */
 102 #define UCR2_RTSEN      (1<<4)  /* Request to send interrupt enable */
 103 #define UCR2_ATEN       (1<<3)  /* Aging Timer Enable */
 104 #define UCR2_TXEN       (1<<2)  /* Transmitter enabled */
 105 #define UCR2_RXEN       (1<<1)  /* Receiver enabled */
 106 #define UCR2_SRST       (1<<0)  /* SW reset */
 107 #define UCR3_DTREN      (1<<13) /* DTR interrupt enable */
 108 #define UCR3_PARERREN   (1<<12) /* Parity enable */
 109 #define UCR3_FRAERREN   (1<<11) /* Frame error interrupt enable */
 110 #define UCR3_DSR        (1<<10) /* Data set ready */
 111 #define UCR3_DCD        (1<<9)  /* Data carrier detect */
 112 #define UCR3_RI         (1<<8)  /* Ring indicator */
 113 #define UCR3_ADNIMP     (1<<7)  /* Autobaud Detection Not Improved */
 114 #define UCR3_RXDSEN     (1<<6)  /* Receive status interrupt enable */
 115 #define UCR3_AIRINTEN   (1<<5)  /* Async IR wake interrupt enable */
 116 #define UCR3_AWAKEN     (1<<4)  /* Async wake interrupt enable */
 117 #define UCR3_DTRDEN     (1<<3)  /* Data Terminal Ready Delta Enable. */
 118 #define IMX21_UCR3_RXDMUXSEL    (1<<2)  /* RXD Muxed Input Select */
 119 #define UCR3_INVT       (1<<1)  /* Inverted Infrared transmission */
 120 #define UCR3_BPEN       (1<<0)  /* Preset registers enable */
 121 #define UCR4_CTSTL_SHF  10      /* CTS trigger level shift */
 122 #define UCR4_CTSTL_MASK 0x3F    /* CTS trigger is 6 bits wide */
 123 #define UCR4_INVR       (1<<9)  /* Inverted infrared reception */
 124 #define UCR4_ENIRI      (1<<8)  /* Serial infrared interrupt enable */
 125 #define UCR4_WKEN       (1<<7)  /* Wake interrupt enable */
 126 #define UCR4_REF16      (1<<6)  /* Ref freq 16 MHz */
 127 #define UCR4_IDDMAEN    (1<<6)  /* DMA IDLE Condition Detected */
 128 #define UCR4_IRSC       (1<<5)  /* IR special case */
 129 #define UCR4_TCEN       (1<<3)  /* Transmit complete interrupt enable */
 130 #define UCR4_BKEN       (1<<2)  /* Break condition interrupt enable */
 131 #define UCR4_OREN       (1<<1)  /* Receiver overrun interrupt enable */
 132 #define UCR4_DREN       (1<<0)  /* Recv data ready interrupt enable */
 133 #define UFCR_RXTL_SHF   0       /* Receiver trigger level shift */
 134 #define UFCR_DCEDTE     (1<<6)  /* DCE/DTE mode select */
 135 #define UFCR_RFDIV      (7<<7)  /* Reference freq divider mask */
 136 #define UFCR_RFDIV_REG(x)       (((x) < 7 ? 6 - (x) : 6) << 7)
 137 #define UFCR_TXTL_SHF   10      /* Transmitter trigger level shift */
 138 #define USR1_PARITYERR  (1<<15) /* Parity error interrupt flag */
 139 #define USR1_RTSS       (1<<14) /* RTS pin status */
 140 #define USR1_TRDY       (1<<13) /* Transmitter ready interrupt/dma flag */
 141 #define USR1_RTSD       (1<<12) /* RTS delta */
 142 #define USR1_ESCF       (1<<11) /* Escape seq interrupt flag */
 143 #define USR1_FRAMERR    (1<<10) /* Frame error interrupt flag */
 144 #define USR1_RRDY       (1<<9)   /* Receiver ready interrupt/dma flag */
 145 #define USR1_AGTIM      (1<<8)   /* Ageing timer interrupt flag */
 146 #define USR1_DTRD       (1<<7)   /* DTR Delta */
 147 #define USR1_RXDS        (1<<6)  /* Receiver idle interrupt flag */
 148 #define USR1_AIRINT      (1<<5)  /* Async IR wake interrupt flag */
 149 #define USR1_AWAKE       (1<<4)  /* Aysnc wake interrupt flag */
 150 #define USR2_ADET        (1<<15) /* Auto baud rate detect complete */
 151 #define USR2_TXFE        (1<<14) /* Transmit buffer FIFO empty */
 152 #define USR2_DTRF        (1<<13) /* DTR edge interrupt flag */
 153 #define USR2_IDLE        (1<<12) /* Idle condition */
 154 #define USR2_RIDELT      (1<<10) /* Ring Interrupt Delta */
 155 #define USR2_RIIN        (1<<9)  /* Ring Indicator Input */
 156 #define USR2_IRINT       (1<<8)  /* Serial infrared interrupt flag */
 157 #define USR2_WAKE        (1<<7)  /* Wake */
 158 #define USR2_DCDIN       (1<<5)  /* Data Carrier Detect Input */
 159 #define USR2_RTSF        (1<<4)  /* RTS edge interrupt flag */
 160 #define USR2_TXDC        (1<<3)  /* Transmitter complete */
 161 #define USR2_BRCD        (1<<2)  /* Break condition */
 162 #define USR2_ORE        (1<<1)   /* Overrun error */
 163 #define USR2_RDR        (1<<0)   /* Recv data ready */
 164 #define UTS_FRCPERR     (1<<13) /* Force parity error */
 165 #define UTS_LOOP        (1<<12)  /* Loop tx and rx */
 166 #define UTS_TXEMPTY      (1<<6)  /* TxFIFO empty */
 167 #define UTS_RXEMPTY      (1<<5)  /* RxFIFO empty */
 168 #define UTS_TXFULL       (1<<4)  /* TxFIFO full */
 169 #define UTS_RXFULL       (1<<3)  /* RxFIFO full */
 170 #define UTS_SOFTRST      (1<<0)  /* Software reset */
 171
 172 /* We've been assigned a range on the "Low-density serial ports" major */
 173 #define SERIAL_IMX_MAJOR        207
 174 #define MINOR_START             16
 175 #define DEV_NAME                "ttymxc"
 176
 177 /*
 178  * This determines how often we check the modem status signals
 179  * for any change.  They generally aren't connected to an IRQ
 180  * so we have to poll them.  We also check immediately before
 181  * filling the TX fifo incase CTS has been dropped.
 182  */
 183 #define MCTRL_TIMEOUT   (250*HZ/1000)
 184
 185 #define DRIVER_NAME "IMX-uart"
 186
 187 #define UART_NR 8
 188
 189 /* i.MX21 type uart runs on all i.mx except i.MX1 and i.MX6q */
 190 enum imx_uart_type {
 191         IMX1_UART,
 192         IMX21_UART,
 193         IMX53_UART,
 194         IMX6Q_UART,
 195 };
 196
 197 /* device type dependent stuff */
 198 struct imx_uart_data {
 199         unsigned uts_reg;
 200         enum imx_uart_type devtype;
 201 };
 202
 203 struct imx_port {
 204         struct uart_port        port;
 205         struct timer_list       timer;
 206         unsigned int            old_status;
 207         unsigned int            have_rtscts:1;
 208         unsigned int            dte_mode:1;
 209         unsigned int            irda_inv_rx:1;
 210         unsigned int            irda_inv_tx:1;
 211         unsigned short          trcv_delay; /* transceiver delay */
 212         struct clk              *clk_ipg;
 213         struct clk              *clk_per;
 214         const struct imx_uart_data *devdata;
 215
 216         struct mctrl_gpios *gpios;
 217
 218         /* DMA fields */
 219         unsigned int            dma_is_inited:1;
 220         unsigned int            dma_is_enabled:1;
 221         unsigned int            dma_is_rxing:1;
 222         unsigned int            dma_is_txing:1;
 223         struct dma_chan         *dma_chan_rx, *dma_chan_tx;
 224         struct scatterlist      rx_sgl, tx_sgl[2];
 225         void                    *rx_buf;
 226         struct circ_buf         rx_ring;
 227         unsigned int            rx_periods;
 228         dma_cookie_t            rx_cookie;
 229         unsigned int            tx_bytes;
 230         unsigned int            dma_tx_nents;
 231         wait_queue_head_t       dma_wait;
 232         unsigned int            saved_reg[10];
 233         bool                    context_saved;
 234 };
 235
 236 struct imx_port_ucrs {
 237         unsigned int    ucr1;
 238         unsigned int    ucr2;
 239         unsigned int    ucr3;
 240 };
 241
 242 static struct imx_uart_data imx_uart_devdata[] = {
 243         [IMX1_UART] = {
 244                 .uts_reg = IMX1_UTS,
 245                 .devtype = IMX1_UART,
 246         },
 247         [IMX21_UART] = {
 248                 .uts_reg = IMX21_UTS,
 249                 .devtype = IMX21_UART,
 250         },
 251         [IMX53_UART] = {
 252                 .uts_reg = IMX21_UTS,
 253                 .devtype = IMX53_UART,
 254         },
 255         [IMX6Q_UART] = {
 256                 .uts_reg = IMX21_UTS,
 257                 .devtype = IMX6Q_UART,
 258         },
 259 };
 260
 261 static const struct platform_device_id imx_uart_devtype[] = {
 262         {
 263                 .name = "imx1-uart",
 264                 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX1_UART],
 265         }, {
 266                 .name = "imx21-uart",
 267                 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX21_UART],
 268         }, {
 269                 .name = "imx53-uart",
 270                 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX53_UART],
 271         }, {
 272                 .name = "imx6q-uart",
 273                 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX6Q_UART],
 274         }, {
 275                 /* sentinel */
 276         }
 277 };
 278 MODULE_DEVICE_TABLE(platform, imx_uart_devtype);
 279
 280 static const struct of_device_id imx_uart_dt_ids[] = {
 281         { .compatible = "fsl,imx6q-uart", .data = &imx_uart_devdata[IMX6Q_UART], },
 282         { .compatible = "fsl,imx53-uart", .data = &imx_uart_devdata[IMX53_UART], },
 283         { .compatible = "fsl,imx1-uart", .data = &imx_uart_devdata[IMX1_UART], },
 284         { .compatible = "fsl,imx21-uart", .data = &imx_uart_devdata[IMX21_UART], },
 285         { /* sentinel */ }
 286 };
 287 MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
 288
 289 static inline unsigned uts_reg(struct imx_port *sport)
 290 {
 291         return sport->devdata->uts_reg;
 292 }
 293
 294 static inline int is_imx1_uart(struct imx_port *sport)
 295 {
 296         return sport->devdata->devtype == IMX1_UART;
 297 }
 298
 299 static inline int is_imx21_uart(struct imx_port *sport)
 300 {
 301         return sport->devdata->devtype == IMX21_UART;
 302 }
 303
 304 static inline int is_imx53_uart(struct imx_port *sport)
 305 {
 306         return sport->devdata->devtype == IMX53_UART;
 307 }
 308
 309 static inline int is_imx6q_uart(struct imx_port *sport)
 310 {
 311         return sport->devdata->devtype == IMX6Q_UART;
 312 }
 313 /*
 314  * Save and restore functions for UCR1, UCR2 and UCR3 registers
 315  */
 316 #if defined(CONFIG_SERIAL_IMX_CONSOLE)
 317 static void imx_port_ucrs_save(struct uart_port *port,
 318                                struct imx_port_ucrs *ucr)
 319 {
 320         /* save control registers */
 321         ucr->ucr1 = readl(port->membase + UCR1);
 322         ucr->ucr2 = readl(port->membase + UCR2);
 323         ucr->ucr3 = readl(port->membase + UCR3);
 324 }
 325
 326 static void imx_port_ucrs_restore(struct uart_port *port,
 327                                   struct imx_port_ucrs *ucr)
 328 {
 329         /* restore control registers */
 330         writel(ucr->ucr1, port->membase + UCR1);
 331         writel(ucr->ucr2, port->membase + UCR2);
 332         writel(ucr->ucr3, port->membase + UCR3);
 333 }
 334 #endif
 335
 336 static void imx_port_rts_active(struct imx_port *sport, unsigned long *ucr2)
 337 {
 338         *ucr2 &= ~UCR2_CTSC;
 339         *ucr2 |= UCR2_CTS;
 340
 341         mctrl_gpio_set(sport->gpios, sport->port.mctrl | TIOCM_RTS);
 342 }
 343
 344 static void imx_port_rts_inactive(struct imx_port *sport, unsigned long *ucr2)
 345 {
 346         *ucr2 &= ~(UCR2_CTSC | UCR2_CTS);
 347
 348         mctrl_gpio_set(sport->gpios, sport->port.mctrl & ~TIOCM_RTS);
 349 }
 350
 351 static void imx_port_rts_auto(struct imx_port *sport, unsigned long *ucr2)
 352 {
 353         *ucr2 |= UCR2_CTSC;
 354 }
 355
 356 /*
 357  * interrupts disabled on entry
 358  */
 359 static void imx_stop_tx(struct uart_port *port)
 360 {
 361         struct imx_port *sport = (struct imx_port *)port;
 362         unsigned long temp;
 363
 364         /*
 365          * We are maybe in the SMP context, so if the DMA TX thread is running
 366          * on other cpu, we have to wait for it to finish.
 367          */
 368         if (sport->dma_is_enabled && sport->dma_is_txing)
 369                 return;
 370
 371         temp = readl(port->membase + UCR1);
 372         writel(temp & ~UCR1_TXMPTYEN, port->membase + UCR1);
 373
 374         /* in rs485 mode disable transmitter if shifter is empty */
 375         if (port->rs485.flags & SER_RS485_ENABLED &&
 376             readl(port->membase + USR2) & USR2_TXDC) {
 377                 temp = readl(port->membase + UCR2);
 378                 if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
 379                         imx_port_rts_inactive(sport, &temp);
 380                 else
 381                         imx_port_rts_active(sport, &temp);
 382                 temp |= UCR2_RXEN;
 383                 writel(temp, port->membase + UCR2);
 384
 385                 temp = readl(port->membase + UCR4);
 386                 temp &= ~UCR4_TCEN;
 387                 writel(temp, port->membase + UCR4);
 388         }
 389 }
 390
 391 /*
 392  * interrupts disabled on entry
 393  */
 394 static void imx_stop_rx(struct uart_port *port)
 395 {
 396         struct imx_port *sport = (struct imx_port *)port;
 397         unsigned long temp;
 398
 399         if (sport->dma_is_enabled && sport->dma_is_rxing) {
 400                 if (sport->port.suspended) {
 401                         dmaengine_terminate_all(sport->dma_chan_rx);
 402                         sport->dma_is_rxing = 0;
 403                 } else {
 404                         return;
 405                 }
 406         }
 407
 408         temp = readl(sport->port.membase + UCR2);
 409         writel(temp & ~UCR2_RXEN, sport->port.membase + UCR2);
 410
 411         /* disable the `Receiver Ready Interrrupt` */
 412         temp = readl(sport->port.membase + UCR1);
 413         writel(temp & ~UCR1_RRDYEN, sport->port.membase + UCR1);
 414 }
 415
 416 /*
 417  * Set the modem control timer to fire immediately.
 418  */
 419 static void imx_enable_ms(struct uart_port *port)
 420 {
 421         struct imx_port *sport = (struct imx_port *)port;
 422
 423         mod_timer(&sport->timer, jiffies);
 424
 425         mctrl_gpio_enable_ms(sport->gpios);
 426 }
 427
 428 static void imx_dma_tx(struct imx_port *sport);
 429 static inline void imx_transmit_buffer(struct imx_port *sport)
 430 {
 431         struct circ_buf *xmit = &sport->port.state->xmit;
 432         unsigned long temp;
 433
 434         if (sport->port.x_char) {
 435                 /* Send next char */
 436                 writel(sport->port.x_char, sport->port.membase + URTX0);
 437                 sport->port.icount.tx++;
 438                 sport->port.x_char = 0;
 439                 return;
 440         }
 441
 442         if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
 443                 imx_stop_tx(&sport->port);
 444                 return;
 445         }
 446
 447         if (sport->dma_is_enabled) {
 448                 /*
 449                  * We've just sent a X-char Ensure the TX DMA is enabled
 450                  * and the TX IRQ is disabled.
 451                  **/
 452                 temp = readl(sport->port.membase + UCR1);
 453                 temp &= ~UCR1_TXMPTYEN;
 454                 if (sport->dma_is_txing) {
 455                         temp |= UCR1_TDMAEN;
 456                         writel(temp, sport->port.membase + UCR1);
 457                 } else {
 458                         writel(temp, sport->port.membase + UCR1);
 459                         imx_dma_tx(sport);
 460                 }
 461         }
 462
 463         while (!uart_circ_empty(xmit) &&
 464                !(readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)) {
 465                 /* send xmit->buf[xmit->tail]
 466                  * out the port here */
 467                 writel(xmit->buf[xmit->tail], sport->port.membase + URTX0);
 468                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 469                 sport->port.icount.tx++;
 470         }
 471
 472         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 473                 uart_write_wakeup(&sport->port);
 474
 475         if (uart_circ_empty(xmit))
 476                 imx_stop_tx(&sport->port);
 477 }
 478
 479 static void dma_tx_callback(void *data)
 480 {
 481         struct imx_port *sport = data;
 482         struct scatterlist *sgl = &sport->tx_sgl[0];
 483         struct circ_buf *xmit = &sport->port.state->xmit;
 484         unsigned long flags;
 485         unsigned long temp;
 486
 487         spin_lock_irqsave(&sport->port.lock, flags);
 488
 489         dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
 490
 491         temp = readl(sport->port.membase + UCR1);
 492         temp &= ~UCR1_TDMAEN;
 493         writel(temp, sport->port.membase + UCR1);
 494
 495         /* update the stat */
 496         xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1);
 497         sport->port.icount.tx += sport->tx_bytes;
 498
 499         dev_dbg(sport->port.dev, "we finish the TX DMA.\n");
 500
 501         sport->dma_is_txing = 0;
 502
 503         spin_unlock_irqrestore(&sport->port.lock, flags);
 504
 505         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 506                 uart_write_wakeup(&sport->port);
 507
 508         if (waitqueue_active(&sport->dma_wait)) {
 509                 wake_up(&sport->dma_wait);
 510                 dev_dbg(sport->port.dev, "exit in %s.\n", __func__);
 511                 return;
 512         }
 513
 514         spin_lock_irqsave(&sport->port.lock, flags);
 515         if (!uart_circ_empty(xmit) && !uart_tx_stopped(&sport->port))
 516                 imx_dma_tx(sport);
 517         spin_unlock_irqrestore(&sport->port.lock, flags);
 518 }
 519
 520 static void imx_dma_tx(struct imx_port *sport)
 521 {
 522         struct circ_buf *xmit = &sport->port.state->xmit;
 523         struct scatterlist *sgl = sport->tx_sgl;
 524         struct dma_async_tx_descriptor *desc;
 525         struct dma_chan *chan = sport->dma_chan_tx;
 526         struct device *dev = sport->port.dev;
 527         unsigned long temp;
 528         int ret;
 529
 530         if (sport->dma_is_txing)
 531                 return;
 532
 533         sport->tx_bytes = uart_circ_chars_pending(xmit);
 534
 535         if (xmit->tail < xmit->head) {
 536                 sport->dma_tx_nents = 1;
 537                 sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
 538         } else {
 539                 sport->dma_tx_nents = 2;
 540                 sg_init_table(sgl, 2);
 541                 sg_set_buf(sgl, xmit->buf + xmit->tail,
 542                                 UART_XMIT_SIZE - xmit->tail);
 543                 sg_set_buf(sgl + 1, xmit->buf, xmit->head);
 544         }
 545
 546         ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
 547         if (ret == 0) {
 548                 dev_err(dev, "DMA mapping error for TX.\n");
 549                 return;
 550         }
 551         desc = dmaengine_prep_slave_sg(chan, sgl, sport->dma_tx_nents,
 552                                         DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
 553         if (!desc) {
 554                 dma_unmap_sg(dev, sgl, sport->dma_tx_nents,
 555                              DMA_TO_DEVICE);
 556                 dev_err(dev, "We cannot prepare for the TX slave dma!\n");
 557                 return;
 558         }
 559         desc->callback = dma_tx_callback;
 560         desc->callback_param = sport;
 561
 562         dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n",
 563                         uart_circ_chars_pending(xmit));
 564
 565         temp = readl(sport->port.membase + UCR1);
 566         temp |= UCR1_TDMAEN;
 567         writel(temp, sport->port.membase + UCR1);
 568
 569         /* fire it */
 570         sport->dma_is_txing = 1;
 571         dmaengine_submit(desc);
 572         dma_async_issue_pending(chan);
 573         return;
 574 }
 575
 576 /*
 577  * interrupts disabled on entry
 578  */
 579 static void imx_start_tx(struct uart_port *port)
 580 {
 581         struct imx_port *sport = (struct imx_port *)port;
 582         unsigned long temp;
 583
 584         if (port->rs485.flags & SER_RS485_ENABLED) {
 585                 temp = readl(port->membase + UCR2);
 586                 if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
 587                         imx_port_rts_inactive(sport, &temp);
 588                 else
 589                         imx_port_rts_active(sport, &temp);
 590                 if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
 591                         temp &= ~UCR2_RXEN;
 592                 writel(temp, port->membase + UCR2);
 593
 594                 /* enable transmitter and shifter empty irq */
 595                 temp = readl(port->membase + UCR4);
 596                 temp |= UCR4_TCEN;
 597                 writel(temp, port->membase + UCR4);
 598         }
 599
 600         if (!sport->dma_is_enabled) {
 601                 temp = readl(sport->port.membase + UCR1);
 602                 writel(temp | UCR1_TXMPTYEN, sport->port.membase + UCR1);
 603         }
 604
 605         if (sport->dma_is_enabled) {
 606                 if (sport->port.x_char) {
 607                         /* We have X-char to send, so enable TX IRQ and
 608                          * disable TX DMA to let TX interrupt to send X-char */
 609                         temp = readl(sport->port.membase + UCR1);
 610                         temp &= ~UCR1_TDMAEN;
 611                         temp |= UCR1_TXMPTYEN;
 612                         writel(temp, sport->port.membase + UCR1);
 613                         return;
 614                 }
 615
 616                 if (!uart_circ_empty(&port->state->xmit) &&
 617                     !uart_tx_stopped(port))
 618                         imx_dma_tx(sport);
 619                 return;
 620         }
 621 }
 622
 623 static irqreturn_t imx_rtsint(int irq, void *dev_id)
 624 {
 625         struct imx_port *sport = dev_id;
 626         unsigned int val;
 627         unsigned long flags;
 628
 629         spin_lock_irqsave(&sport->port.lock, flags);
 630
 631         writel(USR1_RTSD, sport->port.membase + USR1);
 632         val = readl(sport->port.membase + USR1) & USR1_RTSS;
 633         uart_handle_cts_change(&sport->port, !!val);
 634         wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
 635
 636         spin_unlock_irqrestore(&sport->port.lock, flags);
 637         return IRQ_HANDLED;
 638 }
 639
 640 static irqreturn_t imx_txint(int irq, void *dev_id)
 641 {
 642         struct imx_port *sport = dev_id;
 643         unsigned long flags;
 644
 645         spin_lock_irqsave(&sport->port.lock, flags);
 646         imx_transmit_buffer(sport);
 647         spin_unlock_irqrestore(&sport->port.lock, flags);
 648         return IRQ_HANDLED;
 649 }
 650
 651 static irqreturn_t imx_rxint(int irq, void *dev_id)
 652 {
 653         struct imx_port *sport = dev_id;
 654         unsigned int rx, flg, ignored = 0;
 655         struct tty_port *port = &sport->port.state->port;
 656         unsigned long flags, temp;
 657
 658         spin_lock_irqsave(&sport->port.lock, flags);
 659
 660         while (readl(sport->port.membase + USR2) & USR2_RDR) {
 661                 flg = TTY_NORMAL;
 662                 sport->port.icount.rx++;
 663
 664                 rx = readl(sport->port.membase + URXD0);
 665
 666                 temp = readl(sport->port.membase + USR2);
 667                 if (temp & USR2_BRCD) {
 668                         writel(USR2_BRCD, sport->port.membase + USR2);
 669                         if (uart_handle_break(&sport->port))
 670                                 continue;
 671                 }
 672
 673                 if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
 674                         continue;
 675
 676                 if (unlikely(rx & URXD_ERR)) {
 677                         if (rx & URXD_BRK)
 678                                 sport->port.icount.brk++;
 679                         else if (rx & URXD_PRERR)
 680                                 sport->port.icount.parity++;
 681                         else if (rx & URXD_FRMERR)
 682                                 sport->port.icount.frame++;
 683                         if (rx & URXD_OVRRUN)
 684                                 sport->port.icount.overrun++;
 685
 686                         if (rx & sport->port.ignore_status_mask) {
 687                                 if (++ignored > 100)
 688                                         goto out;
 689                                 continue;
 690                         }
 691
 692                         rx &= (sport->port.read_status_mask | 0xFF);
 693
 694                         if (rx & URXD_BRK)
 695                                 flg = TTY_BREAK;
 696                         else if (rx & URXD_PRERR)
 697                                 flg = TTY_PARITY;
 698                         else if (rx & URXD_FRMERR)
 699                                 flg = TTY_FRAME;
 700                         if (rx & URXD_OVRRUN)
 701                                 flg = TTY_OVERRUN;
 702
 703 #ifdef SUPPORT_SYSRQ
 704                         sport->port.sysrq = 0;
 705 #endif
 706                 }
 707
 708                 if (sport->port.ignore_status_mask & URXD_DUMMY_READ)
 709                         goto out;
 710
 711                 if (tty_insert_flip_char(port, rx, flg) == 0)
 712                         sport->port.icount.buf_overrun++;
 713         }
 714
 715 out:
 716         spin_unlock_irqrestore(&sport->port.lock, flags);
 717         tty_flip_buffer_push(port);
 718         return IRQ_HANDLED;
 719 }
 720
 721 static void clear_rx_errors(struct imx_port *sport);
 722 static int start_rx_dma(struct imx_port *sport);
 723 /*
 724  * If the RXFIFO is filled with some data, and then we
 725  * arise a DMA operation to receive them.
 726  */
 727 static void imx_dma_rxint(struct imx_port *sport)
 728 {
 729         unsigned long temp;
 730         unsigned long flags;
 731
 732         spin_lock_irqsave(&sport->port.lock, flags);
 733
 734         temp = readl(sport->port.membase + USR2);
 735         if ((temp & USR2_RDR) && !sport->dma_is_rxing) {
 736                 sport->dma_is_rxing = 1;
 737
 738                 /* disable the receiver ready and aging timer interrupts */
 739                 temp = readl(sport->port.membase + UCR1);
 740                 temp &= ~(UCR1_RRDYEN);
 741                 writel(temp, sport->port.membase + UCR1);
 742
 743                 temp = readl(sport->port.membase + UCR2);
 744                 temp &= ~(UCR2_ATEN);
 745                 writel(temp, sport->port.membase + UCR2);
 746
 747                 /* disable the rx errors interrupts */
 748                 temp = readl(sport->port.membase + UCR4);
 749                 temp &= ~UCR4_OREN;
 750                 writel(temp, sport->port.membase + UCR4);
 751
 752                 /* tell the DMA to receive the data. */
 753                 start_rx_dma(sport);
 754         }
 755
 756         spin_unlock_irqrestore(&sport->port.lock, flags);
 757 }
 758
 759 /*
 760  * We have a modem side uart, so the meanings of RTS and CTS are inverted.
 761  */
 762 static unsigned int imx_get_hwmctrl(struct imx_port *sport)
 763 {
 764         unsigned int tmp = TIOCM_DSR;
 765         unsigned usr1 = readl(sport->port.membase + USR1);
 766         unsigned usr2 = readl(sport->port.membase + USR2);
 767
 768         if (usr1 & USR1_RTSS)
 769                 tmp |= TIOCM_CTS;
 770
 771         /* in DCE mode DCDIN is always 0 */
 772         if (!(usr2 & USR2_DCDIN))
 773                 tmp |= TIOCM_CAR;
 774
 775         if (sport->dte_mode)
 776                 if (!(readl(sport->port.membase + USR2) & USR2_RIIN))
 777                         tmp |= TIOCM_RI;
 778
 779         return tmp;
 780 }
 781
 782 /*
 783  * Handle any change of modem status signal since we were last called.
 784  */
 785 static void imx_mctrl_check(struct imx_port *sport)
 786 {
 787         unsigned int status, changed;
 788
 789         status = imx_get_hwmctrl(sport);
 790         changed = status ^ sport->old_status;
 791
 792         if (changed == 0)
 793                 return;
 794
 795         sport->old_status = status;
 796
 797         if (changed & TIOCM_RI && status & TIOCM_RI)
 798                 sport->port.icount.rng++;
 799         if (changed & TIOCM_DSR)
 800                 sport->port.icount.dsr++;
 801         if (changed & TIOCM_CAR)
 802                 uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
 803         if (changed & TIOCM_CTS)
 804                 uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
 805
 806         wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
 807 }
 808
 809 static irqreturn_t imx_int(int irq, void *dev_id)
 810 {
 811         struct imx_port *sport = dev_id;
 812         unsigned int sts;
 813         unsigned int sts2;
 814         irqreturn_t ret = IRQ_NONE;
 815
 816         sts = readl(sport->port.membase + USR1);
 817         sts2 = readl(sport->port.membase + USR2);
 818
 819         if (sts & (USR1_RRDY | USR1_AGTIM)) {
 820                 if (sport->dma_is_enabled)
 821                         imx_dma_rxint(sport);
 822                 else
 823                         imx_rxint(irq, dev_id);
 824                 ret = IRQ_HANDLED;
 825         }
 826
 827         if ((sts & USR1_TRDY &&
 828              readl(sport->port.membase + UCR1) & UCR1_TXMPTYEN) ||
 829             (sts2 & USR2_TXDC &&
 830              readl(sport->port.membase + UCR4) & UCR4_TCEN)) {
 831                 imx_txint(irq, dev_id);
 832                 ret = IRQ_HANDLED;
 833         }
 834
 835         if (sts & USR1_DTRD) {
 836                 unsigned long flags;
 837
 838                 if (sts & USR1_DTRD)
 839                         writel(USR1_DTRD, sport->port.membase + USR1);
 840
 841                 spin_lock_irqsave(&sport->port.lock, flags);
 842                 imx_mctrl_check(sport);
 843                 spin_unlock_irqrestore(&sport->port.lock, flags);
 844
 845                 ret = IRQ_HANDLED;
 846         }
 847
 848         if (sts & USR1_RTSD) {
 849                 imx_rtsint(irq, dev_id);
 850                 ret = IRQ_HANDLED;
 851         }
 852
 853         if (sts & USR1_AWAKE) {
 854                 writel(USR1_AWAKE, sport->port.membase + USR1);
 855                 ret = IRQ_HANDLED;
 856         }
 857
 858         if (sts2 & USR2_ORE) {
 859                 sport->port.icount.overrun++;
 860                 writel(USR2_ORE, sport->port.membase + USR2);
 861                 ret = IRQ_HANDLED;
 862         }
 863
 864         return ret;
 865 }
 866
 867 /*
 868  * Return TIOCSER_TEMT when transmitter is not busy.
 869  */
 870 static unsigned int imx_tx_empty(struct uart_port *port)
 871 {
 872         struct imx_port *sport = (struct imx_port *)port;
 873         unsigned int ret;
 874
 875         ret = (readl(sport->port.membase + USR2) & USR2_TXDC) ?  TIOCSER_TEMT : 0;
 876
 877         /* If the TX DMA is working, return 0. */
 878         if (sport->dma_is_enabled && sport->dma_is_txing)
 879                 ret = 0;
 880
 881         return ret;
 882 }
 883
 884 static unsigned int imx_get_mctrl(struct uart_port *port)
 885 {
 886         struct imx_port *sport = (struct imx_port *)port;
 887         unsigned int ret = imx_get_hwmctrl(sport);
 888
 889         mctrl_gpio_get(sport->gpios, &ret);
 890
 891         return ret;
 892 }
 893
 894 static void imx_set_mctrl(struct uart_port *port, unsigned int mctrl)
 895 {
 896         struct imx_port *sport = (struct imx_port *)port;
 897         unsigned long temp;
 898
 899         if (!(port->rs485.flags & SER_RS485_ENABLED)) {
 900                 temp = readl(sport->port.membase + UCR2);
 901                 temp &= ~(UCR2_CTS | UCR2_CTSC);
 902                 if (mctrl & TIOCM_RTS)
 903                         temp |= UCR2_CTS | UCR2_CTSC;
 904                 writel(temp, sport->port.membase + UCR2);
 905         }
 906
 907         temp = readl(sport->port.membase + UCR3) & ~UCR3_DSR;
 908         if (!(mctrl & TIOCM_DTR))
 909                 temp |= UCR3_DSR;
 910         writel(temp, sport->port.membase + UCR3);
 911
 912         temp = readl(sport->port.membase + uts_reg(sport)) & ~UTS_LOOP;
 913         if (mctrl & TIOCM_LOOP)
 914                 temp |= UTS_LOOP;
 915         writel(temp, sport->port.membase + uts_reg(sport));
 916
 917         mctrl_gpio_set(sport->gpios, mctrl);
 918 }
 919
 920 /*
 921  * Interrupts always disabled.
 922  */
 923 static void imx_break_ctl(struct uart_port *port, int break_state)
 924 {
 925         struct imx_port *sport = (struct imx_port *)port;
 926         unsigned long flags, temp;
 927
 928         spin_lock_irqsave(&sport->port.lock, flags);
 929
 930         temp = readl(sport->port.membase + UCR1) & ~UCR1_SNDBRK;
 931
 932         if (break_state != 0)
 933                 temp |= UCR1_SNDBRK;
 934
 935         writel(temp, sport->port.membase + UCR1);
 936
 937         spin_unlock_irqrestore(&sport->port.lock, flags);
 938 }
 939
 940 /*
 941  * This is our per-port timeout handler, for checking the
 942  * modem status signals.
 943  */
 944 static void imx_timeout(unsigned long data)
 945 {
 946         struct imx_port *sport = (struct imx_port *)data;
 947         unsigned long flags;
 948
 949         if (sport->port.state) {
 950                 spin_lock_irqsave(&sport->port.lock, flags);
 951                 imx_mctrl_check(sport);
 952                 spin_unlock_irqrestore(&sport->port.lock, flags);
 953
 954                 mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
 955         }
 956 }
 957
 958 #define RX_BUF_SIZE     (PAGE_SIZE)
 959
 960 /*
 961  * There are two kinds of RX DMA interrupts(such as in the MX6Q):
 962  *   [1] the RX DMA buffer is full.
 963  *   [2] the aging timer expires
 964  *
 965  * Condition [2] is triggered when a character has been sitting in the FIFO
 966  * for at least 8 byte durations.
 967  */
 968 static void dma_rx_callback(void *data)
 969 {
 970         struct imx_port *sport = data;
 971         struct dma_chan *chan = sport->dma_chan_rx;
 972         struct scatterlist *sgl = &sport->rx_sgl;
 973         struct tty_port *port = &sport->port.state->port;
 974         struct dma_tx_state state;
 975         struct circ_buf *rx_ring = &sport->rx_ring;
 976         enum dma_status status;
 977         unsigned int w_bytes = 0;
 978         unsigned int r_bytes;
 979         unsigned int bd_size;
 980
 981         status = dmaengine_tx_status(chan, (dma_cookie_t)0, &state);
 982
 983         if (status == DMA_ERROR) {
 984                 dev_err(sport->port.dev, "DMA transaction error.\n");
 985                 clear_rx_errors(sport);
 986                 return;
 987         }
 988
 989         if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ)) {
 990
 991                 /*
 992                  * The state-residue variable represents the empty space
 993                  * relative to the entire buffer. Taking this in consideration
 994                  * the head is always calculated base on the buffer total
 995                  * length - DMA transaction residue. The UART script from the
 996                  * SDMA firmware will jump to the next buffer descriptor,
 997                  * once a DMA transaction if finalized (IMX53 RM - A.4.1.2.4).
 998                  * Taking this in consideration the tail is always at the
 999                  * beginning of the buffer descriptor that contains the head.
1000                  */
1001
1002                 /* Calculate the head */
1003                 rx_ring->head = sg_dma_len(sgl) - state.residue;
1004
1005                 /* Calculate the tail. */
1006                 bd_size = sg_dma_len(sgl) / sport->rx_periods;
1007                 rx_ring->tail = ((rx_ring->head-1) / bd_size) * bd_size;
1008
1009                 if (rx_ring->head <= sg_dma_len(sgl) &&
1010                     rx_ring->head > rx_ring->tail) {
1011
1012                         /* Move data from tail to head */
1013                         r_bytes = rx_ring->head - rx_ring->tail;
1014
1015                         /* CPU claims ownership of RX DMA buffer */
1016                         dma_sync_sg_for_cpu(sport->port.dev, sgl, 1,
1017                                 DMA_FROM_DEVICE);
1018
1019                         w_bytes = tty_insert_flip_string(port,
1020                                 sport->rx_buf + rx_ring->tail, r_bytes);
1021
1022                         /* UART retrieves ownership of RX DMA buffer */
1023                         dma_sync_sg_for_device(sport->port.dev, sgl, 1,
1024                                 DMA_FROM_DEVICE);
1025
1026                         if (w_bytes != r_bytes)
1027                                 sport->port.icount.buf_overrun++;
1028
1029                         sport->port.icount.rx += w_bytes;
1030                 } else  {
1031                         WARN_ON(rx_ring->head > sg_dma_len(sgl));
1032                         WARN_ON(rx_ring->head <= rx_ring->tail);
1033                 }
1034         }
1035
1036         if (w_bytes) {
1037                 tty_flip_buffer_push(port);
1038                 dev_dbg(sport->port.dev, "We get %d bytes.\n", w_bytes);
1039         }
1040 }
1041
1042 /* RX DMA buffer periods */
1043 #define RX_DMA_PERIODS 4
1044
1045 static int start_rx_dma(struct imx_port *sport)
1046 {
1047         struct scatterlist *sgl = &sport->rx_sgl;
1048         struct dma_chan *chan = sport->dma_chan_rx;
1049         struct device *dev = sport->port.dev;
1050         struct dma_async_tx_descriptor *desc;
1051         int ret;
1052
1053         sport->rx_ring.head = 0;
1054         sport->rx_ring.tail = 0;
1055         sport->rx_periods = RX_DMA_PERIODS;
1056
1057         sg_init_one(sgl, sport->rx_buf, RX_BUF_SIZE);
1058         ret = dma_map_sg(dev, sgl, 1, DMA_FROM_DEVICE);
1059         if (ret == 0) {
1060                 dev_err(dev, "DMA mapping error for RX.\n");
1061                 return -EINVAL;
1062         }
1063
1064         desc = dmaengine_prep_dma_cyclic(chan, sg_dma_address(sgl),
1065                 sg_dma_len(sgl), sg_dma_len(sgl) / sport->rx_periods,
1066                 DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
1067
1068         if (!desc) {
1069                 dma_unmap_sg(dev, sgl, 1, DMA_FROM_DEVICE);
1070                 dev_err(dev, "We cannot prepare for the RX slave dma!\n");
1071                 return -EINVAL;
1072         }
1073         desc->callback = dma_rx_callback;
1074         desc->callback_param = sport;
1075
1076         dev_dbg(dev, "RX: prepare for the DMA.\n");
1077         sport->rx_cookie = dmaengine_submit(desc);
1078         dma_async_issue_pending(chan);
1079         return 0;
1080 }
1081
1082 static void clear_rx_errors(struct imx_port *sport)
1083 {
1084         unsigned int status_usr1, status_usr2;
1085
1086         status_usr1 = readl(sport->port.membase + USR1);
1087         status_usr2 = readl(sport->port.membase + USR2);
1088
1089         if (status_usr2 & USR2_BRCD) {
1090                 sport->port.icount.brk++;
1091                 writel(USR2_BRCD, sport->port.membase + USR2);
1092         } else if (status_usr1 & USR1_FRAMERR) {
1093                 sport->port.icount.frame++;
1094                 writel(USR1_FRAMERR, sport->port.membase + USR1);
1095         } else if (status_usr1 & USR1_PARITYERR) {
1096                 sport->port.icount.parity++;
1097                 writel(USR1_PARITYERR, sport->port.membase + USR1);
1098         }
1099
1100         if (status_usr2 & USR2_ORE) {
1101                 sport->port.icount.overrun++;
1102                 writel(USR2_ORE, sport->port.membase + USR2);
1103         }
1104
1105 }
1106
1107 #define TXTL_DEFAULT 2 /* reset default */
1108 #define RXTL_DEFAULT 1 /* reset default */
1109 #define TXTL_DMA 8 /* DMA burst setting */
1110 #define RXTL_DMA 9 /* DMA burst setting */
1111
1112 static void imx_setup_ufcr(struct imx_port *sport,
1113                           unsigned char txwl, unsigned char rxwl)
1114 {
1115         unsigned int val;
1116
1117         /* set receiver / transmitter trigger level */
1118         val = readl(sport->port.membase + UFCR) & (UFCR_RFDIV | UFCR_DCEDTE);
1119         val |= txwl << UFCR_TXTL_SHF | rxwl;
1120         writel(val, sport->port.membase + UFCR);
1121 }
1122
1123 static void imx_uart_dma_exit(struct imx_port *sport)
1124 {
1125         if (sport->dma_chan_rx) {
1126                 dmaengine_terminate_sync(sport->dma_chan_rx);
1127                 dma_release_channel(sport->dma_chan_rx);
1128                 sport->dma_chan_rx = NULL;
1129                 sport->rx_cookie = -EINVAL;
1130                 kfree(sport->rx_buf);
1131                 sport->rx_buf = NULL;
1132         }
1133
1134         if (sport->dma_chan_tx) {
1135                 dmaengine_terminate_sync(sport->dma_chan_tx);
1136                 dma_release_channel(sport->dma_chan_tx);
1137                 sport->dma_chan_tx = NULL;
1138         }
1139
1140         sport->dma_is_inited = 0;
1141 }
1142
1143 static int imx_uart_dma_init(struct imx_port *sport)
1144 {
1145         struct dma_slave_config slave_config = {};
1146         struct device *dev = sport->port.dev;
1147         int ret;
1148
1149         /* Prepare for RX : */
1150         sport->dma_chan_rx = dma_request_slave_channel(dev, "rx");
1151         if (!sport->dma_chan_rx) {
1152                 dev_dbg(dev, "cannot get the DMA channel.\n");
1153                 ret = -EINVAL;
1154                 goto err;
1155         }
1156
1157         slave_config.direction = DMA_DEV_TO_MEM;
1158         slave_config.src_addr = sport->port.mapbase + URXD0;
1159         slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1160         /* one byte less than the watermark level to enable the aging timer */
1161         slave_config.src_maxburst = RXTL_DMA - 1;
1162         ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config);
1163         if (ret) {
1164                 dev_err(dev, "error in RX dma configuration.\n");
1165                 goto err;
1166         }
1167
1168         sport->rx_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
1169         if (!sport->rx_buf) {
1170                 ret = -ENOMEM;
1171                 goto err;
1172         }
1173         sport->rx_ring.buf = sport->rx_buf;
1174
1175         /* Prepare for TX : */
1176         sport->dma_chan_tx = dma_request_slave_channel(dev, "tx");
1177         if (!sport->dma_chan_tx) {
1178                 dev_err(dev, "cannot get the TX DMA channel!\n");
1179                 ret = -EINVAL;
1180                 goto err;
1181         }
1182
1183         slave_config.direction = DMA_MEM_TO_DEV;
1184         slave_config.dst_addr = sport->port.mapbase + URTX0;
1185         slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1186         slave_config.dst_maxburst = TXTL_DMA;
1187         ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config);
1188         if (ret) {
1189                 dev_err(dev, "error in TX dma configuration.");
1190                 goto err;
1191         }
1192
1193         sport->dma_is_inited = 1;
1194
1195         return 0;
1196 err:
1197         imx_uart_dma_exit(sport);
1198         return ret;
1199 }
1200
1201 static void imx_enable_dma(struct imx_port *sport)
1202 {
1203         unsigned long temp;
1204
1205         init_waitqueue_head(&sport->dma_wait);
1206
1207         /* set UCR1 */
1208         temp = readl(sport->port.membase + UCR1);
1209         temp |= UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN;
1210         writel(temp, sport->port.membase + UCR1);
1211
1212         temp = readl(sport->port.membase + UCR2);
1213         temp |= UCR2_ATEN;
1214         writel(temp, sport->port.membase + UCR2);
1215
1216         imx_setup_ufcr(sport, TXTL_DMA, RXTL_DMA);
1217
1218         sport->dma_is_enabled = 1;
1219 }
1220
1221 static void imx_disable_dma(struct imx_port *sport)
1222 {
1223         unsigned long temp;
1224
1225         /* clear UCR1 */
1226         temp = readl(sport->port.membase + UCR1);
1227         temp &= ~(UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN);
1228         writel(temp, sport->port.membase + UCR1);
1229
1230         /* clear UCR2 */
1231         temp = readl(sport->port.membase + UCR2);
1232         temp &= ~(UCR2_CTSC | UCR2_CTS | UCR2_ATEN);
1233         writel(temp, sport->port.membase + UCR2);
1234
1235         imx_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1236
1237         sport->dma_is_enabled = 0;
1238 }
1239
1240 /* half the RX buffer size */
1241 #define CTSTL 16
1242
1243 static int imx_startup(struct uart_port *port)
1244 {
1245         struct imx_port *sport = (struct imx_port *)port;
1246         int retval, i;
1247         unsigned long flags, temp;
1248
1249         retval = clk_prepare_enable(sport->clk_per);
1250         if (retval)
1251                 return retval;
1252         retval = clk_prepare_enable(sport->clk_ipg);
1253         if (retval) {
1254                 clk_disable_unprepare(sport->clk_per);
1255                 return retval;
1256         }
1257
1258         imx_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1259
1260         /* disable the DREN bit (Data Ready interrupt enable) before
1261          * requesting IRQs
1262          */
1263         temp = readl(sport->port.membase + UCR4);
1264
1265         /* set the trigger level for CTS */
1266         temp &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF);
1267         temp |= CTSTL << UCR4_CTSTL_SHF;
1268
1269         writel(temp & ~UCR4_DREN, sport->port.membase + UCR4);
1270
1271         /* Can we enable the DMA support? */
1272         if (!uart_console(port) && !sport->dma_is_inited)
1273                 imx_uart_dma_init(sport);
1274
1275         spin_lock_irqsave(&sport->port.lock, flags);
1276         /* Reset fifo's and state machines */
1277         i = 100;
1278
1279         temp = readl(sport->port.membase + UCR2);
1280         temp &= ~UCR2_SRST;
1281         writel(temp, sport->port.membase + UCR2);
1282
1283         while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) && (--i > 0))
1284                 udelay(1);
1285
1286         /*
1287          * Finally, clear and enable interrupts
1288          */
1289         writel(USR1_RTSD | USR1_DTRD, sport->port.membase + USR1);
1290         writel(USR2_ORE, sport->port.membase + USR2);
1291
1292         if (sport->dma_is_inited && !sport->dma_is_enabled)
1293                 imx_enable_dma(sport);
1294
1295         temp = readl(sport->port.membase + UCR1);
1296         temp |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN;
1297
1298         writel(temp, sport->port.membase + UCR1);
1299
1300         temp = readl(sport->port.membase + UCR4);
1301         temp |= UCR4_OREN;
1302         writel(temp, sport->port.membase + UCR4);
1303
1304         temp = readl(sport->port.membase + UCR2);
1305         temp |= (UCR2_RXEN | UCR2_TXEN);
1306         if (!sport->have_rtscts)
1307                 temp |= UCR2_IRTS;
1308         /*
1309          * make sure the edge sensitive RTS-irq is disabled,
1310          * we're using RTSD instead.
1311          */
1312         if (!is_imx1_uart(sport))
1313                 temp &= ~UCR2_RTSEN;
1314         writel(temp, sport->port.membase + UCR2);
1315
1316         if (!is_imx1_uart(sport)) {
1317                 temp = readl(sport->port.membase + UCR3);
1318
1319                 /*
1320                  * The effect of RI and DCD differs depending on the UFCR_DCEDTE
1321                  * bit. In DCE mode they control the outputs, in DTE mode they
1322                  * enable the respective irqs. At least the DCD irq cannot be
1323                  * cleared on i.MX25 at least, so it's not usable and must be
1324                  * disabled. I don't have test hardware to check if RI has the
1325                  * same problem but I consider this likely so it's disabled for
1326                  * now, too.
1327                  */
1328                 temp |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP |
1329                         UCR3_DTRDEN | UCR3_RI | UCR3_DCD;
1330
1331                 if (sport->dte_mode)
1332                         temp &= ~(UCR3_RI | UCR3_DCD);
1333
1334                 writel(temp, sport->port.membase + UCR3);
1335         }
1336
1337         /*
1338          * Enable modem status interrupts
1339          */
1340         imx_enable_ms(&sport->port);
1341         spin_unlock_irqrestore(&sport->port.lock, flags);
1342
1343         return 0;
1344 }
1345
1346 static void imx_shutdown(struct uart_port *port)
1347 {
1348         struct imx_port *sport = (struct imx_port *)port;
1349         unsigned long temp;
1350         unsigned long flags;
1351
1352         if (sport->dma_is_enabled) {
1353                 sport->dma_is_rxing = 0;
1354                 sport->dma_is_txing = 0;
1355                 dmaengine_terminate_sync(sport->dma_chan_tx);
1356                 dmaengine_terminate_sync(sport->dma_chan_rx);
1357
1358                 spin_lock_irqsave(&sport->port.lock, flags);
1359                 imx_stop_tx(port);
1360                 imx_stop_rx(port);
1361                 imx_disable_dma(sport);
1362                 spin_unlock_irqrestore(&sport->port.lock, flags);
1363                 imx_uart_dma_exit(sport);
1364         }
1365
1366         mctrl_gpio_disable_ms(sport->gpios);
1367
1368         spin_lock_irqsave(&sport->port.lock, flags);
1369         temp = readl(sport->port.membase + UCR2);
1370         temp &= ~(UCR2_TXEN);
1371         writel(temp, sport->port.membase + UCR2);
1372         spin_unlock_irqrestore(&sport->port.lock, flags);
1373
1374         /*
1375          * Stop our timer.
1376          */
1377         del_timer_sync(&sport->timer);
1378
1379         /*
1380          * Disable all interrupts, port and break condition.
1381          */
1382
1383         spin_lock_irqsave(&sport->port.lock, flags);
1384         temp = readl(sport->port.membase + UCR1);
1385         temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN);
1386
1387         writel(temp, sport->port.membase + UCR1);
1388         spin_unlock_irqrestore(&sport->port.lock, flags);
1389
1390         clk_disable_unprepare(sport->clk_per);
1391         clk_disable_unprepare(sport->clk_ipg);
1392 }
1393
1394 static void imx_flush_buffer(struct uart_port *port)
1395 {
1396         struct imx_port *sport = (struct imx_port *)port;
1397         struct scatterlist *sgl = &sport->tx_sgl[0];
1398         unsigned long temp;
1399         int i = 100, ubir, ubmr, uts;
1400
1401         if (!sport->dma_chan_tx)
1402                 return;
1403
1404         sport->tx_bytes = 0;
1405         dmaengine_terminate_all(sport->dma_chan_tx);
1406         if (sport->dma_is_txing) {
1407                 dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents,
1408                              DMA_TO_DEVICE);
1409                 temp = readl(sport->port.membase + UCR1);
1410                 temp &= ~UCR1_TDMAEN;
1411                 writel(temp, sport->port.membase + UCR1);
1412                 sport->dma_is_txing = false;
1413         }
1414
1415         /*
1416          * According to the Reference Manual description of the UART SRST bit:
1417          * "Reset the transmit and receive state machines,
1418          * all FIFOs and register USR1, USR2, UBIR, UBMR, UBRC, URXD, UTXD
1419          * and UTS[6-3]". As we don't need to restore the old values from
1420          * USR1, USR2, URXD, UTXD, only save/restore the other four registers
1421          */
1422         ubir = readl(sport->port.membase + UBIR);
1423         ubmr = readl(sport->port.membase + UBMR);
1424         uts = readl(sport->port.membase + IMX21_UTS);
1425
1426         temp = readl(sport->port.membase + UCR2);
1427         temp &= ~UCR2_SRST;
1428         writel(temp, sport->port.membase + UCR2);
1429
1430         while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) && (--i > 0))
1431                 udelay(1);
1432
1433         /* Restore the registers */
1434         writel(ubir, sport->port.membase + UBIR);
1435         writel(ubmr, sport->port.membase + UBMR);
1436         writel(uts, sport->port.membase + IMX21_UTS);
1437 }
1438
1439 static void
1440 imx_set_termios(struct uart_port *port, struct ktermios *termios,
1441                    struct ktermios *old)
1442 {
1443         struct imx_port *sport = (struct imx_port *)port;
1444         unsigned long flags;
1445         unsigned long ucr2, old_ucr1, old_ucr2;
1446         unsigned int baud, quot;
1447         unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
1448         unsigned long div, ufcr;
1449         unsigned long num, denom;
1450         uint64_t tdiv64;
1451
1452         /*
1453          * We only support CS7 and CS8.
1454          */
1455         while ((termios->c_cflag & CSIZE) != CS7 &&
1456                (termios->c_cflag & CSIZE) != CS8) {
1457                 termios->c_cflag &= ~CSIZE;
1458                 termios->c_cflag |= old_csize;
1459                 old_csize = CS8;
1460         }
1461
1462         if ((termios->c_cflag & CSIZE) == CS8)
1463                 ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
1464         else
1465                 ucr2 = UCR2_SRST | UCR2_IRTS;
1466
1467         if (termios->c_cflag & CRTSCTS) {
1468                 if (sport->have_rtscts) {
1469                         ucr2 &= ~UCR2_IRTS;
1470
1471                         if (port->rs485.flags & SER_RS485_ENABLED) {
1472                                 /*
1473                                  * RTS is mandatory for rs485 operation, so keep
1474                                  * it under manual control and keep transmitter
1475                                  * disabled.
1476                                  */
1477                                 if (port->rs485.flags &
1478                                     SER_RS485_RTS_AFTER_SEND)
1479                                         imx_port_rts_inactive(sport, &ucr2);
1480                                 else
1481                                         imx_port_rts_active(sport, &ucr2);
1482                         } else {
1483                                 imx_port_rts_auto(sport, &ucr2);
1484                         }
1485                 } else {
1486                         termios->c_cflag &= ~CRTSCTS;
1487                 }
1488         } else if (port->rs485.flags & SER_RS485_ENABLED) {
1489                 /* disable transmitter */
1490                 if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
1491                         imx_port_rts_inactive(sport, &ucr2);
1492                 else
1493                         imx_port_rts_active(sport, &ucr2);
1494         }
1495
1496
1497         if (termios->c_cflag & CSTOPB)
1498                 ucr2 |= UCR2_STPB;
1499         if (termios->c_cflag & PARENB) {
1500                 ucr2 |= UCR2_PREN;
1501                 if (termios->c_cflag & PARODD)
1502                         ucr2 |= UCR2_PROE;
1503         }
1504
1505         del_timer_sync(&sport->timer);
1506
1507         /*
1508          * Ask the core to calculate the divisor for us.
1509          */
1510         baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
1511         quot = uart_get_divisor(port, baud);
1512
1513         spin_lock_irqsave(&sport->port.lock, flags);
1514
1515         sport->port.read_status_mask = 0;
1516         if (termios->c_iflag & INPCK)
1517                 sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
1518         if (termios->c_iflag & (BRKINT | PARMRK))
1519                 sport->port.read_status_mask |= URXD_BRK;
1520
1521         /*
1522          * Characters to ignore
1523          */
1524         sport->port.ignore_status_mask = 0;
1525         if (termios->c_iflag & IGNPAR)
1526                 sport->port.ignore_status_mask |= URXD_PRERR | URXD_FRMERR;
1527         if (termios->c_iflag & IGNBRK) {
1528                 sport->port.ignore_status_mask |= URXD_BRK;
1529                 /*
1530                  * If we're ignoring parity and break indicators,
1531                  * ignore overruns too (for real raw support).
1532                  */
1533                 if (termios->c_iflag & IGNPAR)
1534                         sport->port.ignore_status_mask |= URXD_OVRRUN;
1535         }
1536
1537         if ((termios->c_cflag & CREAD) == 0)
1538                 sport->port.ignore_status_mask |= URXD_DUMMY_READ;
1539
1540         /*
1541          * Update the per-port timeout.
1542          */
1543         uart_update_timeout(port, termios->c_cflag, baud);
1544
1545         /*
1546          * disable interrupts and drain transmitter
1547          */
1548         old_ucr1 = readl(sport->port.membase + UCR1);
1549         writel(old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
1550                         sport->port.membase + UCR1);
1551
1552         while (!(readl(sport->port.membase + USR2) & USR2_TXDC))
1553                 barrier();
1554
1555         /* then, disable everything */
1556         old_ucr2 = readl(sport->port.membase + UCR2);
1557         writel(old_ucr2 & ~(UCR2_TXEN | UCR2_RXEN),
1558                         sport->port.membase + UCR2);
1559         old_ucr2 &= (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN);
1560
1561         /* custom-baudrate handling */
1562         div = sport->port.uartclk / (baud * 16);
1563         if (baud == 38400 && quot != div)
1564                 baud = sport->port.uartclk / (quot * 16);
1565
1566         div = sport->port.uartclk / (baud * 16);
1567         if (div > 7)
1568                 div = 7;
1569         if (!div)
1570                 div = 1;
1571
1572         rational_best_approximation(16 * div * baud, sport->port.uartclk,
1573                 1 << 16, 1 << 16, &num, &denom);
1574
1575         tdiv64 = sport->port.uartclk;
1576         tdiv64 *= num;
1577         do_div(tdiv64, denom * 16 * div);
1578         tty_termios_encode_baud_rate(termios,
1579                                 (speed_t)tdiv64, (speed_t)tdiv64);
1580
1581         num -= 1;
1582         denom -= 1;
1583
1584         ufcr = readl(sport->port.membase + UFCR);
1585         ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
1586         if (sport->dte_mode)
1587                 ufcr |= UFCR_DCEDTE;
1588         writel(ufcr, sport->port.membase + UFCR);
1589
1590         writel(num, sport->port.membase + UBIR);
1591         writel(denom, sport->port.membase + UBMR);
1592
1593         if (!is_imx1_uart(sport))
1594                 writel(sport->port.uartclk / div / 1000,
1595                                 sport->port.membase + IMX21_ONEMS);
1596
1597         writel(old_ucr1, sport->port.membase + UCR1);
1598
1599         /* set the parity, stop bits and data size */
1600         writel(ucr2 | old_ucr2, sport->port.membase + UCR2);
1601
1602         if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
1603                 imx_enable_ms(&sport->port);
1604
1605         spin_unlock_irqrestore(&sport->port.lock, flags);
1606 }
1607
1608 static const char *imx_type(struct uart_port *port)
1609 {
1610         struct imx_port *sport = (struct imx_port *)port;
1611
1612         return sport->port.type == PORT_IMX ? "IMX" : NULL;
1613 }
1614
1615 /*
1616  * Configure/autoconfigure the port.
1617  */
1618 static void imx_config_port(struct uart_port *port, int flags)
1619 {
1620         struct imx_port *sport = (struct imx_port *)port;
1621
1622         if (flags & UART_CONFIG_TYPE)
1623                 sport->port.type = PORT_IMX;
1624 }
1625
1626 /*
1627  * Verify the new serial_struct (for TIOCSSERIAL).
1628  * The only change we allow are to the flags and type, and
1629  * even then only between PORT_IMX and PORT_UNKNOWN
1630  */
1631 static int
1632 imx_verify_port(struct uart_port *port, struct serial_struct *ser)
1633 {
1634         struct imx_port *sport = (struct imx_port *)port;
1635         int ret = 0;
1636
1637         if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
1638                 ret = -EINVAL;
1639         if (sport->port.irq != ser->irq)
1640                 ret = -EINVAL;
1641         if (ser->io_type != UPIO_MEM)
1642                 ret = -EINVAL;
1643         if (sport->port.uartclk / 16 != ser->baud_base)
1644                 ret = -EINVAL;
1645         if (sport->port.mapbase != (unsigned long)ser->iomem_base)
1646                 ret = -EINVAL;
1647         if (sport->port.iobase != ser->port)
1648                 ret = -EINVAL;
1649         if (ser->hub6 != 0)
1650                 ret = -EINVAL;
1651         return ret;
1652 }
1653
1654 #if defined(CONFIG_CONSOLE_POLL)
1655
1656 static int imx_poll_init(struct uart_port *port)
1657 {
1658         struct imx_port *sport = (struct imx_port *)port;
1659         unsigned long flags;
1660         unsigned long temp;
1661         int retval;
1662
1663         retval = clk_prepare_enable(sport->clk_ipg);
1664         if (retval)
1665                 return retval;
1666         retval = clk_prepare_enable(sport->clk_per);
1667         if (retval)
1668                 clk_disable_unprepare(sport->clk_ipg);
1669
1670         imx_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1671
1672         spin_lock_irqsave(&sport->port.lock, flags);
1673
1674         temp = readl(sport->port.membase + UCR1);
1675         if (is_imx1_uart(sport))
1676                 temp |= IMX1_UCR1_UARTCLKEN;
1677         temp |= UCR1_UARTEN | UCR1_RRDYEN;
1678         temp &= ~(UCR1_TXMPTYEN | UCR1_RTSDEN);
1679         writel(temp, sport->port.membase + UCR1);
1680
1681         temp = readl(sport->port.membase + UCR2);
1682         temp |= UCR2_RXEN;
1683         writel(temp, sport->port.membase + UCR2);
1684
1685         spin_unlock_irqrestore(&sport->port.lock, flags);
1686
1687         return 0;
1688 }
1689
1690 static int imx_poll_get_char(struct uart_port *port)
1691 {
1692         if (!(readl_relaxed(port->membase + USR2) & USR2_RDR))
1693                 return NO_POLL_CHAR;
1694
1695         return readl_relaxed(port->membase + URXD0) & URXD_RX_DATA;
1696 }
1697
1698 static void imx_poll_put_char(struct uart_port *port, unsigned char c)
1699 {
1700         unsigned int status;
1701
1702         /* drain */
1703         do {
1704                 status = readl_relaxed(port->membase + USR1);
1705         } while (~status & USR1_TRDY);
1706
1707         /* write */
1708         writel_relaxed(c, port->membase + URTX0);
1709
1710         /* flush */
1711         do {
1712                 status = readl_relaxed(port->membase + USR2);
1713         } while (~status & USR2_TXDC);
1714 }
1715 #endif
1716
1717 static int imx_rs485_config(struct uart_port *port,
1718                             struct serial_rs485 *rs485conf)
1719 {
1720         struct imx_port *sport = (struct imx_port *)port;
1721         unsigned long temp;
1722
1723         /* unimplemented */
1724         rs485conf->delay_rts_before_send = 0;
1725         rs485conf->delay_rts_after_send = 0;
1726
1727         /* RTS is required to control the transmitter */
1728         if (!sport->have_rtscts)
1729                 rs485conf->flags &= ~SER_RS485_ENABLED;
1730
1731         if (rs485conf->flags & SER_RS485_ENABLED) {
1732                 /* disable transmitter */
1733                 temp = readl(sport->port.membase + UCR2);
1734                 if (rs485conf->flags & SER_RS485_RTS_AFTER_SEND)
1735                         imx_port_rts_inactive(sport, &temp);
1736                 else
1737                         imx_port_rts_active(sport, &temp);
1738                 writel(temp, sport->port.membase + UCR2);
1739         }
1740
1741         /* Make sure Rx is enabled in case Tx is active with Rx disabled */
1742         if (!(rs485conf->flags & SER_RS485_ENABLED) ||
1743             rs485conf->flags & SER_RS485_RX_DURING_TX) {
1744                 temp = readl(sport->port.membase + UCR2);
1745                 temp |= UCR2_RXEN;
1746                 writel(temp, sport->port.membase + UCR2);
1747         }
1748
1749         port->rs485 = *rs485conf;
1750
1751         return 0;
1752 }
1753
1754 static const struct uart_ops imx_pops = {
1755         .tx_empty       = imx_tx_empty,
1756         .set_mctrl      = imx_set_mctrl,
1757         .get_mctrl      = imx_get_mctrl,
1758         .stop_tx        = imx_stop_tx,
1759         .start_tx       = imx_start_tx,
1760         .stop_rx        = imx_stop_rx,
1761         .enable_ms      = imx_enable_ms,
1762         .break_ctl      = imx_break_ctl,
1763         .startup        = imx_startup,
1764         .shutdown       = imx_shutdown,
1765         .flush_buffer   = imx_flush_buffer,
1766         .set_termios    = imx_set_termios,
1767         .type           = imx_type,
1768         .config_port    = imx_config_port,
1769         .verify_port    = imx_verify_port,
1770 #if defined(CONFIG_CONSOLE_POLL)
1771         .poll_init      = imx_poll_init,
1772         .poll_get_char  = imx_poll_get_char,
1773         .poll_put_char  = imx_poll_put_char,
1774 #endif
1775 };
1776
1777 static struct imx_port *imx_ports[UART_NR];
1778
1779 #ifdef CONFIG_SERIAL_IMX_CONSOLE
1780 static void imx_console_putchar(struct uart_port *port, int ch)
1781 {
1782         struct imx_port *sport = (struct imx_port *)port;
1783
1784         while (readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)
1785                 barrier();
1786
1787         writel(ch, sport->port.membase + URTX0);
1788 }
1789
1790 /*
1791  * Interrupts are disabled on entering
1792  */
1793 static void
1794 imx_console_write(struct console *co, const char *s, unsigned int count)
1795 {
1796         struct imx_port *sport = imx_ports[co->index];
1797         struct imx_port_ucrs old_ucr;
1798         unsigned int ucr1;
1799         unsigned long flags = 0;
1800         int locked = 1;
1801         int retval;
1802
1803         retval = clk_enable(sport->clk_per);
1804         if (retval)
1805                 return;
1806         retval = clk_enable(sport->clk_ipg);
1807         if (retval) {
1808                 clk_disable(sport->clk_per);
1809                 return;
1810         }
1811
1812         if (sport->port.sysrq)
1813                 locked = 0;
1814         else if (oops_in_progress)
1815                 locked = spin_trylock_irqsave(&sport->port.lock, flags);
1816         else
1817                 spin_lock_irqsave(&sport->port.lock, flags);
1818
1819         /*
1820          *      First, save UCR1/2/3 and then disable interrupts
1821          */
1822         imx_port_ucrs_save(&sport->port, &old_ucr);
1823         ucr1 = old_ucr.ucr1;
1824
1825         if (is_imx1_uart(sport))
1826                 ucr1 |= IMX1_UCR1_UARTCLKEN;
1827         ucr1 |= UCR1_UARTEN;
1828         ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN);
1829
1830         writel(ucr1, sport->port.membase + UCR1);
1831
1832         writel(old_ucr.ucr2 | UCR2_TXEN, sport->port.membase + UCR2);
1833
1834         uart_console_write(&sport->port, s, count, imx_console_putchar);
1835
1836         /*
1837          *      Finally, wait for transmitter to become empty
1838          *      and restore UCR1/2/3
1839          */
1840         while (!(readl(sport->port.membase + USR2) & USR2_TXDC));
1841
1842         imx_port_ucrs_restore(&sport->port, &old_ucr);
1843
1844         if (locked)
1845                 spin_unlock_irqrestore(&sport->port.lock, flags);
1846
1847         clk_disable(sport->clk_ipg);
1848         clk_disable(sport->clk_per);
1849 }
1850
1851 /*
1852  * If the port was already initialised (eg, by a boot loader),
1853  * try to determine the current setup.
1854  */
1855 static void __init
1856 imx_console_get_options(struct imx_port *sport, int *baud,
1857                            int *parity, int *bits)
1858 {
1859
1860         if (readl(sport->port.membase + UCR1) & UCR1_UARTEN) {
1861                 /* ok, the port was enabled */
1862                 unsigned int ucr2, ubir, ubmr, uartclk;
1863                 unsigned int baud_raw;
1864                 unsigned int ucfr_rfdiv;
1865
1866                 ucr2 = readl(sport->port.membase + UCR2);
1867
1868                 *parity = 'n';
1869                 if (ucr2 & UCR2_PREN) {
1870                         if (ucr2 & UCR2_PROE)
1871                                 *parity = 'o';
1872                         else
1873                                 *parity = 'e';
1874                 }
1875
1876                 if (ucr2 & UCR2_WS)
1877                         *bits = 8;
1878                 else
1879                         *bits = 7;
1880
1881                 ubir = readl(sport->port.membase + UBIR) & 0xffff;
1882                 ubmr = readl(sport->port.membase + UBMR) & 0xffff;
1883
1884                 ucfr_rfdiv = (readl(sport->port.membase + UFCR) & UFCR_RFDIV) >> 7;
1885                 if (ucfr_rfdiv == 6)
1886                         ucfr_rfdiv = 7;
1887                 else
1888                         ucfr_rfdiv = 6 - ucfr_rfdiv;
1889
1890                 uartclk = clk_get_rate(sport->clk_per);
1891                 uartclk /= ucfr_rfdiv;
1892
1893                 {       /*
1894                          * The next code provides exact computation of
1895                          *   baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
1896                          * without need of float support or long long division,
1897                          * which would be required to prevent 32bit arithmetic overflow
1898                          */
1899                         unsigned int mul = ubir + 1;
1900                         unsigned int div = 16 * (ubmr + 1);
1901                         unsigned int rem = uartclk % div;
1902
1903                         baud_raw = (uartclk / div) * mul;
1904                         baud_raw += (rem * mul + div / 2) / div;
1905                         *baud = (baud_raw + 50) / 100 * 100;
1906                 }
1907
1908                 if (*baud != baud_raw)
1909                         pr_info("Console IMX rounded baud rate from %d to %d\n",
1910                                 baud_raw, *baud);
1911         }
1912 }
1913
1914 static int __init
1915 imx_console_setup(struct console *co, char *options)
1916 {
1917         struct imx_port *sport;
1918         int baud = 9600;
1919         int bits = 8;
1920         int parity = 'n';
1921         int flow = 'n';
1922         int retval;
1923
1924         /*
1925          * Check whether an invalid uart number has been specified, and
1926          * if so, search for the first available port that does have
1927          * console support.
1928          */
1929         if (co->index == -1 || co->index >= ARRAY_SIZE(imx_ports))
1930                 co->index = 0;
1931         sport = imx_ports[co->index];
1932         if (sport == NULL)
1933                 return -ENODEV;
1934
1935         /* For setting the registers, we only need to enable the ipg clock. */
1936         retval = clk_prepare_enable(sport->clk_ipg);
1937         if (retval)
1938                 goto error_console;
1939
1940         if (options)
1941                 uart_parse_options(options, &baud, &parity, &bits, &flow);
1942         else
1943                 imx_console_get_options(sport, &baud, &parity, &bits);
1944
1945         imx_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1946
1947         retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
1948
1949         clk_disable(sport->clk_ipg);
1950         if (retval) {
1951                 clk_unprepare(sport->clk_ipg);
1952                 goto error_console;
1953         }
1954
1955         retval = clk_prepare(sport->clk_per);
1956         if (retval)
1957                 clk_disable_unprepare(sport->clk_ipg);
1958
1959 error_console:
1960         return retval;
1961 }
1962
1963 static struct uart_driver imx_reg;
1964 static struct console imx_console = {
1965         .name           = DEV_NAME,
1966         .write          = imx_console_write,
1967         .device         = uart_console_device,
1968         .setup          = imx_console_setup,
1969         .flags          = CON_PRINTBUFFER,
1970         .index          = -1,
1971         .data           = &imx_reg,
1972 };
1973
1974 #define IMX_CONSOLE     &imx_console
1975
1976 #ifdef CONFIG_OF
1977 static void imx_console_early_putchar(struct uart_port *port, int ch)
1978 {
1979         while (readl_relaxed(port->membase + IMX21_UTS) & UTS_TXFULL)
1980                 cpu_relax();
1981
1982         writel_relaxed(ch, port->membase + URTX0);
1983 }
1984
1985 static void imx_console_early_write(struct console *con, const char *s,
1986                                     unsigned count)
1987 {
1988         struct earlycon_device *dev = con->data;
1989
1990         uart_console_write(&dev->port, s, count, imx_console_early_putchar);
1991 }
1992
1993 static int __init
1994 imx_console_early_setup(struct earlycon_device *dev, const char *opt)
1995 {
1996         if (!dev->port.membase)
1997                 return -ENODEV;
1998
1999         dev->con->write = imx_console_early_write;
2000
2001         return 0;
2002 }
2003 OF_EARLYCON_DECLARE(ec_imx6q, "fsl,imx6q-uart", imx_console_early_setup);
2004 OF_EARLYCON_DECLARE(ec_imx21, "fsl,imx21-uart", imx_console_early_setup);
2005 #endif
2006
2007 #else
2008 #define IMX_CONSOLE     NULL
2009 #endif
2010
2011 static struct uart_driver imx_reg = {
2012         .owner          = THIS_MODULE,
2013         .driver_name    = DRIVER_NAME,
2014         .dev_name       = DEV_NAME,
2015         .major          = SERIAL_IMX_MAJOR,
2016         .minor          = MINOR_START,
2017         .nr             = ARRAY_SIZE(imx_ports),
2018         .cons           = IMX_CONSOLE,
2019 };
2020
2021 #ifdef CONFIG_OF
2022 /*
2023  * This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
2024  * could successfully get all information from dt or a negative errno.
2025  */
2026 static int serial_imx_probe_dt(struct imx_port *sport,
2027                 struct platform_device *pdev)
2028 {
2029         struct device_node *np = pdev->dev.of_node;
2030         int ret;
2031
2032         sport->devdata = of_device_get_match_data(&pdev->dev);
2033         if (!sport->devdata)
2034                 /* no device tree device */
2035                 return 1;
2036
2037         ret = of_alias_get_id(np, "serial");
2038         if (ret < 0) {
2039                 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
2040                 return ret;
2041         }
2042         sport->port.line = ret;
2043
2044         if (of_get_property(np, "uart-has-rtscts", NULL) ||
2045             of_get_property(np, "fsl,uart-has-rtscts", NULL) /* deprecated */)
2046                 sport->have_rtscts = 1;
2047
2048         if (of_get_property(np, "fsl,dte-mode", NULL))
2049                 sport->dte_mode = 1;
2050
2051         return 0;
2052 }
2053 #else
2054 static inline int serial_imx_probe_dt(struct imx_port *sport,
2055                 struct platform_device *pdev)
2056 {
2057         return 1;
2058 }
2059 #endif
2060
2061 static void serial_imx_probe_pdata(struct imx_port *sport,
2062                 struct platform_device *pdev)
2063 {
2064         struct imxuart_platform_data *pdata = dev_get_platdata(&pdev->dev);
2065
2066         sport->port.line = pdev->id;
2067         sport->devdata = (struct imx_uart_data  *) pdev->id_entry->driver_data;
2068
2069         if (!pdata)
2070                 return;
2071
2072         if (pdata->flags & IMXUART_HAVE_RTSCTS)
2073                 sport->have_rtscts = 1;
2074 }
2075
2076 static int serial_imx_probe(struct platform_device *pdev)
2077 {
2078         struct imx_port *sport;
2079         void __iomem *base;
2080         int ret = 0, reg;
2081         struct resource *res;
2082         int txirq, rxirq, rtsirq;
2083
2084         sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
2085         if (!sport)
2086                 return -ENOMEM;
2087
2088         ret = serial_imx_probe_dt(sport, pdev);
2089         if (ret > 0)
2090                 serial_imx_probe_pdata(sport, pdev);
2091         else if (ret < 0)
2092                 return ret;
2093
2094         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2095         base = devm_ioremap_resource(&pdev->dev, res);
2096         if (IS_ERR(base))
2097                 return PTR_ERR(base);
2098
2099         rxirq = platform_get_irq(pdev, 0);
2100         txirq = platform_get_irq(pdev, 1);
2101         rtsirq = platform_get_irq(pdev, 2);
2102
2103         sport->port.dev = &pdev->dev;
2104         sport->port.mapbase = res->start;
2105         sport->port.membase = base;
2106         sport->port.type = PORT_IMX,
2107         sport->port.iotype = UPIO_MEM;
2108         sport->port.irq = rxirq;
2109         sport->port.fifosize = 32;
2110         sport->port.ops = &imx_pops;
2111         sport->port.rs485_config = imx_rs485_config;
2112         sport->port.rs485.flags =
2113                 SER_RS485_RTS_ON_SEND | SER_RS485_RX_DURING_TX;
2114         sport->port.flags = UPF_BOOT_AUTOCONF;
2115         init_timer(&sport->timer);
2116         sport->timer.function = imx_timeout;
2117         sport->timer.data     = (unsigned long)sport;
2118
2119         sport->gpios = mctrl_gpio_init(&sport->port, 0);
2120         if (IS_ERR(sport->gpios))
2121                 return PTR_ERR(sport->gpios);
2122
2123         sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
2124         if (IS_ERR(sport->clk_ipg)) {
2125                 ret = PTR_ERR(sport->clk_ipg);
2126                 dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
2127                 return ret;
2128         }
2129
2130         sport->clk_per = devm_clk_get(&pdev->dev, "per");
2131         if (IS_ERR(sport->clk_per)) {
2132                 ret = PTR_ERR(sport->clk_per);
2133                 dev_err(&pdev->dev, "failed to get per clk: %d\n", ret);
2134                 return ret;
2135         }
2136
2137         sport->port.uartclk = clk_get_rate(sport->clk_per);
2138
2139         /* For register access, we only need to enable the ipg clock. */
2140         ret = clk_prepare_enable(sport->clk_ipg);
2141         if (ret) {
2142                 dev_err(&pdev->dev, "failed to enable per clk: %d\n", ret);
2143                 return ret;
2144         }
2145
2146         /* Disable interrupts before requesting them */
2147         reg = readl_relaxed(sport->port.membase + UCR1);
2148         reg &= ~(UCR1_ADEN | UCR1_TRDYEN | UCR1_IDEN | UCR1_RRDYEN |
2149                  UCR1_TXMPTYEN | UCR1_RTSDEN);
2150         writel_relaxed(reg, sport->port.membase + UCR1);
2151
2152         clk_disable_unprepare(sport->clk_ipg);
2153
2154         /*
2155          * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
2156          * chips only have one interrupt.
2157          */
2158         if (txirq > 0) {
2159                 ret = devm_request_irq(&pdev->dev, rxirq, imx_rxint, 0,
2160                                        dev_name(&pdev->dev), sport);
2161                 if (ret) {
2162                         dev_err(&pdev->dev, "failed to request rx irq: %d\n",
2163                                 ret);
2164                         return ret;
2165                 }
2166
2167                 ret = devm_request_irq(&pdev->dev, txirq, imx_txint, 0,
2168                                        dev_name(&pdev->dev), sport);
2169                 if (ret) {
2170                         dev_err(&pdev->dev, "failed to request tx irq: %d\n",
2171                                 ret);
2172                         return ret;
2173                 }
2174         } else {
2175                 ret = devm_request_irq(&pdev->dev, rxirq, imx_int, 0,
2176                                        dev_name(&pdev->dev), sport);
2177                 if (ret) {
2178                         dev_err(&pdev->dev, "failed to request irq: %d\n", ret);
2179                         return ret;
2180                 }
2181         }
2182
2183         imx_ports[sport->port.line] = sport;
2184
2185         platform_set_drvdata(pdev, sport);
2186
2187         return uart_add_one_port(&imx_reg, &sport->port);
2188 }
2189
2190 static int serial_imx_remove(struct platform_device *pdev)
2191 {
2192         struct imx_port *sport = platform_get_drvdata(pdev);
2193
2194         return uart_remove_one_port(&imx_reg, &sport->port);
2195 }
2196
2197 static void serial_imx_restore_context(struct imx_port *sport)
2198 {
2199         if (!sport->context_saved)
2200                 return;
2201
2202         writel(sport->saved_reg[4], sport->port.membase + UFCR);
2203         writel(sport->saved_reg[5], sport->port.membase + UESC);
2204         writel(sport->saved_reg[6], sport->port.membase + UTIM);
2205         writel(sport->saved_reg[7], sport->port.membase + UBIR);
2206         writel(sport->saved_reg[8], sport->port.membase + UBMR);
2207         writel(sport->saved_reg[9], sport->port.membase + IMX21_UTS);
2208         writel(sport->saved_reg[0], sport->port.membase + UCR1);
2209         writel(sport->saved_reg[1] | UCR2_SRST, sport->port.membase + UCR2);
2210         writel(sport->saved_reg[2], sport->port.membase + UCR3);
2211         writel(sport->saved_reg[3], sport->port.membase + UCR4);
2212         sport->context_saved = false;
2213 }
2214
2215 static void serial_imx_save_context(struct imx_port *sport)
2216 {
2217         /* Save necessary regs */
2218         sport->saved_reg[0] = readl(sport->port.membase + UCR1);
2219         sport->saved_reg[1] = readl(sport->port.membase + UCR2);
2220         sport->saved_reg[2] = readl(sport->port.membase + UCR3);
2221         sport->saved_reg[3] = readl(sport->port.membase + UCR4);
2222         sport->saved_reg[4] = readl(sport->port.membase + UFCR);
2223         sport->saved_reg[5] = readl(sport->port.membase + UESC);
2224         sport->saved_reg[6] = readl(sport->port.membase + UTIM);
2225         sport->saved_reg[7] = readl(sport->port.membase + UBIR);
2226         sport->saved_reg[8] = readl(sport->port.membase + UBMR);
2227         sport->saved_reg[9] = readl(sport->port.membase + IMX21_UTS);
2228         sport->context_saved = true;
2229 }
2230
2231 static void serial_imx_enable_wakeup(struct imx_port *sport, bool on)
2232 {
2233         unsigned int val;
2234
2235         val = readl(sport->port.membase + UCR3);
2236         if (on)
2237                 val |= UCR3_AWAKEN;
2238         else
2239                 val &= ~UCR3_AWAKEN;
2240         writel(val, sport->port.membase + UCR3);
2241
2242         val = readl(sport->port.membase + UCR1);
2243         if (on)
2244                 val |= UCR1_RTSDEN;
2245         else
2246                 val &= ~UCR1_RTSDEN;
2247         writel(val, sport->port.membase + UCR1);
2248 }
2249
2250 static int imx_serial_port_suspend_noirq(struct device *dev)
2251 {
2252         struct platform_device *pdev = to_platform_device(dev);
2253         struct imx_port *sport = platform_get_drvdata(pdev);
2254         int ret;
2255
2256         ret = clk_enable(sport->clk_ipg);
2257         if (ret)
2258                 return ret;
2259
2260         serial_imx_save_context(sport);
2261
2262         clk_disable(sport->clk_ipg);
2263
2264         return 0;
2265 }
2266
2267 static int imx_serial_port_resume_noirq(struct device *dev)
2268 {
2269         struct platform_device *pdev = to_platform_device(dev);
2270         struct imx_port *sport = platform_get_drvdata(pdev);
2271         int ret;
2272
2273         ret = clk_enable(sport->clk_ipg);
2274         if (ret)
2275                 return ret;
2276
2277         serial_imx_restore_context(sport);
2278
2279         clk_disable(sport->clk_ipg);
2280
2281         return 0;
2282 }
2283
2284 static int imx_serial_port_suspend(struct device *dev)
2285 {
2286         struct platform_device *pdev = to_platform_device(dev);
2287         struct imx_port *sport = platform_get_drvdata(pdev);
2288
2289         /* enable wakeup from i.MX UART */
2290         serial_imx_enable_wakeup(sport, true);
2291
2292         uart_suspend_port(&imx_reg, &sport->port);
2293
2294         /* Needed to enable clock in suspend_noirq */
2295         return clk_prepare(sport->clk_ipg);
2296 }
2297
2298 static int imx_serial_port_resume(struct device *dev)
2299 {
2300         struct platform_device *pdev = to_platform_device(dev);
2301         struct imx_port *sport = platform_get_drvdata(pdev);
2302
2303         /* disable wakeup from i.MX UART */
2304         serial_imx_enable_wakeup(sport, false);
2305
2306         uart_resume_port(&imx_reg, &sport->port);
2307
2308         clk_unprepare(sport->clk_ipg);
2309
2310         return 0;
2311 }
2312
2313 static const struct dev_pm_ops imx_serial_port_pm_ops = {
2314         .suspend_noirq = imx_serial_port_suspend_noirq,
2315         .resume_noirq = imx_serial_port_resume_noirq,
2316         .suspend = imx_serial_port_suspend,
2317         .resume = imx_serial_port_resume,
2318 };
2319
2320 static struct platform_driver serial_imx_driver = {
2321         .probe          = serial_imx_probe,
2322         .remove         = serial_imx_remove,
2323
2324         .id_table       = imx_uart_devtype,
2325         .driver         = {
2326                 .name   = "imx-uart",
2327                 .of_match_table = imx_uart_dt_ids,
2328                 .pm     = &imx_serial_port_pm_ops,
2329         },
2330 };
2331
2332 static int __init imx_serial_init(void)
2333 {
2334         int ret = uart_register_driver(&imx_reg);
2335
2336         if (ret)
2337                 return ret;
2338
2339         ret = platform_driver_register(&serial_imx_driver);
2340         if (ret != 0)
2341                 uart_unregister_driver(&imx_reg);
2342
2343         return ret;
2344 }
2345
2346 static void __exit imx_serial_exit(void)
2347 {
2348         platform_driver_unregister(&serial_imx_driver);
2349         uart_unregister_driver(&imx_reg);
2350 }
2351
2352 module_init(imx_serial_init);
2353 module_exit(imx_serial_exit);
2354
2355 MODULE_AUTHOR("Sascha Hauer");
2356 MODULE_DESCRIPTION("IMX generic serial port driver");
2357 MODULE_LICENSE("GPL");
2358 MODULE_ALIAS("platform:imx-uart");