drivers/spi/spi-rockchip.c

   1 /*
   2  * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd
   3  * Author: Addy Ke <addy.ke@rock-chips.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  */
  15
  16 #include <linux/clk.h>
  17 #include <linux/dmaengine.h>
  18 #include <linux/module.h>
  19 #include <linux/of.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/spi/spi.h>
  22 #include <linux/pm_runtime.h>
  23 #include <linux/scatterlist.h>
  24
  25 #define DRIVER_NAME "rockchip-spi"
  26
  27 /* SPI register offsets */
  28 #define ROCKCHIP_SPI_CTRLR0                     0x0000
  29 #define ROCKCHIP_SPI_CTRLR1                     0x0004
  30 #define ROCKCHIP_SPI_SSIENR                     0x0008
  31 #define ROCKCHIP_SPI_SER                        0x000c
  32 #define ROCKCHIP_SPI_BAUDR                      0x0010
  33 #define ROCKCHIP_SPI_TXFTLR                     0x0014
  34 #define ROCKCHIP_SPI_RXFTLR                     0x0018
  35 #define ROCKCHIP_SPI_TXFLR                      0x001c
  36 #define ROCKCHIP_SPI_RXFLR                      0x0020
  37 #define ROCKCHIP_SPI_SR                         0x0024
  38 #define ROCKCHIP_SPI_IPR                        0x0028
  39 #define ROCKCHIP_SPI_IMR                        0x002c
  40 #define ROCKCHIP_SPI_ISR                        0x0030
  41 #define ROCKCHIP_SPI_RISR                       0x0034
  42 #define ROCKCHIP_SPI_ICR                        0x0038
  43 #define ROCKCHIP_SPI_DMACR                      0x003c
  44 #define ROCKCHIP_SPI_DMATDLR            0x0040
  45 #define ROCKCHIP_SPI_DMARDLR            0x0044
  46 #define ROCKCHIP_SPI_TXDR                       0x0400
  47 #define ROCKCHIP_SPI_RXDR                       0x0800
  48
  49 /* Bit fields in CTRLR0 */
  50 #define CR0_DFS_OFFSET                          0
  51
  52 #define CR0_CFS_OFFSET                          2
  53
  54 #define CR0_SCPH_OFFSET                         6
  55
  56 #define CR0_SCPOL_OFFSET                        7
  57
  58 #define CR0_CSM_OFFSET                          8
  59 #define CR0_CSM_KEEP                            0x0
  60 /* ss_n be high for half sclk_out cycles */
  61 #define CR0_CSM_HALF                            0X1
  62 /* ss_n be high for one sclk_out cycle */
  63 #define CR0_CSM_ONE                                     0x2
  64
  65 /* ss_n to sclk_out delay */
  66 #define CR0_SSD_OFFSET                          10
  67 /*
  68  * The period between ss_n active and
  69  * sclk_out active is half sclk_out cycles
  70  */
  71 #define CR0_SSD_HALF                            0x0
  72 /*
  73  * The period between ss_n active and
  74  * sclk_out active is one sclk_out cycle
  75  */
  76 #define CR0_SSD_ONE                                     0x1
  77
  78 #define CR0_EM_OFFSET                           11
  79 #define CR0_EM_LITTLE                           0x0
  80 #define CR0_EM_BIG                                      0x1
  81
  82 #define CR0_FBM_OFFSET                          12
  83 #define CR0_FBM_MSB                                     0x0
  84 #define CR0_FBM_LSB                                     0x1
  85
  86 #define CR0_BHT_OFFSET                          13
  87 #define CR0_BHT_16BIT                           0x0
  88 #define CR0_BHT_8BIT                            0x1
  89
  90 #define CR0_RSD_OFFSET                          14
  91
  92 #define CR0_FRF_OFFSET                          16
  93 #define CR0_FRF_SPI                                     0x0
  94 #define CR0_FRF_SSP                                     0x1
  95 #define CR0_FRF_MICROWIRE                       0x2
  96
  97 #define CR0_XFM_OFFSET                          18
  98 #define CR0_XFM_MASK                            (0x03 << SPI_XFM_OFFSET)
  99 #define CR0_XFM_TR                                      0x0
 100 #define CR0_XFM_TO                                      0x1
 101 #define CR0_XFM_RO                                      0x2
 102
 103 #define CR0_OPM_OFFSET                          20
 104 #define CR0_OPM_MASTER                          0x0
 105 #define CR0_OPM_SLAVE                           0x1
 106
 107 #define CR0_MTM_OFFSET                          0x21
 108
 109 /* Bit fields in SER, 2bit */
 110 #define SER_MASK                                        0x3
 111
 112 /* Bit fields in SR, 5bit */
 113 #define SR_MASK                                         0x1f
 114 #define SR_BUSY                                         (1 << 0)
 115 #define SR_TF_FULL                                      (1 << 1)
 116 #define SR_TF_EMPTY                                     (1 << 2)
 117 #define SR_RF_EMPTY                                     (1 << 3)
 118 #define SR_RF_FULL                                      (1 << 4)
 119
 120 /* Bit fields in ISR, IMR, ISR, RISR, 5bit */
 121 #define INT_MASK                                        0x1f
 122 #define INT_TF_EMPTY                            (1 << 0)
 123 #define INT_TF_OVERFLOW                         (1 << 1)
 124 #define INT_RF_UNDERFLOW                        (1 << 2)
 125 #define INT_RF_OVERFLOW                         (1 << 3)
 126 #define INT_RF_FULL                                     (1 << 4)
 127
 128 /* Bit fields in ICR, 4bit */
 129 #define ICR_MASK                                        0x0f
 130 #define ICR_ALL                                         (1 << 0)
 131 #define ICR_RF_UNDERFLOW                        (1 << 1)
 132 #define ICR_RF_OVERFLOW                         (1 << 2)
 133 #define ICR_TF_OVERFLOW                         (1 << 3)
 134
 135 /* Bit fields in DMACR */
 136 #define RF_DMA_EN                                       (1 << 0)
 137 #define TF_DMA_EN                                       (1 << 1)
 138
 139 #define RXBUSY                                          (1 << 0)
 140 #define TXBUSY                                          (1 << 1)
 141
 142 /* sclk_out: spi master internal logic in rk3x can support 50Mhz */
 143 #define MAX_SCLK_OUT            50000000
 144
 145 /*
 146  * SPI_CTRLR1 is 16-bits, so we should support lengths of 0xffff + 1. However,
 147  * the controller seems to hang when given 0x10000, so stick with this for now.
 148  */
 149 #define ROCKCHIP_SPI_MAX_TRANLEN                0xffff
 150
 151 enum rockchip_ssi_type {
 152         SSI_MOTO_SPI = 0,
 153         SSI_TI_SSP,
 154         SSI_NS_MICROWIRE,
 155 };
 156
 157 struct rockchip_spi_dma_data {
 158         struct dma_chan *ch;
 159         enum dma_transfer_direction direction;
 160         dma_addr_t addr;
 161 };
 162
 163 struct rockchip_spi {
 164         struct device *dev;
 165         struct spi_master *master;
 166
 167         struct clk *spiclk;
 168         struct clk *apb_pclk;
 169
 170         void __iomem *regs;
 171         /*depth of the FIFO buffer */
 172         u32 fifo_len;
 173         /* max bus freq supported */
 174         u32 max_freq;
 175         /* supported slave numbers */
 176         enum rockchip_ssi_type type;
 177
 178         u16 mode;
 179         u8 tmode;
 180         u8 bpw;
 181         u8 n_bytes;
 182         u32 rsd_nsecs;
 183         unsigned len;
 184         u32 speed;
 185
 186         const void *tx;
 187         const void *tx_end;
 188         void *rx;
 189         void *rx_end;
 190
 191         u32 state;
 192         /* protect state */
 193         spinlock_t lock;
 194
 195         u32 use_dma;
 196         struct sg_table tx_sg;
 197         struct sg_table rx_sg;
 198         struct rockchip_spi_dma_data dma_rx;
 199         struct rockchip_spi_dma_data dma_tx;
 200         struct dma_slave_caps dma_caps;
 201 };
 202
 203 static inline void spi_enable_chip(struct rockchip_spi *rs, int enable)
 204 {
 205         writel_relaxed((enable ? 1 : 0), rs->regs + ROCKCHIP_SPI_SSIENR);
 206 }
 207
 208 static inline void spi_set_clk(struct rockchip_spi *rs, u16 div)
 209 {
 210         writel_relaxed(div, rs->regs + ROCKCHIP_SPI_BAUDR);
 211 }
 212
 213 static inline void flush_fifo(struct rockchip_spi *rs)
 214 {
 215         while (readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR))
 216                 readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
 217 }
 218
 219 static inline void wait_for_idle(struct rockchip_spi *rs)
 220 {
 221         unsigned long timeout = jiffies + msecs_to_jiffies(5);
 222
 223         do {
 224                 if (!(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY))
 225                         return;
 226         } while (!time_after(jiffies, timeout));
 227
 228         dev_warn(rs->dev, "spi controller is in busy state!\n");
 229 }
 230
 231 static u32 get_fifo_len(struct rockchip_spi *rs)
 232 {
 233         u32 fifo;
 234
 235         for (fifo = 2; fifo < 32; fifo++) {
 236                 writel_relaxed(fifo, rs->regs + ROCKCHIP_SPI_TXFTLR);
 237                 if (fifo != readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFTLR))
 238                         break;
 239         }
 240
 241         writel_relaxed(0, rs->regs + ROCKCHIP_SPI_TXFTLR);
 242
 243         return (fifo == 31) ? 0 : fifo;
 244 }
 245
 246 static inline u32 tx_max(struct rockchip_spi *rs)
 247 {
 248         u32 tx_left, tx_room;
 249
 250         tx_left = (rs->tx_end - rs->tx) / rs->n_bytes;
 251         tx_room = rs->fifo_len - readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFLR);
 252
 253         return min(tx_left, tx_room);
 254 }
 255
 256 static inline u32 rx_max(struct rockchip_spi *rs)
 257 {
 258         u32 rx_left = (rs->rx_end - rs->rx) / rs->n_bytes;
 259         u32 rx_room = (u32)readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
 260
 261         return min(rx_left, rx_room);
 262 }
 263
 264 static void rockchip_spi_set_cs(struct spi_device *spi, bool enable)
 265 {
 266         u32 ser;
 267         struct spi_master *master = spi->master;
 268         struct rockchip_spi *rs = spi_master_get_devdata(master);
 269
 270         pm_runtime_get_sync(rs->dev);
 271
 272         ser = readl_relaxed(rs->regs + ROCKCHIP_SPI_SER) & SER_MASK;
 273
 274         /*
 275          * drivers/spi/spi.c:
 276          * static void spi_set_cs(struct spi_device *spi, bool enable)
 277          * {
 278          *              if (spi->mode & SPI_CS_HIGH)
 279          *                      enable = !enable;
 280          *
 281          *              if (spi->cs_gpio >= 0)
 282          *                      gpio_set_value(spi->cs_gpio, !enable);
 283          *              else if (spi->master->set_cs)
 284          *              spi->master->set_cs(spi, !enable);
 285          * }
 286          *
 287          * Note: enable(rockchip_spi_set_cs) = !enable(spi_set_cs)
 288          */
 289         if (!enable)
 290                 ser |= 1 << spi->chip_select;
 291         else
 292                 ser &= ~(1 << spi->chip_select);
 293
 294         writel_relaxed(ser, rs->regs + ROCKCHIP_SPI_SER);
 295
 296         pm_runtime_put_sync(rs->dev);
 297 }
 298
 299 static int rockchip_spi_prepare_message(struct spi_master *master,
 300                                         struct spi_message *msg)
 301 {
 302         struct rockchip_spi *rs = spi_master_get_devdata(master);
 303         struct spi_device *spi = msg->spi;
 304
 305         rs->mode = spi->mode;
 306
 307         return 0;
 308 }
 309
 310 static void rockchip_spi_handle_err(struct spi_master *master,
 311                                     struct spi_message *msg)
 312 {
 313         unsigned long flags;
 314         struct rockchip_spi *rs = spi_master_get_devdata(master);
 315
 316         spin_lock_irqsave(&rs->lock, flags);
 317
 318         /*
 319          * For DMA mode, we need terminate DMA channel and flush
 320          * fifo for the next transfer if DMA thansfer timeout.
 321          * handle_err() was called by core if transfer failed.
 322          * Maybe it is reasonable for error handling here.
 323          */
 324         if (rs->use_dma) {
 325                 if (rs->state & RXBUSY) {
 326                         dmaengine_terminate_async(rs->dma_rx.ch);
 327                         flush_fifo(rs);
 328                 }
 329
 330                 if (rs->state & TXBUSY)
 331                         dmaengine_terminate_async(rs->dma_tx.ch);
 332         }
 333
 334         spin_unlock_irqrestore(&rs->lock, flags);
 335 }
 336
 337 static int rockchip_spi_unprepare_message(struct spi_master *master,
 338                                           struct spi_message *msg)
 339 {
 340         struct rockchip_spi *rs = spi_master_get_devdata(master);
 341
 342         spi_enable_chip(rs, 0);
 343
 344         return 0;
 345 }
 346
 347 static void rockchip_spi_pio_writer(struct rockchip_spi *rs)
 348 {
 349         u32 max = tx_max(rs);
 350         u32 txw = 0;
 351
 352         while (max--) {
 353                 if (rs->n_bytes == 1)
 354                         txw = *(u8 *)(rs->tx);
 355                 else
 356                         txw = *(u16 *)(rs->tx);
 357
 358                 writel_relaxed(txw, rs->regs + ROCKCHIP_SPI_TXDR);
 359                 rs->tx += rs->n_bytes;
 360         }
 361 }
 362
 363 static void rockchip_spi_pio_reader(struct rockchip_spi *rs)
 364 {
 365         u32 max = rx_max(rs);
 366         u32 rxw;
 367
 368         while (max--) {
 369                 rxw = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
 370                 if (rs->n_bytes == 1)
 371                         *(u8 *)(rs->rx) = (u8)rxw;
 372                 else
 373                         *(u16 *)(rs->rx) = (u16)rxw;
 374                 rs->rx += rs->n_bytes;
 375         }
 376 }
 377
 378 static int rockchip_spi_pio_transfer(struct rockchip_spi *rs)
 379 {
 380         int remain = 0;
 381
 382         do {
 383                 if (rs->tx) {
 384                         remain = rs->tx_end - rs->tx;
 385                         rockchip_spi_pio_writer(rs);
 386                 }
 387
 388                 if (rs->rx) {
 389                         remain = rs->rx_end - rs->rx;
 390                         rockchip_spi_pio_reader(rs);
 391                 }
 392
 393                 cpu_relax();
 394         } while (remain);
 395
 396         /* If tx, wait until the FIFO data completely. */
 397         if (rs->tx)
 398                 wait_for_idle(rs);
 399
 400         spi_enable_chip(rs, 0);
 401
 402         return 0;
 403 }
 404
 405 static void rockchip_spi_dma_rxcb(void *data)
 406 {
 407         unsigned long flags;
 408         struct rockchip_spi *rs = data;
 409
 410         spin_lock_irqsave(&rs->lock, flags);
 411
 412         rs->state &= ~RXBUSY;
 413         if (!(rs->state & TXBUSY)) {
 414                 spi_enable_chip(rs, 0);
 415                 spi_finalize_current_transfer(rs->master);
 416         }
 417
 418         spin_unlock_irqrestore(&rs->lock, flags);
 419 }
 420
 421 static void rockchip_spi_dma_txcb(void *data)
 422 {
 423         unsigned long flags;
 424         struct rockchip_spi *rs = data;
 425
 426         /* Wait until the FIFO data completely. */
 427         wait_for_idle(rs);
 428
 429         spin_lock_irqsave(&rs->lock, flags);
 430
 431         rs->state &= ~TXBUSY;
 432         if (!(rs->state & RXBUSY)) {
 433                 spi_enable_chip(rs, 0);
 434                 spi_finalize_current_transfer(rs->master);
 435         }
 436
 437         spin_unlock_irqrestore(&rs->lock, flags);
 438 }
 439
 440 static int rockchip_spi_prepare_dma(struct rockchip_spi *rs)
 441 {
 442         unsigned long flags;
 443         struct dma_slave_config rxconf, txconf;
 444         struct dma_async_tx_descriptor *rxdesc, *txdesc;
 445
 446         spin_lock_irqsave(&rs->lock, flags);
 447         rs->state &= ~RXBUSY;
 448         rs->state &= ~TXBUSY;
 449         spin_unlock_irqrestore(&rs->lock, flags);
 450
 451         rxdesc = NULL;
 452         if (rs->rx) {
 453                 rxconf.direction = rs->dma_rx.direction;
 454                 rxconf.src_addr = rs->dma_rx.addr;
 455                 rxconf.src_addr_width = rs->n_bytes;
 456                 if (rs->dma_caps.max_burst > 4)
 457                         rxconf.src_maxburst = 4;
 458                 else
 459                         rxconf.src_maxburst = 1;
 460                 dmaengine_slave_config(rs->dma_rx.ch, &rxconf);
 461
 462                 rxdesc = dmaengine_prep_slave_sg(
 463                                 rs->dma_rx.ch,
 464                                 rs->rx_sg.sgl, rs->rx_sg.nents,
 465                                 rs->dma_rx.direction, DMA_PREP_INTERRUPT);
 466                 if (!rxdesc)
 467                         return -EINVAL;
 468
 469                 rxdesc->callback = rockchip_spi_dma_rxcb;
 470                 rxdesc->callback_param = rs;
 471         }
 472
 473         txdesc = NULL;
 474         if (rs->tx) {
 475                 txconf.direction = rs->dma_tx.direction;
 476                 txconf.dst_addr = rs->dma_tx.addr;
 477                 txconf.dst_addr_width = rs->n_bytes;
 478                 if (rs->dma_caps.max_burst > 4)
 479                         txconf.dst_maxburst = 4;
 480                 else
 481                         txconf.dst_maxburst = 1;
 482                 dmaengine_slave_config(rs->dma_tx.ch, &txconf);
 483
 484                 txdesc = dmaengine_prep_slave_sg(
 485                                 rs->dma_tx.ch,
 486                                 rs->tx_sg.sgl, rs->tx_sg.nents,
 487                                 rs->dma_tx.direction, DMA_PREP_INTERRUPT);
 488                 if (!txdesc) {
 489                         if (rxdesc)
 490                                 dmaengine_terminate_sync(rs->dma_rx.ch);
 491                         return -EINVAL;
 492                 }
 493
 494                 txdesc->callback = rockchip_spi_dma_txcb;
 495                 txdesc->callback_param = rs;
 496         }
 497
 498         /* rx must be started before tx due to spi instinct */
 499         if (rxdesc) {
 500                 spin_lock_irqsave(&rs->lock, flags);
 501                 rs->state |= RXBUSY;
 502                 spin_unlock_irqrestore(&rs->lock, flags);
 503                 dmaengine_submit(rxdesc);
 504                 dma_async_issue_pending(rs->dma_rx.ch);
 505         }
 506
 507         if (txdesc) {
 508                 spin_lock_irqsave(&rs->lock, flags);
 509                 rs->state |= TXBUSY;
 510                 spin_unlock_irqrestore(&rs->lock, flags);
 511                 dmaengine_submit(txdesc);
 512                 dma_async_issue_pending(rs->dma_tx.ch);
 513         }
 514
 515         return 0;
 516 }
 517
 518 static void rockchip_spi_config(struct rockchip_spi *rs)
 519 {
 520         u32 div = 0;
 521         u32 dmacr = 0;
 522         int rsd = 0;
 523
 524         u32 cr0 = (CR0_BHT_8BIT << CR0_BHT_OFFSET)
 525                 | (CR0_SSD_ONE << CR0_SSD_OFFSET)
 526                 | (CR0_EM_BIG << CR0_EM_OFFSET);
 527
 528         cr0 |= (rs->n_bytes << CR0_DFS_OFFSET);
 529         cr0 |= ((rs->mode & 0x3) << CR0_SCPH_OFFSET);
 530         cr0 |= (rs->tmode << CR0_XFM_OFFSET);
 531         cr0 |= (rs->type << CR0_FRF_OFFSET);
 532
 533         if (rs->use_dma) {
 534                 if (rs->tx)
 535                         dmacr |= TF_DMA_EN;
 536                 if (rs->rx)
 537                         dmacr |= RF_DMA_EN;
 538         }
 539
 540         if (WARN_ON(rs->speed > MAX_SCLK_OUT))
 541                 rs->speed = MAX_SCLK_OUT;
 542
 543         /* the minimum divisor is 2 */
 544         if (rs->max_freq < 2 * rs->speed) {
 545                 clk_set_rate(rs->spiclk, 2 * rs->speed);
 546                 rs->max_freq = clk_get_rate(rs->spiclk);
 547         }
 548
 549         /* div doesn't support odd number */
 550         div = DIV_ROUND_UP(rs->max_freq, rs->speed);
 551         div = (div + 1) & 0xfffe;
 552
 553         /* Rx sample delay is expressed in parent clock cycles (max 3) */
 554         rsd = DIV_ROUND_CLOSEST(rs->rsd_nsecs * (rs->max_freq >> 8),
 555                                 1000000000 >> 8);
 556         if (!rsd && rs->rsd_nsecs) {
 557                 pr_warn_once("rockchip-spi: %u Hz are too slow to express %u ns delay\n",
 558                              rs->max_freq, rs->rsd_nsecs);
 559         } else if (rsd > 3) {
 560                 rsd = 3;
 561                 pr_warn_once("rockchip-spi: %u Hz are too fast to express %u ns delay, clamping at %u ns\n",
 562                              rs->max_freq, rs->rsd_nsecs,
 563                              rsd * 1000000000U / rs->max_freq);
 564         }
 565         cr0 |= rsd << CR0_RSD_OFFSET;
 566
 567         writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
 568
 569         writel_relaxed(rs->len - 1, rs->regs + ROCKCHIP_SPI_CTRLR1);
 570         writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_TXFTLR);
 571         writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
 572
 573         writel_relaxed(0, rs->regs + ROCKCHIP_SPI_DMATDLR);
 574         writel_relaxed(0, rs->regs + ROCKCHIP_SPI_DMARDLR);
 575         writel_relaxed(dmacr, rs->regs + ROCKCHIP_SPI_DMACR);
 576
 577         spi_set_clk(rs, div);
 578
 579         dev_dbg(rs->dev, "cr0 0x%x, div %d\n", cr0, div);
 580 }
 581
 582 static size_t rockchip_spi_max_transfer_size(struct spi_device *spi)
 583 {
 584         return ROCKCHIP_SPI_MAX_TRANLEN;
 585 }
 586
 587 static int rockchip_spi_transfer_one(
 588                 struct spi_master *master,
 589                 struct spi_device *spi,
 590                 struct spi_transfer *xfer)
 591 {
 592         int ret = 0;
 593         struct rockchip_spi *rs = spi_master_get_devdata(master);
 594
 595         WARN_ON(readl_relaxed(rs->regs + ROCKCHIP_SPI_SSIENR) &&
 596                 (readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY));
 597
 598         if (!xfer->tx_buf && !xfer->rx_buf) {
 599                 dev_err(rs->dev, "No buffer for transfer\n");
 600                 return -EINVAL;
 601         }
 602
 603         if (xfer->len > ROCKCHIP_SPI_MAX_TRANLEN) {
 604                 dev_err(rs->dev, "Transfer is too long (%d)\n", xfer->len);
 605                 return -EINVAL;
 606         }
 607
 608         rs->speed = xfer->speed_hz;
 609         rs->bpw = xfer->bits_per_word;
 610         rs->n_bytes = rs->bpw >> 3;
 611
 612         rs->tx = xfer->tx_buf;
 613         rs->tx_end = rs->tx + xfer->len;
 614         rs->rx = xfer->rx_buf;
 615         rs->rx_end = rs->rx + xfer->len;
 616         rs->len = xfer->len;
 617
 618         rs->tx_sg = xfer->tx_sg;
 619         rs->rx_sg = xfer->rx_sg;
 620
 621         if (rs->tx && rs->rx)
 622                 rs->tmode = CR0_XFM_TR;
 623         else if (rs->tx)
 624                 rs->tmode = CR0_XFM_TO;
 625         else if (rs->rx)
 626                 rs->tmode = CR0_XFM_RO;
 627
 628         /* we need prepare dma before spi was enabled */
 629         if (master->can_dma && master->can_dma(master, spi, xfer))
 630                 rs->use_dma = 1;
 631         else
 632                 rs->use_dma = 0;
 633
 634         rockchip_spi_config(rs);
 635
 636         if (rs->use_dma) {
 637                 if (rs->tmode == CR0_XFM_RO) {
 638                         /* rx: dma must be prepared first */
 639                         ret = rockchip_spi_prepare_dma(rs);
 640                         spi_enable_chip(rs, 1);
 641                 } else {
 642                         /* tx or tr: spi must be enabled first */
 643                         spi_enable_chip(rs, 1);
 644                         ret = rockchip_spi_prepare_dma(rs);
 645                 }
 646                 /* successful DMA prepare means the transfer is in progress */
 647                 ret = ret ? ret : 1;
 648         } else {
 649                 spi_enable_chip(rs, 1);
 650                 ret = rockchip_spi_pio_transfer(rs);
 651         }
 652
 653         return ret;
 654 }
 655
 656 static bool rockchip_spi_can_dma(struct spi_master *master,
 657                                  struct spi_device *spi,
 658                                  struct spi_transfer *xfer)
 659 {
 660         struct rockchip_spi *rs = spi_master_get_devdata(master);
 661
 662         return (xfer->len > rs->fifo_len);
 663 }
 664
 665 static int rockchip_spi_probe(struct platform_device *pdev)
 666 {
 667         int ret = 0;
 668         struct rockchip_spi *rs;
 669         struct spi_master *master;
 670         struct resource *mem;
 671         u32 rsd_nsecs;
 672
 673         master = spi_alloc_master(&pdev->dev, sizeof(struct rockchip_spi));
 674         if (!master)
 675                 return -ENOMEM;
 676
 677         platform_set_drvdata(pdev, master);
 678
 679         rs = spi_master_get_devdata(master);
 680
 681         /* Get basic io resource and map it */
 682         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 683         rs->regs = devm_ioremap_resource(&pdev->dev, mem);
 684         if (IS_ERR(rs->regs)) {
 685                 ret =  PTR_ERR(rs->regs);
 686                 goto err_ioremap_resource;
 687         }
 688
 689         rs->apb_pclk = devm_clk_get(&pdev->dev, "apb_pclk");
 690         if (IS_ERR(rs->apb_pclk)) {
 691                 dev_err(&pdev->dev, "Failed to get apb_pclk\n");
 692                 ret = PTR_ERR(rs->apb_pclk);
 693                 goto err_ioremap_resource;
 694         }
 695
 696         rs->spiclk = devm_clk_get(&pdev->dev, "spiclk");
 697         if (IS_ERR(rs->spiclk)) {
 698                 dev_err(&pdev->dev, "Failed to get spi_pclk\n");
 699                 ret = PTR_ERR(rs->spiclk);
 700                 goto err_ioremap_resource;
 701         }
 702
 703         ret = clk_prepare_enable(rs->apb_pclk);
 704         if (ret) {
 705                 dev_err(&pdev->dev, "Failed to enable apb_pclk\n");
 706                 goto err_ioremap_resource;
 707         }
 708
 709         ret = clk_prepare_enable(rs->spiclk);
 710         if (ret) {
 711                 dev_err(&pdev->dev, "Failed to enable spi_clk\n");
 712                 goto err_spiclk_enable;
 713         }
 714
 715         spi_enable_chip(rs, 0);
 716
 717         rs->type = SSI_MOTO_SPI;
 718         rs->master = master;
 719         rs->dev = &pdev->dev;
 720         rs->max_freq = clk_get_rate(rs->spiclk);
 721
 722         if (!of_property_read_u32(pdev->dev.of_node, "rx-sample-delay-ns",
 723                                   &rsd_nsecs))
 724                 rs->rsd_nsecs = rsd_nsecs;
 725
 726         rs->fifo_len = get_fifo_len(rs);
 727         if (!rs->fifo_len) {
 728                 dev_err(&pdev->dev, "Failed to get fifo length\n");
 729                 ret = -EINVAL;
 730                 goto err_get_fifo_len;
 731         }
 732
 733         spin_lock_init(&rs->lock);
 734
 735         pm_runtime_set_active(&pdev->dev);
 736         pm_runtime_enable(&pdev->dev);
 737
 738         master->auto_runtime_pm = true;
 739         master->bus_num = pdev->id;
 740         master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP;
 741         master->num_chipselect = 2;
 742         master->dev.of_node = pdev->dev.of_node;
 743         master->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8);
 744
 745         master->set_cs = rockchip_spi_set_cs;
 746         master->prepare_message = rockchip_spi_prepare_message;
 747         master->unprepare_message = rockchip_spi_unprepare_message;
 748         master->transfer_one = rockchip_spi_transfer_one;
 749         master->max_transfer_size = rockchip_spi_max_transfer_size;
 750         master->handle_err = rockchip_spi_handle_err;
 751
 752         rs->dma_tx.ch = dma_request_chan(rs->dev, "tx");
 753         if (IS_ERR(rs->dma_tx.ch)) {
 754                 /* Check tx to see if we need defer probing driver */
 755                 if (PTR_ERR(rs->dma_tx.ch) == -EPROBE_DEFER) {
 756                         ret = -EPROBE_DEFER;
 757                         goto err_get_fifo_len;
 758                 }
 759                 dev_warn(rs->dev, "Failed to request TX DMA channel\n");
 760                 rs->dma_tx.ch = NULL;
 761         }
 762
 763         rs->dma_rx.ch = dma_request_chan(rs->dev, "rx");
 764         if (IS_ERR(rs->dma_rx.ch)) {
 765                 if (PTR_ERR(rs->dma_rx.ch) == -EPROBE_DEFER) {
 766                         ret = -EPROBE_DEFER;
 767                         goto err_free_dma_tx;
 768                 }
 769                 dev_warn(rs->dev, "Failed to request RX DMA channel\n");
 770                 rs->dma_rx.ch = NULL;
 771         }
 772
 773         if (rs->dma_tx.ch && rs->dma_rx.ch) {
 774                 dma_get_slave_caps(rs->dma_rx.ch, &(rs->dma_caps));
 775                 rs->dma_tx.addr = (dma_addr_t)(mem->start + ROCKCHIP_SPI_TXDR);
 776                 rs->dma_rx.addr = (dma_addr_t)(mem->start + ROCKCHIP_SPI_RXDR);
 777                 rs->dma_tx.direction = DMA_MEM_TO_DEV;
 778                 rs->dma_rx.direction = DMA_DEV_TO_MEM;
 779
 780                 master->can_dma = rockchip_spi_can_dma;
 781                 master->dma_tx = rs->dma_tx.ch;
 782                 master->dma_rx = rs->dma_rx.ch;
 783         }
 784
 785         ret = devm_spi_register_master(&pdev->dev, master);
 786         if (ret) {
 787                 dev_err(&pdev->dev, "Failed to register master\n");
 788                 goto err_register_master;
 789         }
 790
 791         return 0;
 792
 793 err_register_master:
 794         pm_runtime_disable(&pdev->dev);
 795         if (rs->dma_rx.ch)
 796                 dma_release_channel(rs->dma_rx.ch);
 797 err_free_dma_tx:
 798         if (rs->dma_tx.ch)
 799                 dma_release_channel(rs->dma_tx.ch);
 800 err_get_fifo_len:
 801         clk_disable_unprepare(rs->spiclk);
 802 err_spiclk_enable:
 803         clk_disable_unprepare(rs->apb_pclk);
 804 err_ioremap_resource:
 805         spi_master_put(master);
 806
 807         return ret;
 808 }
 809
 810 static int rockchip_spi_remove(struct platform_device *pdev)
 811 {
 812         struct spi_master *master = spi_master_get(platform_get_drvdata(pdev));
 813         struct rockchip_spi *rs = spi_master_get_devdata(master);
 814
 815         pm_runtime_disable(&pdev->dev);
 816
 817         clk_disable_unprepare(rs->spiclk);
 818         clk_disable_unprepare(rs->apb_pclk);
 819
 820         if (rs->dma_tx.ch)
 821                 dma_release_channel(rs->dma_tx.ch);
 822         if (rs->dma_rx.ch)
 823                 dma_release_channel(rs->dma_rx.ch);
 824
 825         spi_master_put(master);
 826
 827         return 0;
 828 }
 829
 830 #ifdef CONFIG_PM_SLEEP
 831 static int rockchip_spi_suspend(struct device *dev)
 832 {
 833         int ret = 0;
 834         struct spi_master *master = dev_get_drvdata(dev);
 835         struct rockchip_spi *rs = spi_master_get_devdata(master);
 836
 837         ret = spi_master_suspend(rs->master);
 838         if (ret)
 839                 return ret;
 840
 841         if (!pm_runtime_suspended(dev)) {
 842                 clk_disable_unprepare(rs->spiclk);
 843                 clk_disable_unprepare(rs->apb_pclk);
 844         }
 845
 846         return ret;
 847 }
 848
 849 static int rockchip_spi_resume(struct device *dev)
 850 {
 851         int ret = 0;
 852         struct spi_master *master = dev_get_drvdata(dev);
 853         struct rockchip_spi *rs = spi_master_get_devdata(master);
 854
 855         if (!pm_runtime_suspended(dev)) {
 856                 ret = clk_prepare_enable(rs->apb_pclk);
 857                 if (ret < 0)
 858                         return ret;
 859
 860                 ret = clk_prepare_enable(rs->spiclk);
 861                 if (ret < 0) {
 862                         clk_disable_unprepare(rs->apb_pclk);
 863                         return ret;
 864                 }
 865         }
 866
 867         ret = spi_master_resume(rs->master);
 868         if (ret < 0) {
 869                 clk_disable_unprepare(rs->spiclk);
 870                 clk_disable_unprepare(rs->apb_pclk);
 871         }
 872
 873         return ret;
 874 }
 875 #endif /* CONFIG_PM_SLEEP */
 876
 877 #ifdef CONFIG_PM
 878 static int rockchip_spi_runtime_suspend(struct device *dev)
 879 {
 880         struct spi_master *master = dev_get_drvdata(dev);
 881         struct rockchip_spi *rs = spi_master_get_devdata(master);
 882
 883         clk_disable_unprepare(rs->spiclk);
 884         clk_disable_unprepare(rs->apb_pclk);
 885
 886         return 0;
 887 }
 888
 889 static int rockchip_spi_runtime_resume(struct device *dev)
 890 {
 891         int ret;
 892         struct spi_master *master = dev_get_drvdata(dev);
 893         struct rockchip_spi *rs = spi_master_get_devdata(master);
 894
 895         ret = clk_prepare_enable(rs->apb_pclk);
 896         if (ret)
 897                 return ret;
 898
 899         ret = clk_prepare_enable(rs->spiclk);
 900         if (ret)
 901                 clk_disable_unprepare(rs->apb_pclk);
 902
 903         return ret;
 904 }
 905 #endif /* CONFIG_PM */
 906
 907 static const struct dev_pm_ops rockchip_spi_pm = {
 908         SET_SYSTEM_SLEEP_PM_OPS(rockchip_spi_suspend, rockchip_spi_resume)
 909         SET_RUNTIME_PM_OPS(rockchip_spi_runtime_suspend,
 910                            rockchip_spi_runtime_resume, NULL)
 911 };
 912
 913 static const struct of_device_id rockchip_spi_dt_match[] = {
 914         { .compatible = "rockchip,rk3036-spi", },
 915         { .compatible = "rockchip,rk3066-spi", },
 916         { .compatible = "rockchip,rk3188-spi", },
 917         { .compatible = "rockchip,rk3228-spi", },
 918         { .compatible = "rockchip,rk3288-spi", },
 919         { .compatible = "rockchip,rk3368-spi", },
 920         { .compatible = "rockchip,rk3399-spi", },
 921         { },
 922 };
 923 MODULE_DEVICE_TABLE(of, rockchip_spi_dt_match);
 924
 925 static struct platform_driver rockchip_spi_driver = {
 926         .driver = {
 927                 .name   = DRIVER_NAME,
 928                 .pm = &rockchip_spi_pm,
 929                 .of_match_table = of_match_ptr(rockchip_spi_dt_match),
 930         },
 931         .probe = rockchip_spi_probe,
 932         .remove = rockchip_spi_remove,
 933 };
 934
 935 module_platform_driver(rockchip_spi_driver);
 936
 937 MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
 938 MODULE_DESCRIPTION("ROCKCHIP SPI Controller Driver");
 939 MODULE_LICENSE("GPL v2");