drivers/usb/serial/f81232.c

   1 /*
   2  * Fintek F81232 USB to serial adaptor driver
   3  *
   4  * Copyright (C) 2012 Greg Kroah-Hartman (gregkh@linuxfoundation.org)
   5  * Copyright (C) 2012 Linux Foundation
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License version 2 as published by
   9  * the Free Software Foundation.
  10  *
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/errno.h>
  15 #include <linux/init.h>
  16 #include <linux/slab.h>
  17 #include <linux/tty.h>
  18 #include <linux/tty_driver.h>
  19 #include <linux/tty_flip.h>
  20 #include <linux/serial.h>
  21 #include <linux/module.h>
  22 #include <linux/moduleparam.h>
  23 #include <linux/spinlock.h>
  24 #include <linux/uaccess.h>
  25 #include <linux/usb.h>
  26 #include <linux/usb/serial.h>
  27
  28 static const struct usb_device_id id_table[] = {
  29         { USB_DEVICE(0x1934, 0x0706) },
  30         { }                                     /* Terminating entry */
  31 };
  32 MODULE_DEVICE_TABLE(usb, id_table);
  33
  34 #define CONTROL_DTR                     0x01
  35 #define CONTROL_RTS                     0x02
  36
  37 #define UART_STATE                      0x08
  38 #define UART_STATE_TRANSIENT_MASK       0x74
  39 #define UART_DCD                        0x01
  40 #define UART_DSR                        0x02
  41 #define UART_BREAK_ERROR                0x04
  42 #define UART_RING                       0x08
  43 #define UART_FRAME_ERROR                0x10
  44 #define UART_PARITY_ERROR               0x20
  45 #define UART_OVERRUN_ERROR              0x40
  46 #define UART_CTS                        0x80
  47
  48 struct f81232_private {
  49         spinlock_t lock;
  50         wait_queue_head_t delta_msr_wait;
  51         u8 line_control;
  52         u8 line_status;
  53 };
  54
  55 static void f81232_update_line_status(struct usb_serial_port *port,
  56                                       unsigned char *data,
  57                                       unsigned int actual_length)
  58 {
  59 }
  60
  61 static void f81232_read_int_callback(struct urb *urb)
  62 {
  63         struct usb_serial_port *port =  urb->context;
  64         unsigned char *data = urb->transfer_buffer;
  65         unsigned int actual_length = urb->actual_length;
  66         int status = urb->status;
  67         int retval;
  68
  69         switch (status) {
  70         case 0:
  71                 /* success */
  72                 break;
  73         case -ECONNRESET:
  74         case -ENOENT:
  75         case -ESHUTDOWN:
  76                 /* this urb is terminated, clean up */
  77                 dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
  78                         __func__, status);
  79                 return;
  80         default:
  81                 dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
  82                         __func__, status);
  83                 goto exit;
  84         }
  85
  86         usb_serial_debug_data(&port->dev, __func__,
  87                               urb->actual_length, urb->transfer_buffer);
  88
  89         f81232_update_line_status(port, data, actual_length);
  90
  91 exit:
  92         retval = usb_submit_urb(urb, GFP_ATOMIC);
  93         if (retval)
  94                 dev_err(&urb->dev->dev,
  95                         "%s - usb_submit_urb failed with result %d\n",
  96                         __func__, retval);
  97 }
  98
  99 static void f81232_process_read_urb(struct urb *urb)
 100 {
 101         struct usb_serial_port *port = urb->context;
 102         struct f81232_private *priv = usb_get_serial_port_data(port);
 103         struct tty_struct *tty;
 104         unsigned char *data = urb->transfer_buffer;
 105         char tty_flag = TTY_NORMAL;
 106         unsigned long flags;
 107         u8 line_status;
 108         int i;
 109
 110         /* update line status */
 111         spin_lock_irqsave(&priv->lock, flags);
 112         line_status = priv->line_status;
 113         priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
 114         spin_unlock_irqrestore(&priv->lock, flags);
 115         wake_up_interruptible(&priv->delta_msr_wait);
 116
 117         if (!urb->actual_length)
 118                 return;
 119
 120         tty = tty_port_tty_get(&port->port);
 121         if (!tty)
 122                 return;
 123
 124         /* break takes precedence over parity, */
 125         /* which takes precedence over framing errors */
 126         if (line_status & UART_BREAK_ERROR)
 127                 tty_flag = TTY_BREAK;
 128         else if (line_status & UART_PARITY_ERROR)
 129                 tty_flag = TTY_PARITY;
 130         else if (line_status & UART_FRAME_ERROR)
 131                 tty_flag = TTY_FRAME;
 132         dev_dbg(&port->dev, "%s - tty_flag = %d\n", __func__, tty_flag);
 133
 134         /* overrun is special, not associated with a char */
 135         if (line_status & UART_OVERRUN_ERROR)
 136                 tty_insert_flip_char(tty, 0, TTY_OVERRUN);
 137
 138         if (port->port.console && port->sysrq) {
 139                 for (i = 0; i < urb->actual_length; ++i)
 140                         if (!usb_serial_handle_sysrq_char(port, data[i]))
 141                                 tty_insert_flip_char(tty, data[i], tty_flag);
 142         } else {
 143                 tty_insert_flip_string_fixed_flag(tty, data, tty_flag,
 144                                                         urb->actual_length);
 145         }
 146
 147         tty_flip_buffer_push(tty);
 148         tty_kref_put(tty);
 149 }
 150
 151 static int set_control_lines(struct usb_device *dev, u8 value)
 152 {
 153         /* FIXME - Stubbed out for now */
 154         return 0;
 155 }
 156
 157 static void f81232_break_ctl(struct tty_struct *tty, int break_state)
 158 {
 159         /* FIXME - Stubbed out for now */
 160
 161         /*
 162          * break_state = -1 to turn on break, and 0 to turn off break
 163          * see drivers/char/tty_io.c to see it used.
 164          * last_set_data_urb_value NEVER has the break bit set in it.
 165          */
 166 }
 167
 168 static void f81232_set_termios(struct tty_struct *tty,
 169                 struct usb_serial_port *port, struct ktermios *old_termios)
 170 {
 171         /* FIXME - Stubbed out for now */
 172
 173         /* Don't change anything if nothing has changed */
 174         if (!tty_termios_hw_change(&tty->termios, old_termios))
 175                 return;
 176
 177         /* Do the real work here... */
 178         tty_termios_copy_hw(&tty->termios, old_termios);
 179 }
 180
 181 static int f81232_tiocmget(struct tty_struct *tty)
 182 {
 183         /* FIXME - Stubbed out for now */
 184         return 0;
 185 }
 186
 187 static int f81232_tiocmset(struct tty_struct *tty,
 188                         unsigned int set, unsigned int clear)
 189 {
 190         /* FIXME - Stubbed out for now */
 191         return 0;
 192 }
 193
 194 static int f81232_open(struct tty_struct *tty, struct usb_serial_port *port)
 195 {
 196         struct ktermios tmp_termios;
 197         int result;
 198
 199         /* Setup termios */
 200         if (tty)
 201                 f81232_set_termios(tty, port, &tmp_termios);
 202
 203         result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
 204         if (result) {
 205                 dev_err(&port->dev, "%s - failed submitting interrupt urb,"
 206                         " error %d\n", __func__, result);
 207                 return result;
 208         }
 209
 210         result = usb_serial_generic_open(tty, port);
 211         if (result) {
 212                 usb_kill_urb(port->interrupt_in_urb);
 213                 return result;
 214         }
 215
 216         port->port.drain_delay = 256;
 217         return 0;
 218 }
 219
 220 static void f81232_close(struct usb_serial_port *port)
 221 {
 222         usb_serial_generic_close(port);
 223         usb_kill_urb(port->interrupt_in_urb);
 224 }
 225
 226 static void f81232_dtr_rts(struct usb_serial_port *port, int on)
 227 {
 228         struct f81232_private *priv = usb_get_serial_port_data(port);
 229         unsigned long flags;
 230         u8 control;
 231
 232         spin_lock_irqsave(&priv->lock, flags);
 233         /* Change DTR and RTS */
 234         if (on)
 235                 priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
 236         else
 237                 priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
 238         control = priv->line_control;
 239         spin_unlock_irqrestore(&priv->lock, flags);
 240         set_control_lines(port->serial->dev, control);
 241 }
 242
 243 static int f81232_carrier_raised(struct usb_serial_port *port)
 244 {
 245         struct f81232_private *priv = usb_get_serial_port_data(port);
 246         if (priv->line_status & UART_DCD)
 247                 return 1;
 248         return 0;
 249 }
 250
 251 static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
 252 {
 253         struct f81232_private *priv = usb_get_serial_port_data(port);
 254         unsigned long flags;
 255         unsigned int prevstatus;
 256         unsigned int status;
 257         unsigned int changed;
 258
 259         spin_lock_irqsave(&priv->lock, flags);
 260         prevstatus = priv->line_status;
 261         spin_unlock_irqrestore(&priv->lock, flags);
 262
 263         while (1) {
 264                 interruptible_sleep_on(&priv->delta_msr_wait);
 265                 /* see if a signal did it */
 266                 if (signal_pending(current))
 267                         return -ERESTARTSYS;
 268
 269                 spin_lock_irqsave(&priv->lock, flags);
 270                 status = priv->line_status;
 271                 spin_unlock_irqrestore(&priv->lock, flags);
 272
 273                 changed = prevstatus ^ status;
 274
 275                 if (((arg & TIOCM_RNG) && (changed & UART_RING)) ||
 276                     ((arg & TIOCM_DSR) && (changed & UART_DSR)) ||
 277                     ((arg & TIOCM_CD)  && (changed & UART_DCD)) ||
 278                     ((arg & TIOCM_CTS) && (changed & UART_CTS))) {
 279                         return 0;
 280                 }
 281                 prevstatus = status;
 282         }
 283         /* NOTREACHED */
 284         return 0;
 285 }
 286
 287 static int f81232_ioctl(struct tty_struct *tty,
 288                         unsigned int cmd, unsigned long arg)
 289 {
 290         struct serial_struct ser;
 291         struct usb_serial_port *port = tty->driver_data;
 292
 293         dev_dbg(&port->dev, "%s (%d) cmd = 0x%04x\n", __func__,
 294                 port->number, cmd);
 295
 296         switch (cmd) {
 297         case TIOCGSERIAL:
 298                 memset(&ser, 0, sizeof ser);
 299                 ser.type = PORT_16654;
 300                 ser.line = port->serial->minor;
 301                 ser.port = port->number;
 302                 ser.baud_base = 460800;
 303
 304                 if (copy_to_user((void __user *)arg, &ser, sizeof ser))
 305                         return -EFAULT;
 306
 307                 return 0;
 308
 309         case TIOCMIWAIT:
 310                 dev_dbg(&port->dev, "%s (%d) TIOCMIWAIT\n", __func__,
 311                         port->number);
 312                 return wait_modem_info(port, arg);
 313         default:
 314                 dev_dbg(&port->dev, "%s not supported = 0x%04x\n",
 315                         __func__, cmd);
 316                 break;
 317         }
 318         return -ENOIOCTLCMD;
 319 }
 320
 321 static int f81232_port_probe(struct usb_serial_port *port)
 322 {
 323         struct f81232_private *priv;
 324
 325         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 326         if (!priv)
 327                 return -ENOMEM;
 328
 329         spin_lock_init(&priv->lock);
 330         init_waitqueue_head(&priv->delta_msr_wait);
 331
 332         usb_set_serial_port_data(port, priv);
 333
 334         return 0;
 335 }
 336
 337 static int f81232_port_remove(struct usb_serial_port *port)
 338 {
 339         struct f81232_private *priv;
 340
 341         priv = usb_get_serial_port_data(port);
 342         kfree(priv);
 343
 344         return 0;
 345 }
 346
 347 static struct usb_serial_driver f81232_device = {
 348         .driver = {
 349                 .owner =        THIS_MODULE,
 350                 .name =         "f81232",
 351         },
 352         .id_table =             id_table,
 353         .num_ports =            1,
 354         .bulk_in_size =         256,
 355         .bulk_out_size =        256,
 356         .open =                 f81232_open,
 357         .close =                f81232_close,
 358         .dtr_rts =              f81232_dtr_rts,
 359         .carrier_raised =       f81232_carrier_raised,
 360         .ioctl =                f81232_ioctl,
 361         .break_ctl =            f81232_break_ctl,
 362         .set_termios =          f81232_set_termios,
 363         .tiocmget =             f81232_tiocmget,
 364         .tiocmset =             f81232_tiocmset,
 365         .process_read_urb =     f81232_process_read_urb,
 366         .read_int_callback =    f81232_read_int_callback,
 367         .port_probe =           f81232_port_probe,
 368         .port_remove =          f81232_port_remove,
 369 };
 370
 371 static struct usb_serial_driver * const serial_drivers[] = {
 372         &f81232_device,
 373         NULL,
 374 };
 375
 376 module_usb_serial_driver(serial_drivers, id_table);
 377
 378 MODULE_DESCRIPTION("Fintek F81232 USB to serial adaptor driver");
 379 MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org");
 380 MODULE_LICENSE("GPL v2");