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/slab.h>
  16 #include <linux/tty.h>
  17 #include <linux/tty_driver.h>
  18 #include <linux/tty_flip.h>
  19 #include <linux/serial.h>
  20 #include <linux/module.h>
  21 #include <linux/moduleparam.h>
  22 #include <linux/mutex.h>
  23 #include <linux/uaccess.h>
  24 #include <linux/usb.h>
  25 #include <linux/usb/serial.h>
  26 #include <linux/serial_reg.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 /* USB Control EP parameter */
  35 #define F81232_REGISTER_REQUEST 0xa0
  36 #define F81232_GET_REGISTER             0xc0
  37
  38 #define SERIAL_BASE_ADDRESS                     0x0120
  39 #define MODEM_STATUS_REGISTER           (0x06 + SERIAL_BASE_ADDRESS)
  40
  41 #define CONTROL_DTR                     0x01
  42 #define CONTROL_RTS                     0x02
  43
  44 #define UART_STATE                      0x08
  45 #define UART_STATE_TRANSIENT_MASK       0x74
  46 #define UART_DCD                        0x01
  47 #define UART_DSR                        0x02
  48 #define UART_BREAK_ERROR                0x04
  49 #define UART_RING                       0x08
  50 #define UART_FRAME_ERROR                0x10
  51 #define UART_PARITY_ERROR               0x20
  52 #define UART_OVERRUN_ERROR              0x40
  53 #define UART_CTS                        0x80
  54
  55 struct f81232_private {
  56         struct mutex lock;
  57         u8 line_control;
  58         u8 modem_status;
  59         struct work_struct interrupt_work;
  60         struct usb_serial_port *port;
  61 };
  62
  63 static int f81232_get_register(struct usb_serial_port *port, u16 reg, u8 *val)
  64 {
  65         int status;
  66         u8 *tmp;
  67         struct usb_device *dev = port->serial->dev;
  68
  69         tmp = kmalloc(sizeof(*val), GFP_KERNEL);
  70         if (!tmp)
  71                 return -ENOMEM;
  72
  73         status = usb_control_msg(dev,
  74                                 usb_rcvctrlpipe(dev, 0),
  75                                 F81232_REGISTER_REQUEST,
  76                                 F81232_GET_REGISTER,
  77                                 reg,
  78                                 0,
  79                                 tmp,
  80                                 sizeof(*val),
  81                                 USB_CTRL_GET_TIMEOUT);
  82         if (status != sizeof(*val)) {
  83                 dev_err(&port->dev, "%s failed status: %d\n", __func__, status);
  84
  85                 if (status < 0)
  86                         status = usb_translate_errors(status);
  87                 else
  88                         status = -EIO;
  89         } else {
  90                 status = 0;
  91                 *val = *tmp;
  92         }
  93
  94         kfree(tmp);
  95         return status;
  96 }
  97
  98 static void f81232_read_msr(struct usb_serial_port *port)
  99 {
 100         int status;
 101         u8 current_msr;
 102         struct tty_struct *tty;
 103         struct f81232_private *priv = usb_get_serial_port_data(port);
 104
 105         mutex_lock(&priv->lock);
 106         status = f81232_get_register(port, MODEM_STATUS_REGISTER,
 107                         &current_msr);
 108         if (status) {
 109                 dev_err(&port->dev, "%s fail, status: %d\n", __func__, status);
 110                 mutex_unlock(&priv->lock);
 111                 return;
 112         }
 113
 114         if (!(current_msr & UART_MSR_ANY_DELTA)) {
 115                 mutex_unlock(&priv->lock);
 116                 return;
 117         }
 118
 119         priv->modem_status = current_msr;
 120
 121         if (current_msr & UART_MSR_DCTS)
 122                 port->icount.cts++;
 123         if (current_msr & UART_MSR_DDSR)
 124                 port->icount.dsr++;
 125         if (current_msr & UART_MSR_TERI)
 126                 port->icount.rng++;
 127         if (current_msr & UART_MSR_DDCD) {
 128                 port->icount.dcd++;
 129                 tty = tty_port_tty_get(&port->port);
 130                 if (tty) {
 131                         usb_serial_handle_dcd_change(port, tty,
 132                                         current_msr & UART_MSR_DCD);
 133
 134                         tty_kref_put(tty);
 135                 }
 136         }
 137
 138         wake_up_interruptible(&port->port.delta_msr_wait);
 139         mutex_unlock(&priv->lock);
 140 }
 141
 142 static void f81232_update_line_status(struct usb_serial_port *port,
 143                                       unsigned char *data,
 144                                       size_t actual_length)
 145 {
 146         struct f81232_private *priv = usb_get_serial_port_data(port);
 147
 148         if (!actual_length)
 149                 return;
 150
 151         switch (data[0] & 0x07) {
 152         case 0x00: /* msr change */
 153                 dev_dbg(&port->dev, "IIR: MSR Change: %02x\n", data[0]);
 154                 schedule_work(&priv->interrupt_work);
 155                 break;
 156         case 0x02: /* tx-empty */
 157                 break;
 158         case 0x04: /* rx data available */
 159                 break;
 160         case 0x06: /* lsr change */
 161                 /* we can forget it. the LSR will read from bulk-in */
 162                 dev_dbg(&port->dev, "IIR: LSR Change: %02x\n", data[0]);
 163                 break;
 164         }
 165 }
 166
 167 static void f81232_read_int_callback(struct urb *urb)
 168 {
 169         struct usb_serial_port *port =  urb->context;
 170         unsigned char *data = urb->transfer_buffer;
 171         unsigned int actual_length = urb->actual_length;
 172         int status = urb->status;
 173         int retval;
 174
 175         switch (status) {
 176         case 0:
 177                 /* success */
 178                 break;
 179         case -ECONNRESET:
 180         case -ENOENT:
 181         case -ESHUTDOWN:
 182                 /* this urb is terminated, clean up */
 183                 dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
 184                         __func__, status);
 185                 return;
 186         default:
 187                 dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
 188                         __func__, status);
 189                 goto exit;
 190         }
 191
 192         usb_serial_debug_data(&port->dev, __func__,
 193                               urb->actual_length, urb->transfer_buffer);
 194
 195         f81232_update_line_status(port, data, actual_length);
 196
 197 exit:
 198         retval = usb_submit_urb(urb, GFP_ATOMIC);
 199         if (retval)
 200                 dev_err(&urb->dev->dev,
 201                         "%s - usb_submit_urb failed with result %d\n",
 202                         __func__, retval);
 203 }
 204
 205 static void f81232_process_read_urb(struct urb *urb)
 206 {
 207         struct usb_serial_port *port = urb->context;
 208         unsigned char *data = urb->transfer_buffer;
 209         char tty_flag;
 210         unsigned int i;
 211         u8 lsr;
 212
 213         /*
 214          * When opening the port we get a 1-byte packet with the current LSR,
 215          * which we discard.
 216          */
 217         if ((urb->actual_length < 2) || (urb->actual_length % 2))
 218                 return;
 219
 220         /* bulk-in data: [LSR(1Byte)+DATA(1Byte)][LSR(1Byte)+DATA(1Byte)]... */
 221
 222         for (i = 0; i < urb->actual_length; i += 2) {
 223                 tty_flag = TTY_NORMAL;
 224                 lsr = data[i];
 225
 226                 if (lsr & UART_LSR_BRK_ERROR_BITS) {
 227                         if (lsr & UART_LSR_BI) {
 228                                 tty_flag = TTY_BREAK;
 229                                 port->icount.brk++;
 230                                 usb_serial_handle_break(port);
 231                         } else if (lsr & UART_LSR_PE) {
 232                                 tty_flag = TTY_PARITY;
 233                                 port->icount.parity++;
 234                         } else if (lsr & UART_LSR_FE) {
 235                                 tty_flag = TTY_FRAME;
 236                                 port->icount.frame++;
 237                         }
 238
 239                         if (lsr & UART_LSR_OE) {
 240                                 port->icount.overrun++;
 241                                 tty_insert_flip_char(&port->port, 0,
 242                                                 TTY_OVERRUN);
 243                         }
 244                 }
 245
 246                 if (port->port.console && port->sysrq) {
 247                         if (usb_serial_handle_sysrq_char(port, data[i + 1]))
 248                                 continue;
 249                 }
 250
 251                 tty_insert_flip_char(&port->port, data[i + 1], tty_flag);
 252         }
 253
 254         tty_flip_buffer_push(&port->port);
 255 }
 256
 257 static int set_control_lines(struct usb_device *dev, u8 value)
 258 {
 259         /* FIXME - Stubbed out for now */
 260         return 0;
 261 }
 262
 263 static void f81232_break_ctl(struct tty_struct *tty, int break_state)
 264 {
 265         /* FIXME - Stubbed out for now */
 266
 267         /*
 268          * break_state = -1 to turn on break, and 0 to turn off break
 269          * see drivers/char/tty_io.c to see it used.
 270          * last_set_data_urb_value NEVER has the break bit set in it.
 271          */
 272 }
 273
 274 static void f81232_set_termios(struct tty_struct *tty,
 275                 struct usb_serial_port *port, struct ktermios *old_termios)
 276 {
 277         /* FIXME - Stubbed out for now */
 278
 279         /* Don't change anything if nothing has changed */
 280         if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
 281                 return;
 282
 283         /* Do the real work here... */
 284         if (old_termios)
 285                 tty_termios_copy_hw(&tty->termios, old_termios);
 286 }
 287
 288 static int f81232_tiocmget(struct tty_struct *tty)
 289 {
 290         /* FIXME - Stubbed out for now */
 291         return 0;
 292 }
 293
 294 static int f81232_tiocmset(struct tty_struct *tty,
 295                         unsigned int set, unsigned int clear)
 296 {
 297         /* FIXME - Stubbed out for now */
 298         return 0;
 299 }
 300
 301 static int f81232_open(struct tty_struct *tty, struct usb_serial_port *port)
 302 {
 303         int result;
 304
 305         /* Setup termios */
 306         if (tty)
 307                 f81232_set_termios(tty, port, NULL);
 308
 309         result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
 310         if (result) {
 311                 dev_err(&port->dev, "%s - failed submitting interrupt urb,"
 312                         " error %d\n", __func__, result);
 313                 return result;
 314         }
 315
 316         result = usb_serial_generic_open(tty, port);
 317         if (result) {
 318                 usb_kill_urb(port->interrupt_in_urb);
 319                 return result;
 320         }
 321
 322         return 0;
 323 }
 324
 325 static void f81232_close(struct usb_serial_port *port)
 326 {
 327         usb_serial_generic_close(port);
 328         usb_kill_urb(port->interrupt_in_urb);
 329 }
 330
 331 static void f81232_dtr_rts(struct usb_serial_port *port, int on)
 332 {
 333         struct f81232_private *priv = usb_get_serial_port_data(port);
 334         u8 control;
 335
 336         mutex_lock(&priv->lock);
 337         /* Change DTR and RTS */
 338         if (on)
 339                 priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
 340         else
 341                 priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
 342         control = priv->line_control;
 343         mutex_unlock(&priv->lock);
 344         set_control_lines(port->serial->dev, control);
 345 }
 346
 347 static int f81232_carrier_raised(struct usb_serial_port *port)
 348 {
 349         struct f81232_private *priv = usb_get_serial_port_data(port);
 350         if (priv->modem_status & UART_DCD)
 351                 return 1;
 352         return 0;
 353 }
 354
 355 static int f81232_ioctl(struct tty_struct *tty,
 356                         unsigned int cmd, unsigned long arg)
 357 {
 358         struct serial_struct ser;
 359         struct usb_serial_port *port = tty->driver_data;
 360
 361         switch (cmd) {
 362         case TIOCGSERIAL:
 363                 memset(&ser, 0, sizeof ser);
 364                 ser.type = PORT_16654;
 365                 ser.line = port->minor;
 366                 ser.port = port->port_number;
 367                 ser.baud_base = 460800;
 368
 369                 if (copy_to_user((void __user *)arg, &ser, sizeof ser))
 370                         return -EFAULT;
 371
 372                 return 0;
 373         default:
 374                 break;
 375         }
 376         return -ENOIOCTLCMD;
 377 }
 378
 379 static void  f81232_interrupt_work(struct work_struct *work)
 380 {
 381         struct f81232_private *priv =
 382                 container_of(work, struct f81232_private, interrupt_work);
 383
 384         f81232_read_msr(priv->port);
 385 }
 386
 387 static int f81232_port_probe(struct usb_serial_port *port)
 388 {
 389         struct f81232_private *priv;
 390
 391         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 392         if (!priv)
 393                 return -ENOMEM;
 394
 395         mutex_init(&priv->lock);
 396         INIT_WORK(&priv->interrupt_work,  f81232_interrupt_work);
 397
 398         usb_set_serial_port_data(port, priv);
 399
 400         port->port.drain_delay = 256;
 401         priv->port = port;
 402
 403         return 0;
 404 }
 405
 406 static int f81232_port_remove(struct usb_serial_port *port)
 407 {
 408         struct f81232_private *priv;
 409
 410         priv = usb_get_serial_port_data(port);
 411         kfree(priv);
 412
 413         return 0;
 414 }
 415
 416 static struct usb_serial_driver f81232_device = {
 417         .driver = {
 418                 .owner =        THIS_MODULE,
 419                 .name =         "f81232",
 420         },
 421         .id_table =             id_table,
 422         .num_ports =            1,
 423         .bulk_in_size =         256,
 424         .bulk_out_size =        256,
 425         .open =                 f81232_open,
 426         .close =                f81232_close,
 427         .dtr_rts =              f81232_dtr_rts,
 428         .carrier_raised =       f81232_carrier_raised,
 429         .ioctl =                f81232_ioctl,
 430         .break_ctl =            f81232_break_ctl,
 431         .set_termios =          f81232_set_termios,
 432         .tiocmget =             f81232_tiocmget,
 433         .tiocmset =             f81232_tiocmset,
 434         .tiocmiwait =           usb_serial_generic_tiocmiwait,
 435         .process_read_urb =     f81232_process_read_urb,
 436         .read_int_callback =    f81232_read_int_callback,
 437         .port_probe =           f81232_port_probe,
 438         .port_remove =          f81232_port_remove,
 439 };
 440
 441 static struct usb_serial_driver * const serial_drivers[] = {
 442         &f81232_device,
 443         NULL,
 444 };
 445
 446 module_usb_serial_driver(serial_drivers, id_table);
 447
 448 MODULE_DESCRIPTION("Fintek F81232 USB to serial adaptor driver");
 449 MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org");
 450 MODULE_LICENSE("GPL v2");