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         unsigned char *data = urb->transfer_buffer;
 104         char tty_flag = TTY_NORMAL;
 105         unsigned long flags;
 106         u8 line_status;
 107         int i;
 108
 109         /* update line status */
 110         spin_lock_irqsave(&priv->lock, flags);
 111         line_status = priv->line_status;
 112         priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
 113         spin_unlock_irqrestore(&priv->lock, flags);
 114         wake_up_interruptible(&priv->delta_msr_wait);
 115
 116         if (!urb->actual_length)
 117                 return;
 118
 119         /* break takes precedence over parity, */
 120         /* which takes precedence over framing errors */
 121         if (line_status & UART_BREAK_ERROR)
 122                 tty_flag = TTY_BREAK;
 123         else if (line_status & UART_PARITY_ERROR)
 124                 tty_flag = TTY_PARITY;
 125         else if (line_status & UART_FRAME_ERROR)
 126                 tty_flag = TTY_FRAME;
 127         dev_dbg(&port->dev, "%s - tty_flag = %d\n", __func__, tty_flag);
 128
 129         /* overrun is special, not associated with a char */
 130         if (line_status & UART_OVERRUN_ERROR)
 131                 tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
 132
 133         if (port->port.console && port->sysrq) {
 134                 for (i = 0; i < urb->actual_length; ++i)
 135                         if (!usb_serial_handle_sysrq_char(port, data[i]))
 136                                 tty_insert_flip_char(&port->port, data[i],
 137                                                 tty_flag);
 138         } else {
 139                 tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
 140                                                         urb->actual_length);
 141         }
 142
 143         tty_flip_buffer_push(&port->port);
 144 }
 145
 146 static int set_control_lines(struct usb_device *dev, u8 value)
 147 {
 148         /* FIXME - Stubbed out for now */
 149         return 0;
 150 }
 151
 152 static void f81232_break_ctl(struct tty_struct *tty, int break_state)
 153 {
 154         /* FIXME - Stubbed out for now */
 155
 156         /*
 157          * break_state = -1 to turn on break, and 0 to turn off break
 158          * see drivers/char/tty_io.c to see it used.
 159          * last_set_data_urb_value NEVER has the break bit set in it.
 160          */
 161 }
 162
 163 static void f81232_set_termios(struct tty_struct *tty,
 164                 struct usb_serial_port *port, struct ktermios *old_termios)
 165 {
 166         /* FIXME - Stubbed out for now */
 167
 168         /* Don't change anything if nothing has changed */
 169         if (!tty_termios_hw_change(&tty->termios, old_termios))
 170                 return;
 171
 172         /* Do the real work here... */
 173         tty_termios_copy_hw(&tty->termios, old_termios);
 174 }
 175
 176 static int f81232_tiocmget(struct tty_struct *tty)
 177 {
 178         /* FIXME - Stubbed out for now */
 179         return 0;
 180 }
 181
 182 static int f81232_tiocmset(struct tty_struct *tty,
 183                         unsigned int set, unsigned int clear)
 184 {
 185         /* FIXME - Stubbed out for now */
 186         return 0;
 187 }
 188
 189 static int f81232_open(struct tty_struct *tty, struct usb_serial_port *port)
 190 {
 191         struct ktermios tmp_termios;
 192         int result;
 193
 194         /* Setup termios */
 195         if (tty)
 196                 f81232_set_termios(tty, port, &tmp_termios);
 197
 198         result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
 199         if (result) {
 200                 dev_err(&port->dev, "%s - failed submitting interrupt urb,"
 201                         " error %d\n", __func__, result);
 202                 return result;
 203         }
 204
 205         result = usb_serial_generic_open(tty, port);
 206         if (result) {
 207                 usb_kill_urb(port->interrupt_in_urb);
 208                 return result;
 209         }
 210
 211         port->port.drain_delay = 256;
 212         return 0;
 213 }
 214
 215 static void f81232_close(struct usb_serial_port *port)
 216 {
 217         usb_serial_generic_close(port);
 218         usb_kill_urb(port->interrupt_in_urb);
 219 }
 220
 221 static void f81232_dtr_rts(struct usb_serial_port *port, int on)
 222 {
 223         struct f81232_private *priv = usb_get_serial_port_data(port);
 224         unsigned long flags;
 225         u8 control;
 226
 227         spin_lock_irqsave(&priv->lock, flags);
 228         /* Change DTR and RTS */
 229         if (on)
 230                 priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
 231         else
 232                 priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
 233         control = priv->line_control;
 234         spin_unlock_irqrestore(&priv->lock, flags);
 235         set_control_lines(port->serial->dev, control);
 236 }
 237
 238 static int f81232_carrier_raised(struct usb_serial_port *port)
 239 {
 240         struct f81232_private *priv = usb_get_serial_port_data(port);
 241         if (priv->line_status & UART_DCD)
 242                 return 1;
 243         return 0;
 244 }
 245
 246 static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
 247 {
 248         struct f81232_private *priv = usb_get_serial_port_data(port);
 249         unsigned long flags;
 250         unsigned int prevstatus;
 251         unsigned int status;
 252         unsigned int changed;
 253
 254         spin_lock_irqsave(&priv->lock, flags);
 255         prevstatus = priv->line_status;
 256         spin_unlock_irqrestore(&priv->lock, flags);
 257
 258         while (1) {
 259                 interruptible_sleep_on(&priv->delta_msr_wait);
 260                 /* see if a signal did it */
 261                 if (signal_pending(current))
 262                         return -ERESTARTSYS;
 263
 264                 spin_lock_irqsave(&priv->lock, flags);
 265                 status = priv->line_status;
 266                 spin_unlock_irqrestore(&priv->lock, flags);
 267
 268                 changed = prevstatus ^ status;
 269
 270                 if (((arg & TIOCM_RNG) && (changed & UART_RING)) ||
 271                     ((arg & TIOCM_DSR) && (changed & UART_DSR)) ||
 272                     ((arg & TIOCM_CD)  && (changed & UART_DCD)) ||
 273                     ((arg & TIOCM_CTS) && (changed & UART_CTS))) {
 274                         return 0;
 275                 }
 276                 prevstatus = status;
 277         }
 278         /* NOTREACHED */
 279         return 0;
 280 }
 281
 282 static int f81232_ioctl(struct tty_struct *tty,
 283                         unsigned int cmd, unsigned long arg)
 284 {
 285         struct serial_struct ser;
 286         struct usb_serial_port *port = tty->driver_data;
 287
 288         dev_dbg(&port->dev, "%s (%d) cmd = 0x%04x\n", __func__,
 289                 port->number, cmd);
 290
 291         switch (cmd) {
 292         case TIOCGSERIAL:
 293                 memset(&ser, 0, sizeof ser);
 294                 ser.type = PORT_16654;
 295                 ser.line = port->serial->minor;
 296                 ser.port = port->number;
 297                 ser.baud_base = 460800;
 298
 299                 if (copy_to_user((void __user *)arg, &ser, sizeof ser))
 300                         return -EFAULT;
 301
 302                 return 0;
 303
 304         case TIOCMIWAIT:
 305                 dev_dbg(&port->dev, "%s (%d) TIOCMIWAIT\n", __func__,
 306                         port->number);
 307                 return wait_modem_info(port, arg);
 308         default:
 309                 dev_dbg(&port->dev, "%s not supported = 0x%04x\n",
 310                         __func__, cmd);
 311                 break;
 312         }
 313         return -ENOIOCTLCMD;
 314 }
 315
 316 static int f81232_port_probe(struct usb_serial_port *port)
 317 {
 318         struct f81232_private *priv;
 319
 320         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 321         if (!priv)
 322                 return -ENOMEM;
 323
 324         spin_lock_init(&priv->lock);
 325         init_waitqueue_head(&priv->delta_msr_wait);
 326
 327         usb_set_serial_port_data(port, priv);
 328
 329         return 0;
 330 }
 331
 332 static int f81232_port_remove(struct usb_serial_port *port)
 333 {
 334         struct f81232_private *priv;
 335
 336         priv = usb_get_serial_port_data(port);
 337         kfree(priv);
 338
 339         return 0;
 340 }
 341
 342 static struct usb_serial_driver f81232_device = {
 343         .driver = {
 344                 .owner =        THIS_MODULE,
 345                 .name =         "f81232",
 346         },
 347         .id_table =             id_table,
 348         .num_ports =            1,
 349         .bulk_in_size =         256,
 350         .bulk_out_size =        256,
 351         .open =                 f81232_open,
 352         .close =                f81232_close,
 353         .dtr_rts =              f81232_dtr_rts,
 354         .carrier_raised =       f81232_carrier_raised,
 355         .ioctl =                f81232_ioctl,
 356         .break_ctl =            f81232_break_ctl,
 357         .set_termios =          f81232_set_termios,
 358         .tiocmget =             f81232_tiocmget,
 359         .tiocmset =             f81232_tiocmset,
 360         .process_read_urb =     f81232_process_read_urb,
 361         .read_int_callback =    f81232_read_int_callback,
 362         .port_probe =           f81232_port_probe,
 363         .port_remove =          f81232_port_remove,
 364 };
 365
 366 static struct usb_serial_driver * const serial_drivers[] = {
 367         &f81232_device,
 368         NULL,
 369 };
 370
 371 module_usb_serial_driver(serial_drivers, id_table);
 372
 373 MODULE_DESCRIPTION("Fintek F81232 USB to serial adaptor driver");
 374 MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org");
 375 MODULE_LICENSE("GPL v2");