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 bool debug;
  29
  30 static const struct usb_device_id id_table[] = {
  31         { USB_DEVICE(0x1934, 0x0706) },
  32         { }                                     /* Terminating entry */
  33 };
  34 MODULE_DEVICE_TABLE(usb, id_table);
  35
  36 #define CONTROL_DTR                     0x01
  37 #define CONTROL_RTS                     0x02
  38
  39 #define UART_STATE                      0x08
  40 #define UART_STATE_TRANSIENT_MASK       0x74
  41 #define UART_DCD                        0x01
  42 #define UART_DSR                        0x02
  43 #define UART_BREAK_ERROR                0x04
  44 #define UART_RING                       0x08
  45 #define UART_FRAME_ERROR                0x10
  46 #define UART_PARITY_ERROR               0x20
  47 #define UART_OVERRUN_ERROR              0x40
  48 #define UART_CTS                        0x80
  49
  50 struct f81232_private {
  51         spinlock_t lock;
  52         wait_queue_head_t delta_msr_wait;
  53         u8 line_control;
  54         u8 line_status;
  55 };
  56
  57 static void f81232_update_line_status(struct usb_serial_port *port,
  58                                       unsigned char *data,
  59                                       unsigned int actual_length)
  60 {
  61 }
  62
  63 static void f81232_read_int_callback(struct urb *urb)
  64 {
  65         struct usb_serial_port *port =  urb->context;
  66         unsigned char *data = urb->transfer_buffer;
  67         unsigned int actual_length = urb->actual_length;
  68         int status = urb->status;
  69         int retval;
  70
  71         switch (status) {
  72         case 0:
  73                 /* success */
  74                 break;
  75         case -ECONNRESET:
  76         case -ENOENT:
  77         case -ESHUTDOWN:
  78                 /* this urb is terminated, clean up */
  79                 dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
  80                         __func__, status);
  81                 return;
  82         default:
  83                 dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
  84                         __func__, status);
  85                 goto exit;
  86         }
  87
  88         usb_serial_debug_data(debug, &port->dev, __func__,
  89                               urb->actual_length, urb->transfer_buffer);
  90
  91         f81232_update_line_status(port, data, actual_length);
  92
  93 exit:
  94         retval = usb_submit_urb(urb, GFP_ATOMIC);
  95         if (retval)
  96                 dev_err(&urb->dev->dev,
  97                         "%s - usb_submit_urb failed with result %d\n",
  98                         __func__, retval);
  99 }
 100
 101 static void f81232_process_read_urb(struct urb *urb)
 102 {
 103         struct usb_serial_port *port = urb->context;
 104         struct f81232_private *priv = usb_get_serial_port_data(port);
 105         struct tty_struct *tty;
 106         unsigned char *data = urb->transfer_buffer;
 107         char tty_flag = TTY_NORMAL;
 108         unsigned long flags;
 109         u8 line_status;
 110         int i;
 111
 112         /* update line status */
 113         spin_lock_irqsave(&priv->lock, flags);
 114         line_status = priv->line_status;
 115         priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
 116         spin_unlock_irqrestore(&priv->lock, flags);
 117         wake_up_interruptible(&priv->delta_msr_wait);
 118
 119         if (!urb->actual_length)
 120                 return;
 121
 122         tty = tty_port_tty_get(&port->port);
 123         if (!tty)
 124                 return;
 125
 126         /* break takes precedence over parity, */
 127         /* which takes precedence over framing errors */
 128         if (line_status & UART_BREAK_ERROR)
 129                 tty_flag = TTY_BREAK;
 130         else if (line_status & UART_PARITY_ERROR)
 131                 tty_flag = TTY_PARITY;
 132         else if (line_status & UART_FRAME_ERROR)
 133                 tty_flag = TTY_FRAME;
 134         dev_dbg(&port->dev, "%s - tty_flag = %d\n", __func__, tty_flag);
 135
 136         /* overrun is special, not associated with a char */
 137         if (line_status & UART_OVERRUN_ERROR)
 138                 tty_insert_flip_char(tty, 0, TTY_OVERRUN);
 139
 140         if (port->port.console && port->sysrq) {
 141                 for (i = 0; i < urb->actual_length; ++i)
 142                         if (!usb_serial_handle_sysrq_char(port, data[i]))
 143                                 tty_insert_flip_char(tty, data[i], tty_flag);
 144         } else {
 145                 tty_insert_flip_string_fixed_flag(tty, data, tty_flag,
 146                                                         urb->actual_length);
 147         }
 148
 149         tty_flip_buffer_push(tty);
 150         tty_kref_put(tty);
 151 }
 152
 153 static int set_control_lines(struct usb_device *dev, u8 value)
 154 {
 155         /* FIXME - Stubbed out for now */
 156         return 0;
 157 }
 158
 159 static void f81232_break_ctl(struct tty_struct *tty, int break_state)
 160 {
 161         /* FIXME - Stubbed out for now */
 162
 163         /*
 164          * break_state = -1 to turn on break, and 0 to turn off break
 165          * see drivers/char/tty_io.c to see it used.
 166          * last_set_data_urb_value NEVER has the break bit set in it.
 167          */
 168 }
 169
 170 static void f81232_set_termios(struct tty_struct *tty,
 171                 struct usb_serial_port *port, struct ktermios *old_termios)
 172 {
 173         /* FIXME - Stubbed out for now */
 174
 175         /* Don't change anything if nothing has changed */
 176         if (!tty_termios_hw_change(tty->termios, old_termios))
 177                 return;
 178
 179         /* Do the real work here... */
 180 }
 181
 182 static int f81232_tiocmget(struct tty_struct *tty)
 183 {
 184         /* FIXME - Stubbed out for now */
 185         return 0;
 186 }
 187
 188 static int f81232_tiocmset(struct tty_struct *tty,
 189                         unsigned int set, unsigned int clear)
 190 {
 191         /* FIXME - Stubbed out for now */
 192         return 0;
 193 }
 194
 195 static int f81232_open(struct tty_struct *tty, struct usb_serial_port *port)
 196 {
 197         struct ktermios tmp_termios;
 198         int result;
 199
 200         /* Setup termios */
 201         if (tty)
 202                 f81232_set_termios(tty, port, &tmp_termios);
 203
 204         result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
 205         if (result) {
 206                 dev_err(&port->dev, "%s - failed submitting interrupt urb,"
 207                         " error %d\n", __func__, result);
 208                 return result;
 209         }
 210
 211         result = usb_serial_generic_open(tty, port);
 212         if (result) {
 213                 usb_kill_urb(port->interrupt_in_urb);
 214                 return result;
 215         }
 216
 217         port->port.drain_delay = 256;
 218         return 0;
 219 }
 220
 221 static void f81232_close(struct usb_serial_port *port)
 222 {
 223         usb_serial_generic_close(port);
 224         usb_kill_urb(port->interrupt_in_urb);
 225 }
 226
 227 static void f81232_dtr_rts(struct usb_serial_port *port, int on)
 228 {
 229         struct f81232_private *priv = usb_get_serial_port_data(port);
 230         unsigned long flags;
 231         u8 control;
 232
 233         spin_lock_irqsave(&priv->lock, flags);
 234         /* Change DTR and RTS */
 235         if (on)
 236                 priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
 237         else
 238                 priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
 239         control = priv->line_control;
 240         spin_unlock_irqrestore(&priv->lock, flags);
 241         set_control_lines(port->serial->dev, control);
 242 }
 243
 244 static int f81232_carrier_raised(struct usb_serial_port *port)
 245 {
 246         struct f81232_private *priv = usb_get_serial_port_data(port);
 247         if (priv->line_status & UART_DCD)
 248                 return 1;
 249         return 0;
 250 }
 251
 252 static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
 253 {
 254         struct f81232_private *priv = usb_get_serial_port_data(port);
 255         unsigned long flags;
 256         unsigned int prevstatus;
 257         unsigned int status;
 258         unsigned int changed;
 259
 260         spin_lock_irqsave(&priv->lock, flags);
 261         prevstatus = priv->line_status;
 262         spin_unlock_irqrestore(&priv->lock, flags);
 263
 264         while (1) {
 265                 interruptible_sleep_on(&priv->delta_msr_wait);
 266                 /* see if a signal did it */
 267                 if (signal_pending(current))
 268                         return -ERESTARTSYS;
 269
 270                 spin_lock_irqsave(&priv->lock, flags);
 271                 status = priv->line_status;
 272                 spin_unlock_irqrestore(&priv->lock, flags);
 273
 274                 changed = prevstatus ^ status;
 275
 276                 if (((arg & TIOCM_RNG) && (changed & UART_RING)) ||
 277                     ((arg & TIOCM_DSR) && (changed & UART_DSR)) ||
 278                     ((arg & TIOCM_CD)  && (changed & UART_DCD)) ||
 279                     ((arg & TIOCM_CTS) && (changed & UART_CTS))) {
 280                         return 0;
 281                 }
 282                 prevstatus = status;
 283         }
 284         /* NOTREACHED */
 285         return 0;
 286 }
 287
 288 static int f81232_ioctl(struct tty_struct *tty,
 289                         unsigned int cmd, unsigned long arg)
 290 {
 291         struct serial_struct ser;
 292         struct usb_serial_port *port = tty->driver_data;
 293
 294         dev_dbg(&port->dev, "%s (%d) cmd = 0x%04x\n", __func__,
 295                 port->number, cmd);
 296
 297         switch (cmd) {
 298         case TIOCGSERIAL:
 299                 memset(&ser, 0, sizeof ser);
 300                 ser.type = PORT_16654;
 301                 ser.line = port->serial->minor;
 302                 ser.port = port->number;
 303                 ser.baud_base = 460800;
 304
 305                 if (copy_to_user((void __user *)arg, &ser, sizeof ser))
 306                         return -EFAULT;
 307
 308                 return 0;
 309
 310         case TIOCMIWAIT:
 311                 dev_dbg(&port->dev, "%s (%d) TIOCMIWAIT\n", __func__,
 312                         port->number);
 313                 return wait_modem_info(port, arg);
 314         default:
 315                 dev_dbg(&port->dev, "%s not supported = 0x%04x\n",
 316                         __func__, cmd);
 317                 break;
 318         }
 319         return -ENOIOCTLCMD;
 320 }
 321
 322 static int f81232_port_probe(struct usb_serial_port *port)
 323 {
 324         struct f81232_private *priv;
 325
 326         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 327         if (!priv)
 328                 return -ENOMEM;
 329
 330         spin_lock_init(&priv->lock);
 331         init_waitqueue_head(&priv->delta_msr_wait);
 332
 333         usb_set_serial_port_data(port, priv);
 334
 335         return 0;
 336 }
 337
 338 static int f81232_port_remove(struct usb_serial_port *port)
 339 {
 340         struct f81232_private *priv;
 341
 342         priv = usb_get_serial_port_data(port);
 343         kfree(priv);
 344
 345         return 0;
 346 }
 347
 348 static struct usb_serial_driver f81232_device = {
 349         .driver = {
 350                 .owner =        THIS_MODULE,
 351                 .name =         "f81232",
 352         },
 353         .id_table =             id_table,
 354         .num_ports =            1,
 355         .bulk_in_size =         256,
 356         .bulk_out_size =        256,
 357         .open =                 f81232_open,
 358         .close =                f81232_close,
 359         .dtr_rts =              f81232_dtr_rts,
 360         .carrier_raised =       f81232_carrier_raised,
 361         .ioctl =                f81232_ioctl,
 362         .break_ctl =            f81232_break_ctl,
 363         .set_termios =          f81232_set_termios,
 364         .tiocmget =             f81232_tiocmget,
 365         .tiocmset =             f81232_tiocmset,
 366         .process_read_urb =     f81232_process_read_urb,
 367         .read_int_callback =    f81232_read_int_callback,
 368         .port_probe =           f81232_port_probe,
 369         .port_remove =          f81232_port_remove,
 370 };
 371
 372 static struct usb_serial_driver * const serial_drivers[] = {
 373         &f81232_device,
 374         NULL,
 375 };
 376
 377 module_usb_serial_driver(serial_drivers, id_table);
 378
 379 MODULE_DESCRIPTION("Fintek F81232 USB to serial adaptor driver");
 380 MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org");
 381 MODULE_LICENSE("GPL v2");
 382
 383 module_param(debug, bool, S_IRUGO | S_IWUSR);
 384 MODULE_PARM_DESC(debug, "Debug enabled or not");
 385