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         u8 line_control;
  51         u8 line_status;
  52 };
  53
  54 static void f81232_update_line_status(struct usb_serial_port *port,
  55                                       unsigned char *data,
  56                                       unsigned int actual_length)
  57 {
  58 }
  59
  60 static void f81232_read_int_callback(struct urb *urb)
  61 {
  62         struct usb_serial_port *port =  urb->context;
  63         unsigned char *data = urb->transfer_buffer;
  64         unsigned int actual_length = urb->actual_length;
  65         int status = urb->status;
  66         int retval;
  67
  68         switch (status) {
  69         case 0:
  70                 /* success */
  71                 break;
  72         case -ECONNRESET:
  73         case -ENOENT:
  74         case -ESHUTDOWN:
  75                 /* this urb is terminated, clean up */
  76                 dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
  77                         __func__, status);
  78                 return;
  79         default:
  80                 dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
  81                         __func__, status);
  82                 goto exit;
  83         }
  84
  85         usb_serial_debug_data(&port->dev, __func__,
  86                               urb->actual_length, urb->transfer_buffer);
  87
  88         f81232_update_line_status(port, data, actual_length);
  89
  90 exit:
  91         retval = usb_submit_urb(urb, GFP_ATOMIC);
  92         if (retval)
  93                 dev_err(&urb->dev->dev,
  94                         "%s - usb_submit_urb failed with result %d\n",
  95                         __func__, retval);
  96 }
  97
  98 static void f81232_process_read_urb(struct urb *urb)
  99 {
 100         struct usb_serial_port *port = urb->context;
 101         struct f81232_private *priv = usb_get_serial_port_data(port);
 102         unsigned char *data = urb->transfer_buffer;
 103         char tty_flag = TTY_NORMAL;
 104         unsigned long flags;
 105         u8 line_status;
 106         int i;
 107
 108         /* update line status */
 109         spin_lock_irqsave(&priv->lock, flags);
 110         line_status = priv->line_status;
 111         priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
 112         spin_unlock_irqrestore(&priv->lock, flags);
 113         wake_up_interruptible(&port->port.delta_msr_wait);
 114
 115         if (!urb->actual_length)
 116                 return;
 117
 118         /* break takes precedence over parity, */
 119         /* which takes precedence over framing errors */
 120         if (line_status & UART_BREAK_ERROR)
 121                 tty_flag = TTY_BREAK;
 122         else if (line_status & UART_PARITY_ERROR)
 123                 tty_flag = TTY_PARITY;
 124         else if (line_status & UART_FRAME_ERROR)
 125                 tty_flag = TTY_FRAME;
 126         dev_dbg(&port->dev, "%s - tty_flag = %d\n", __func__, tty_flag);
 127
 128         /* overrun is special, not associated with a char */
 129         if (line_status & UART_OVERRUN_ERROR)
 130                 tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
 131
 132         if (port->port.console && port->sysrq) {
 133                 for (i = 0; i < urb->actual_length; ++i)
 134                         if (!usb_serial_handle_sysrq_char(port, data[i]))
 135                                 tty_insert_flip_char(&port->port, data[i],
 136                                                 tty_flag);
 137         } else {
 138                 tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
 139                                                         urb->actual_length);
 140         }
 141
 142         tty_flip_buffer_push(&port->port);
 143 }
 144
 145 static int set_control_lines(struct usb_device *dev, u8 value)
 146 {
 147         /* FIXME - Stubbed out for now */
 148         return 0;
 149 }
 150
 151 static void f81232_break_ctl(struct tty_struct *tty, int break_state)
 152 {
 153         /* FIXME - Stubbed out for now */
 154
 155         /*
 156          * break_state = -1 to turn on break, and 0 to turn off break
 157          * see drivers/char/tty_io.c to see it used.
 158          * last_set_data_urb_value NEVER has the break bit set in it.
 159          */
 160 }
 161
 162 static void f81232_set_termios(struct tty_struct *tty,
 163                 struct usb_serial_port *port, struct ktermios *old_termios)
 164 {
 165         /* FIXME - Stubbed out for now */
 166
 167         /* Don't change anything if nothing has changed */
 168         if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
 169                 return;
 170
 171         /* Do the real work here... */
 172         if (old_termios)
 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         int result;
 192
 193         /* Setup termios */
 194         if (tty)
 195                 f81232_set_termios(tty, port, NULL);
 196
 197         result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
 198         if (result) {
 199                 dev_err(&port->dev, "%s - failed submitting interrupt urb,"
 200                         " error %d\n", __func__, result);
 201                 return result;
 202         }
 203
 204         result = usb_serial_generic_open(tty, port);
 205         if (result) {
 206                 usb_kill_urb(port->interrupt_in_urb);
 207                 return result;
 208         }
 209
 210         return 0;
 211 }
 212
 213 static void f81232_close(struct usb_serial_port *port)
 214 {
 215         usb_serial_generic_close(port);
 216         usb_kill_urb(port->interrupt_in_urb);
 217 }
 218
 219 static void f81232_dtr_rts(struct usb_serial_port *port, int on)
 220 {
 221         struct f81232_private *priv = usb_get_serial_port_data(port);
 222         unsigned long flags;
 223         u8 control;
 224
 225         spin_lock_irqsave(&priv->lock, flags);
 226         /* Change DTR and RTS */
 227         if (on)
 228                 priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
 229         else
 230                 priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
 231         control = priv->line_control;
 232         spin_unlock_irqrestore(&priv->lock, flags);
 233         set_control_lines(port->serial->dev, control);
 234 }
 235
 236 static int f81232_carrier_raised(struct usb_serial_port *port)
 237 {
 238         struct f81232_private *priv = usb_get_serial_port_data(port);
 239         if (priv->line_status & UART_DCD)
 240                 return 1;
 241         return 0;
 242 }
 243
 244 static int f81232_tiocmiwait(struct tty_struct *tty, unsigned long arg)
 245 {
 246         struct usb_serial_port *port = tty->driver_data;
 247         struct f81232_private *priv = usb_get_serial_port_data(port);
 248         unsigned long flags;
 249         unsigned int prevstatus;
 250         unsigned int status;
 251         unsigned int changed;
 252
 253         spin_lock_irqsave(&priv->lock, flags);
 254         prevstatus = priv->line_status;
 255         spin_unlock_irqrestore(&priv->lock, flags);
 256
 257         while (1) {
 258                 interruptible_sleep_on(&port->port.delta_msr_wait);
 259                 /* see if a signal did it */
 260                 if (signal_pending(current))
 261                         return -ERESTARTSYS;
 262
 263                 if (port->serial->disconnected)
 264                         return -EIO;
 265
 266                 spin_lock_irqsave(&priv->lock, flags);
 267                 status = priv->line_status;
 268                 spin_unlock_irqrestore(&priv->lock, flags);
 269
 270                 changed = prevstatus ^ status;
 271
 272                 if (((arg & TIOCM_RNG) && (changed & UART_RING)) ||
 273                     ((arg & TIOCM_DSR) && (changed & UART_DSR)) ||
 274                     ((arg & TIOCM_CD)  && (changed & UART_DCD)) ||
 275                     ((arg & TIOCM_CTS) && (changed & UART_CTS))) {
 276                         return 0;
 277                 }
 278                 prevstatus = status;
 279         }
 280         /* NOTREACHED */
 281         return 0;
 282 }
 283
 284 static int f81232_ioctl(struct tty_struct *tty,
 285                         unsigned int cmd, unsigned long arg)
 286 {
 287         struct serial_struct ser;
 288         struct usb_serial_port *port = tty->driver_data;
 289
 290         dev_dbg(&port->dev, "%s cmd = 0x%04x\n", __func__, cmd);
 291
 292         switch (cmd) {
 293         case TIOCGSERIAL:
 294                 memset(&ser, 0, sizeof ser);
 295                 ser.type = PORT_16654;
 296                 ser.line = port->minor;
 297                 ser.port = port->port_number;
 298                 ser.baud_base = 460800;
 299
 300                 if (copy_to_user((void __user *)arg, &ser, sizeof ser))
 301                         return -EFAULT;
 302
 303                 return 0;
 304         default:
 305                 dev_dbg(&port->dev, "%s not supported = 0x%04x\n",
 306                         __func__, cmd);
 307                 break;
 308         }
 309         return -ENOIOCTLCMD;
 310 }
 311
 312 static int f81232_port_probe(struct usb_serial_port *port)
 313 {
 314         struct f81232_private *priv;
 315
 316         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 317         if (!priv)
 318                 return -ENOMEM;
 319
 320         spin_lock_init(&priv->lock);
 321
 322         usb_set_serial_port_data(port, priv);
 323
 324         port->port.drain_delay = 256;
 325
 326         return 0;
 327 }
 328
 329 static int f81232_port_remove(struct usb_serial_port *port)
 330 {
 331         struct f81232_private *priv;
 332
 333         priv = usb_get_serial_port_data(port);
 334         kfree(priv);
 335
 336         return 0;
 337 }
 338
 339 static struct usb_serial_driver f81232_device = {
 340         .driver = {
 341                 .owner =        THIS_MODULE,
 342                 .name =         "f81232",
 343         },
 344         .id_table =             id_table,
 345         .num_ports =            1,
 346         .bulk_in_size =         256,
 347         .bulk_out_size =        256,
 348         .open =                 f81232_open,
 349         .close =                f81232_close,
 350         .dtr_rts =              f81232_dtr_rts,
 351         .carrier_raised =       f81232_carrier_raised,
 352         .ioctl =                f81232_ioctl,
 353         .break_ctl =            f81232_break_ctl,
 354         .set_termios =          f81232_set_termios,
 355         .tiocmget =             f81232_tiocmget,
 356         .tiocmset =             f81232_tiocmset,
 357         .tiocmiwait =           f81232_tiocmiwait,
 358         .process_read_urb =     f81232_process_read_urb,
 359         .read_int_callback =    f81232_read_int_callback,
 360         .port_probe =           f81232_port_probe,
 361         .port_remove =          f81232_port_remove,
 362 };
 363
 364 static struct usb_serial_driver * const serial_drivers[] = {
 365         &f81232_device,
 366         NULL,
 367 };
 368
 369 module_usb_serial_driver(serial_drivers, id_table);
 370
 371 MODULE_DESCRIPTION("Fintek F81232 USB to serial adaptor driver");
 372 MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org");
 373 MODULE_LICENSE("GPL v2");