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 }
 179
 180 static int f81232_tiocmget(struct tty_struct *tty)
 181 {
 182         /* FIXME - Stubbed out for now */
 183         return 0;
 184 }
 185
 186 static int f81232_tiocmset(struct tty_struct *tty,
 187                         unsigned int set, unsigned int clear)
 188 {
 189         /* FIXME - Stubbed out for now */
 190         return 0;
 191 }
 192
 193 static int f81232_open(struct tty_struct *tty, struct usb_serial_port *port)
 194 {
 195         struct ktermios tmp_termios;
 196         int result;
 197
 198         /* Setup termios */
 199         if (tty)
 200                 f81232_set_termios(tty, port, &tmp_termios);
 201
 202         result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
 203         if (result) {
 204                 dev_err(&port->dev, "%s - failed submitting interrupt urb,"
 205                         " error %d\n", __func__, result);
 206                 return result;
 207         }
 208
 209         result = usb_serial_generic_open(tty, port);
 210         if (result) {
 211                 usb_kill_urb(port->interrupt_in_urb);
 212                 return result;
 213         }
 214
 215         port->port.drain_delay = 256;
 216         return 0;
 217 }
 218
 219 static void f81232_close(struct usb_serial_port *port)
 220 {
 221         usb_serial_generic_close(port);
 222         usb_kill_urb(port->interrupt_in_urb);
 223 }
 224
 225 static void f81232_dtr_rts(struct usb_serial_port *port, int on)
 226 {
 227         struct f81232_private *priv = usb_get_serial_port_data(port);
 228         unsigned long flags;
 229         u8 control;
 230
 231         spin_lock_irqsave(&priv->lock, flags);
 232         /* Change DTR and RTS */
 233         if (on)
 234                 priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
 235         else
 236                 priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
 237         control = priv->line_control;
 238         spin_unlock_irqrestore(&priv->lock, flags);
 239         set_control_lines(port->serial->dev, control);
 240 }
 241
 242 static int f81232_carrier_raised(struct usb_serial_port *port)
 243 {
 244         struct f81232_private *priv = usb_get_serial_port_data(port);
 245         if (priv->line_status & UART_DCD)
 246                 return 1;
 247         return 0;
 248 }
 249
 250 static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
 251 {
 252         struct f81232_private *priv = usb_get_serial_port_data(port);
 253         unsigned long flags;
 254         unsigned int prevstatus;
 255         unsigned int status;
 256         unsigned int changed;
 257
 258         spin_lock_irqsave(&priv->lock, flags);
 259         prevstatus = priv->line_status;
 260         spin_unlock_irqrestore(&priv->lock, flags);
 261
 262         while (1) {
 263                 interruptible_sleep_on(&priv->delta_msr_wait);
 264                 /* see if a signal did it */
 265                 if (signal_pending(current))
 266                         return -ERESTARTSYS;
 267
 268                 spin_lock_irqsave(&priv->lock, flags);
 269                 status = priv->line_status;
 270                 spin_unlock_irqrestore(&priv->lock, flags);
 271
 272                 changed = prevstatus ^ status;
 273
 274                 if (((arg & TIOCM_RNG) && (changed & UART_RING)) ||
 275                     ((arg & TIOCM_DSR) && (changed & UART_DSR)) ||
 276                     ((arg & TIOCM_CD)  && (changed & UART_DCD)) ||
 277                     ((arg & TIOCM_CTS) && (changed & UART_CTS))) {
 278                         return 0;
 279                 }
 280                 prevstatus = status;
 281         }
 282         /* NOTREACHED */
 283         return 0;
 284 }
 285
 286 static int f81232_ioctl(struct tty_struct *tty,
 287                         unsigned int cmd, unsigned long arg)
 288 {
 289         struct serial_struct ser;
 290         struct usb_serial_port *port = tty->driver_data;
 291
 292         dev_dbg(&port->dev, "%s (%d) cmd = 0x%04x\n", __func__,
 293                 port->number, cmd);
 294
 295         switch (cmd) {
 296         case TIOCGSERIAL:
 297                 memset(&ser, 0, sizeof ser);
 298                 ser.type = PORT_16654;
 299                 ser.line = port->serial->minor;
 300                 ser.port = port->number;
 301                 ser.baud_base = 460800;
 302
 303                 if (copy_to_user((void __user *)arg, &ser, sizeof ser))
 304                         return -EFAULT;
 305
 306                 return 0;
 307
 308         case TIOCMIWAIT:
 309                 dev_dbg(&port->dev, "%s (%d) TIOCMIWAIT\n", __func__,
 310                         port->number);
 311                 return wait_modem_info(port, arg);
 312         default:
 313                 dev_dbg(&port->dev, "%s not supported = 0x%04x\n",
 314                         __func__, cmd);
 315                 break;
 316         }
 317         return -ENOIOCTLCMD;
 318 }
 319
 320 static int f81232_startup(struct usb_serial *serial)
 321 {
 322         struct f81232_private *priv;
 323         int i;
 324
 325         for (i = 0; i < serial->num_ports; ++i) {
 326                 priv = kzalloc(sizeof(struct f81232_private), GFP_KERNEL);
 327                 if (!priv)
 328                         goto cleanup;
 329                 spin_lock_init(&priv->lock);
 330                 init_waitqueue_head(&priv->delta_msr_wait);
 331                 usb_set_serial_port_data(serial->port[i], priv);
 332         }
 333         return 0;
 334
 335 cleanup:
 336         for (--i; i >= 0; --i) {
 337                 priv = usb_get_serial_port_data(serial->port[i]);
 338                 kfree(priv);
 339                 usb_set_serial_port_data(serial->port[i], NULL);
 340         }
 341         return -ENOMEM;
 342 }
 343
 344 static void f81232_release(struct usb_serial *serial)
 345 {
 346         int i;
 347         struct f81232_private *priv;
 348
 349         for (i = 0; i < serial->num_ports; ++i) {
 350                 priv = usb_get_serial_port_data(serial->port[i]);
 351                 kfree(priv);
 352         }
 353 }
 354
 355 static struct usb_serial_driver f81232_device = {
 356         .driver = {
 357                 .owner =        THIS_MODULE,
 358                 .name =         "f81232",
 359         },
 360         .id_table =             id_table,
 361         .num_ports =            1,
 362         .bulk_in_size =         256,
 363         .bulk_out_size =        256,
 364         .open =                 f81232_open,
 365         .close =                f81232_close,
 366         .dtr_rts =              f81232_dtr_rts,
 367         .carrier_raised =       f81232_carrier_raised,
 368         .ioctl =                f81232_ioctl,
 369         .break_ctl =            f81232_break_ctl,
 370         .set_termios =          f81232_set_termios,
 371         .tiocmget =             f81232_tiocmget,
 372         .tiocmset =             f81232_tiocmset,
 373         .process_read_urb =     f81232_process_read_urb,
 374         .read_int_callback =    f81232_read_int_callback,
 375         .attach =               f81232_startup,
 376         .release =              f81232_release,
 377 };
 378
 379 static struct usb_serial_driver * const serial_drivers[] = {
 380         &f81232_device,
 381         NULL,
 382 };
 383
 384 module_usb_serial_driver(serial_drivers, id_table);
 385
 386 MODULE_DESCRIPTION("Fintek F81232 USB to serial adaptor driver");
 387 MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org");
 388 MODULE_LICENSE("GPL v2");