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/spinlock.h>
  23 #include <linux/uaccess.h>
  24 #include <linux/usb.h>
  25 #include <linux/usb/serial.h>
  26
  27 static const struct usb_device_id id_table[] = {
  28         { USB_DEVICE(0x1934, 0x0706) },
  29         { }                                     /* Terminating entry */
  30 };
  31 MODULE_DEVICE_TABLE(usb, id_table);
  32
  33 #define CONTROL_DTR                     0x01
  34 #define CONTROL_RTS                     0x02
  35
  36 #define UART_STATE                      0x08
  37 #define UART_STATE_TRANSIENT_MASK       0x74
  38 #define UART_DCD                        0x01
  39 #define UART_DSR                        0x02
  40 #define UART_BREAK_ERROR                0x04
  41 #define UART_RING                       0x08
  42 #define UART_FRAME_ERROR                0x10
  43 #define UART_PARITY_ERROR               0x20
  44 #define UART_OVERRUN_ERROR              0x40
  45 #define UART_CTS                        0x80
  46
  47 struct f81232_private {
  48         spinlock_t lock;
  49         u8 line_control;
  50         u8 line_status;
  51 };
  52
  53 static void f81232_update_line_status(struct usb_serial_port *port,
  54                                       unsigned char *data,
  55                                       unsigned int actual_length)
  56 {
  57         /*
  58          * FIXME: Update port->icount, and call
  59          *
  60          *              wake_up_interruptible(&port->port.delta_msr_wait);
  61          *
  62          *        on MSR changes.
  63          */
  64 }
  65
  66 static void f81232_read_int_callback(struct urb *urb)
  67 {
  68         struct usb_serial_port *port =  urb->context;
  69         unsigned char *data = urb->transfer_buffer;
  70         unsigned int actual_length = urb->actual_length;
  71         int status = urb->status;
  72         int retval;
  73
  74         switch (status) {
  75         case 0:
  76                 /* success */
  77                 break;
  78         case -ECONNRESET:
  79         case -ENOENT:
  80         case -ESHUTDOWN:
  81                 /* this urb is terminated, clean up */
  82                 dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
  83                         __func__, status);
  84                 return;
  85         default:
  86                 dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
  87                         __func__, status);
  88                 goto exit;
  89         }
  90
  91         usb_serial_debug_data(&port->dev, __func__,
  92                               urb->actual_length, urb->transfer_buffer);
  93
  94         f81232_update_line_status(port, data, actual_length);
  95
  96 exit:
  97         retval = usb_submit_urb(urb, GFP_ATOMIC);
  98         if (retval)
  99                 dev_err(&urb->dev->dev,
 100                         "%s - usb_submit_urb failed with result %d\n",
 101                         __func__, retval);
 102 }
 103
 104 static void f81232_process_read_urb(struct urb *urb)
 105 {
 106         struct usb_serial_port *port = urb->context;
 107         struct f81232_private *priv = usb_get_serial_port_data(port);
 108         unsigned char *data = urb->transfer_buffer;
 109         char tty_flag = TTY_NORMAL;
 110         unsigned long flags;
 111         u8 line_status;
 112         int i;
 113
 114         /* update line status */
 115         spin_lock_irqsave(&priv->lock, flags);
 116         line_status = priv->line_status;
 117         priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
 118         spin_unlock_irqrestore(&priv->lock, flags);
 119
 120         if (!urb->actual_length)
 121                 return;
 122
 123         /* break takes precedence over parity, */
 124         /* which takes precedence over framing errors */
 125         if (line_status & UART_BREAK_ERROR)
 126                 tty_flag = TTY_BREAK;
 127         else if (line_status & UART_PARITY_ERROR)
 128                 tty_flag = TTY_PARITY;
 129         else if (line_status & UART_FRAME_ERROR)
 130                 tty_flag = TTY_FRAME;
 131         dev_dbg(&port->dev, "%s - tty_flag = %d\n", __func__, tty_flag);
 132
 133         /* overrun is special, not associated with a char */
 134         if (line_status & UART_OVERRUN_ERROR)
 135                 tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
 136
 137         if (port->port.console && port->sysrq) {
 138                 for (i = 0; i < urb->actual_length; ++i)
 139                         if (!usb_serial_handle_sysrq_char(port, data[i]))
 140                                 tty_insert_flip_char(&port->port, data[i],
 141                                                 tty_flag);
 142         } else {
 143                 tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
 144                                                         urb->actual_length);
 145         }
 146
 147         tty_flip_buffer_push(&port->port);
 148 }
 149
 150 static int set_control_lines(struct usb_device *dev, u8 value)
 151 {
 152         /* FIXME - Stubbed out for now */
 153         return 0;
 154 }
 155
 156 static void f81232_break_ctl(struct tty_struct *tty, int break_state)
 157 {
 158         /* FIXME - Stubbed out for now */
 159
 160         /*
 161          * break_state = -1 to turn on break, and 0 to turn off break
 162          * see drivers/char/tty_io.c to see it used.
 163          * last_set_data_urb_value NEVER has the break bit set in it.
 164          */
 165 }
 166
 167 static void f81232_set_termios(struct tty_struct *tty,
 168                 struct usb_serial_port *port, struct ktermios *old_termios)
 169 {
 170         /* FIXME - Stubbed out for now */
 171
 172         /* Don't change anything if nothing has changed */
 173         if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
 174                 return;
 175
 176         /* Do the real work here... */
 177         if (old_termios)
 178                 tty_termios_copy_hw(&tty->termios, old_termios);
 179 }
 180
 181 static int f81232_tiocmget(struct tty_struct *tty)
 182 {
 183         /* FIXME - Stubbed out for now */
 184         return 0;
 185 }
 186
 187 static int f81232_tiocmset(struct tty_struct *tty,
 188                         unsigned int set, unsigned int clear)
 189 {
 190         /* FIXME - Stubbed out for now */
 191         return 0;
 192 }
 193
 194 static int f81232_open(struct tty_struct *tty, struct usb_serial_port *port)
 195 {
 196         int result;
 197
 198         /* Setup termios */
 199         if (tty)
 200                 f81232_set_termios(tty, port, NULL);
 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         return 0;
 216 }
 217
 218 static void f81232_close(struct usb_serial_port *port)
 219 {
 220         usb_serial_generic_close(port);
 221         usb_kill_urb(port->interrupt_in_urb);
 222 }
 223
 224 static void f81232_dtr_rts(struct usb_serial_port *port, int on)
 225 {
 226         struct f81232_private *priv = usb_get_serial_port_data(port);
 227         unsigned long flags;
 228         u8 control;
 229
 230         spin_lock_irqsave(&priv->lock, flags);
 231         /* Change DTR and RTS */
 232         if (on)
 233                 priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
 234         else
 235                 priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
 236         control = priv->line_control;
 237         spin_unlock_irqrestore(&priv->lock, flags);
 238         set_control_lines(port->serial->dev, control);
 239 }
 240
 241 static int f81232_carrier_raised(struct usb_serial_port *port)
 242 {
 243         struct f81232_private *priv = usb_get_serial_port_data(port);
 244         if (priv->line_status & UART_DCD)
 245                 return 1;
 246         return 0;
 247 }
 248
 249 static int f81232_ioctl(struct tty_struct *tty,
 250                         unsigned int cmd, unsigned long arg)
 251 {
 252         struct serial_struct ser;
 253         struct usb_serial_port *port = tty->driver_data;
 254
 255         switch (cmd) {
 256         case TIOCGSERIAL:
 257                 memset(&ser, 0, sizeof ser);
 258                 ser.type = PORT_16654;
 259                 ser.line = port->minor;
 260                 ser.port = port->port_number;
 261                 ser.baud_base = 460800;
 262
 263                 if (copy_to_user((void __user *)arg, &ser, sizeof ser))
 264                         return -EFAULT;
 265
 266                 return 0;
 267         default:
 268                 break;
 269         }
 270         return -ENOIOCTLCMD;
 271 }
 272
 273 static int f81232_port_probe(struct usb_serial_port *port)
 274 {
 275         struct f81232_private *priv;
 276
 277         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 278         if (!priv)
 279                 return -ENOMEM;
 280
 281         spin_lock_init(&priv->lock);
 282
 283         usb_set_serial_port_data(port, priv);
 284
 285         port->port.drain_delay = 256;
 286
 287         return 0;
 288 }
 289
 290 static int f81232_port_remove(struct usb_serial_port *port)
 291 {
 292         struct f81232_private *priv;
 293
 294         priv = usb_get_serial_port_data(port);
 295         kfree(priv);
 296
 297         return 0;
 298 }
 299
 300 static struct usb_serial_driver f81232_device = {
 301         .driver = {
 302                 .owner =        THIS_MODULE,
 303                 .name =         "f81232",
 304         },
 305         .id_table =             id_table,
 306         .num_ports =            1,
 307         .bulk_in_size =         256,
 308         .bulk_out_size =        256,
 309         .open =                 f81232_open,
 310         .close =                f81232_close,
 311         .dtr_rts =              f81232_dtr_rts,
 312         .carrier_raised =       f81232_carrier_raised,
 313         .ioctl =                f81232_ioctl,
 314         .break_ctl =            f81232_break_ctl,
 315         .set_termios =          f81232_set_termios,
 316         .tiocmget =             f81232_tiocmget,
 317         .tiocmset =             f81232_tiocmset,
 318         .tiocmiwait =           usb_serial_generic_tiocmiwait,
 319         .process_read_urb =     f81232_process_read_urb,
 320         .read_int_callback =    f81232_read_int_callback,
 321         .port_probe =           f81232_port_probe,
 322         .port_remove =          f81232_port_remove,
 323 };
 324
 325 static struct usb_serial_driver * const serial_drivers[] = {
 326         &f81232_device,
 327         NULL,
 328 };
 329
 330 module_usb_serial_driver(serial_drivers, id_table);
 331
 332 MODULE_DESCRIPTION("Fintek F81232 USB to serial adaptor driver");
 333 MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org");
 334 MODULE_LICENSE("GPL v2");