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/mutex.h>
  23 #include <linux/uaccess.h>
  24 #include <linux/usb.h>
  25 #include <linux/usb/serial.h>
  26 #include <linux/serial_reg.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         struct mutex lock;
  50         u8 line_control;
  51         u8 modem_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          * FIXME: Update port->icount, and call
  60          *
  61          *              wake_up_interruptible(&port->port.delta_msr_wait);
  62          *
  63          *        on MSR changes.
  64          */
  65 }
  66
  67 static void f81232_read_int_callback(struct urb *urb)
  68 {
  69         struct usb_serial_port *port =  urb->context;
  70         unsigned char *data = urb->transfer_buffer;
  71         unsigned int actual_length = urb->actual_length;
  72         int status = urb->status;
  73         int retval;
  74
  75         switch (status) {
  76         case 0:
  77                 /* success */
  78                 break;
  79         case -ECONNRESET:
  80         case -ENOENT:
  81         case -ESHUTDOWN:
  82                 /* this urb is terminated, clean up */
  83                 dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
  84                         __func__, status);
  85                 return;
  86         default:
  87                 dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
  88                         __func__, status);
  89                 goto exit;
  90         }
  91
  92         usb_serial_debug_data(&port->dev, __func__,
  93                               urb->actual_length, urb->transfer_buffer);
  94
  95         f81232_update_line_status(port, data, actual_length);
  96
  97 exit:
  98         retval = usb_submit_urb(urb, GFP_ATOMIC);
  99         if (retval)
 100                 dev_err(&urb->dev->dev,
 101                         "%s - usb_submit_urb failed with result %d\n",
 102                         __func__, retval);
 103 }
 104
 105 static void f81232_process_read_urb(struct urb *urb)
 106 {
 107         struct usb_serial_port *port = urb->context;
 108         unsigned char *data = urb->transfer_buffer;
 109         char tty_flag;
 110         unsigned int i;
 111         u8 lsr;
 112
 113         /*
 114          * When opening the port we get a 1-byte packet with the current LSR,
 115          * which we discard.
 116          */
 117         if ((urb->actual_length < 2) || (urb->actual_length % 2))
 118                 return;
 119
 120         /* bulk-in data: [LSR(1Byte)+DATA(1Byte)][LSR(1Byte)+DATA(1Byte)]... */
 121
 122         for (i = 0; i < urb->actual_length; i += 2) {
 123                 tty_flag = TTY_NORMAL;
 124                 lsr = data[i];
 125
 126                 if (lsr & UART_LSR_BRK_ERROR_BITS) {
 127                         if (lsr & UART_LSR_BI) {
 128                                 tty_flag = TTY_BREAK;
 129                                 port->icount.brk++;
 130                                 usb_serial_handle_break(port);
 131                         } else if (lsr & UART_LSR_PE) {
 132                                 tty_flag = TTY_PARITY;
 133                                 port->icount.parity++;
 134                         } else if (lsr & UART_LSR_FE) {
 135                                 tty_flag = TTY_FRAME;
 136                                 port->icount.frame++;
 137                         }
 138
 139                         if (lsr & UART_LSR_OE) {
 140                                 port->icount.overrun++;
 141                                 tty_insert_flip_char(&port->port, 0,
 142                                                 TTY_OVERRUN);
 143                         }
 144                 }
 145
 146                 if (port->port.console && port->sysrq) {
 147                         if (usb_serial_handle_sysrq_char(port, data[i + 1]))
 148                                 continue;
 149                 }
 150
 151                 tty_insert_flip_char(&port->port, data[i + 1], tty_flag);
 152         }
 153
 154         tty_flip_buffer_push(&port->port);
 155 }
 156
 157 static int set_control_lines(struct usb_device *dev, u8 value)
 158 {
 159         /* FIXME - Stubbed out for now */
 160         return 0;
 161 }
 162
 163 static void f81232_break_ctl(struct tty_struct *tty, int break_state)
 164 {
 165         /* FIXME - Stubbed out for now */
 166
 167         /*
 168          * break_state = -1 to turn on break, and 0 to turn off break
 169          * see drivers/char/tty_io.c to see it used.
 170          * last_set_data_urb_value NEVER has the break bit set in it.
 171          */
 172 }
 173
 174 static void f81232_set_termios(struct tty_struct *tty,
 175                 struct usb_serial_port *port, struct ktermios *old_termios)
 176 {
 177         /* FIXME - Stubbed out for now */
 178
 179         /* Don't change anything if nothing has changed */
 180         if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
 181                 return;
 182
 183         /* Do the real work here... */
 184         if (old_termios)
 185                 tty_termios_copy_hw(&tty->termios, old_termios);
 186 }
 187
 188 static int f81232_tiocmget(struct tty_struct *tty)
 189 {
 190         /* FIXME - Stubbed out for now */
 191         return 0;
 192 }
 193
 194 static int f81232_tiocmset(struct tty_struct *tty,
 195                         unsigned int set, unsigned int clear)
 196 {
 197         /* FIXME - Stubbed out for now */
 198         return 0;
 199 }
 200
 201 static int f81232_open(struct tty_struct *tty, struct usb_serial_port *port)
 202 {
 203         int result;
 204
 205         /* Setup termios */
 206         if (tty)
 207                 f81232_set_termios(tty, port, NULL);
 208
 209         result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
 210         if (result) {
 211                 dev_err(&port->dev, "%s - failed submitting interrupt urb,"
 212                         " error %d\n", __func__, result);
 213                 return result;
 214         }
 215
 216         result = usb_serial_generic_open(tty, port);
 217         if (result) {
 218                 usb_kill_urb(port->interrupt_in_urb);
 219                 return result;
 220         }
 221
 222         return 0;
 223 }
 224
 225 static void f81232_close(struct usb_serial_port *port)
 226 {
 227         usb_serial_generic_close(port);
 228         usb_kill_urb(port->interrupt_in_urb);
 229 }
 230
 231 static void f81232_dtr_rts(struct usb_serial_port *port, int on)
 232 {
 233         struct f81232_private *priv = usb_get_serial_port_data(port);
 234         u8 control;
 235
 236         mutex_lock(&priv->lock);
 237         /* Change DTR and RTS */
 238         if (on)
 239                 priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
 240         else
 241                 priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
 242         control = priv->line_control;
 243         mutex_unlock(&priv->lock);
 244         set_control_lines(port->serial->dev, control);
 245 }
 246
 247 static int f81232_carrier_raised(struct usb_serial_port *port)
 248 {
 249         struct f81232_private *priv = usb_get_serial_port_data(port);
 250         if (priv->modem_status & UART_DCD)
 251                 return 1;
 252         return 0;
 253 }
 254
 255 static int f81232_ioctl(struct tty_struct *tty,
 256                         unsigned int cmd, unsigned long arg)
 257 {
 258         struct serial_struct ser;
 259         struct usb_serial_port *port = tty->driver_data;
 260
 261         switch (cmd) {
 262         case TIOCGSERIAL:
 263                 memset(&ser, 0, sizeof ser);
 264                 ser.type = PORT_16654;
 265                 ser.line = port->minor;
 266                 ser.port = port->port_number;
 267                 ser.baud_base = 460800;
 268
 269                 if (copy_to_user((void __user *)arg, &ser, sizeof ser))
 270                         return -EFAULT;
 271
 272                 return 0;
 273         default:
 274                 break;
 275         }
 276         return -ENOIOCTLCMD;
 277 }
 278
 279 static int f81232_port_probe(struct usb_serial_port *port)
 280 {
 281         struct f81232_private *priv;
 282
 283         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 284         if (!priv)
 285                 return -ENOMEM;
 286
 287         mutex_init(&priv->lock);
 288
 289         usb_set_serial_port_data(port, priv);
 290
 291         port->port.drain_delay = 256;
 292
 293         return 0;
 294 }
 295
 296 static int f81232_port_remove(struct usb_serial_port *port)
 297 {
 298         struct f81232_private *priv;
 299
 300         priv = usb_get_serial_port_data(port);
 301         kfree(priv);
 302
 303         return 0;
 304 }
 305
 306 static struct usb_serial_driver f81232_device = {
 307         .driver = {
 308                 .owner =        THIS_MODULE,
 309                 .name =         "f81232",
 310         },
 311         .id_table =             id_table,
 312         .num_ports =            1,
 313         .bulk_in_size =         256,
 314         .bulk_out_size =        256,
 315         .open =                 f81232_open,
 316         .close =                f81232_close,
 317         .dtr_rts =              f81232_dtr_rts,
 318         .carrier_raised =       f81232_carrier_raised,
 319         .ioctl =                f81232_ioctl,
 320         .break_ctl =            f81232_break_ctl,
 321         .set_termios =          f81232_set_termios,
 322         .tiocmget =             f81232_tiocmget,
 323         .tiocmset =             f81232_tiocmset,
 324         .tiocmiwait =           usb_serial_generic_tiocmiwait,
 325         .process_read_urb =     f81232_process_read_urb,
 326         .read_int_callback =    f81232_read_int_callback,
 327         .port_probe =           f81232_port_probe,
 328         .port_remove =          f81232_port_remove,
 329 };
 330
 331 static struct usb_serial_driver * const serial_drivers[] = {
 332         &f81232_device,
 333         NULL,
 334 };
 335
 336 module_usb_serial_driver(serial_drivers, id_table);
 337
 338 MODULE_DESCRIPTION("Fintek F81232 USB to serial adaptor driver");
 339 MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org");
 340 MODULE_LICENSE("GPL v2");