drivers/staging/gdm724x/gdm_tty.c

   1 /*
   2  * Copyright (c) 2012 GCT Semiconductor, Inc. All rights reserved.
   3  *
   4  * This software is licensed under the terms of the GNU General Public
   5  * License version 2, as published by the Free Software Foundation, and
   6  * may be copied, distributed, and modified under those terms.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  15
  16 #include <linux/kernel.h>
  17 #include <linux/errno.h>
  18 #include <linux/tty.h>
  19 #include <linux/tty_driver.h>
  20 #include <linux/tty_flip.h>
  21 #include <linux/module.h>
  22 #include <linux/slab.h>
  23 #include <linux/usb/cdc.h>
  24 #include <linux/serial.h>
  25 #include "gdm_tty.h"
  26
  27 #define GDM_TTY_MAJOR 0
  28 #define GDM_TTY_MINOR 32
  29
  30 #define ACM_CTRL_DTR 0x01
  31 #define ACM_CTRL_RTS 0x02
  32 #define ACM_CTRL_DSR 0x02
  33 #define ACM_CTRL_RI  0x08
  34 #define ACM_CTRL_DCD 0x01
  35
  36 #define WRITE_SIZE 2048
  37
  38 #define MUX_TX_MAX_SIZE 2048
  39
  40 #define gdm_tty_send(n, d, l, i, c, b) (\
  41         n->tty_dev->send_func(n->tty_dev->priv_dev, d, l, i, c, b))
  42 #define gdm_tty_recv(n, c) (\
  43         n->tty_dev->recv_func(n->tty_dev->priv_dev, c))
  44 #define gdm_tty_send_control(n, r, v, d, l) (\
  45         n->tty_dev->send_control(n->tty_dev->priv_dev, r, v, d, l))
  46
  47 #define GDM_TTY_READY(gdm) (gdm && gdm->tty_dev && gdm->port.count)
  48
  49 static struct tty_driver *gdm_driver[TTY_MAX_COUNT];
  50 static struct gdm *gdm_table[TTY_MAX_COUNT][GDM_TTY_MINOR];
  51 static DEFINE_MUTEX(gdm_table_lock);
  52
  53 static char *DRIVER_STRING[TTY_MAX_COUNT] = {"GCTATC", "GCTDM"};
  54 static char *DEVICE_STRING[TTY_MAX_COUNT] = {"GCT-ATC", "GCT-DM"};
  55
  56 static void gdm_port_destruct(struct tty_port *port)
  57 {
  58         struct gdm *gdm = container_of(port, struct gdm, port);
  59
  60         mutex_lock(&gdm_table_lock);
  61         gdm_table[gdm->index][gdm->minor] = NULL;
  62         mutex_unlock(&gdm_table_lock);
  63
  64         kfree(gdm);
  65 }
  66
  67 static struct tty_port_operations gdm_port_ops = {
  68         .destruct = gdm_port_destruct,
  69 };
  70
  71 static int gdm_tty_install(struct tty_driver *driver, struct tty_struct *tty)
  72 {
  73         struct gdm *gdm = NULL;
  74         int ret;
  75         int i;
  76         int j;
  77
  78         j = GDM_TTY_MINOR;
  79         for (i = 0; i < TTY_MAX_COUNT; i++) {
  80                 if (!strcmp(tty->driver->driver_name, DRIVER_STRING[i])) {
  81                         j = tty->index;
  82                         break;
  83                 }
  84         }
  85
  86         if (j == GDM_TTY_MINOR)
  87                 return -ENODEV;
  88
  89         mutex_lock(&gdm_table_lock);
  90         gdm = gdm_table[i][j];
  91         if (gdm == NULL) {
  92                 mutex_unlock(&gdm_table_lock);
  93                 return -ENODEV;
  94         }
  95
  96         tty_port_get(&gdm->port);
  97
  98         ret = tty_standard_install(driver, tty);
  99         if (ret) {
 100                 tty_port_put(&gdm->port);
 101                 mutex_unlock(&gdm_table_lock);
 102                 return ret;
 103         }
 104
 105         tty->driver_data = gdm;
 106         mutex_unlock(&gdm_table_lock);
 107
 108         return 0;
 109 }
 110
 111 static int gdm_tty_open(struct tty_struct *tty, struct file *filp)
 112 {
 113         struct gdm *gdm = tty->driver_data;
 114         return tty_port_open(&gdm->port, tty, filp);
 115 }
 116
 117 static void gdm_tty_cleanup(struct tty_struct *tty)
 118 {
 119         struct gdm *gdm = tty->driver_data;
 120         tty_port_put(&gdm->port);
 121 }
 122
 123 static void gdm_tty_hangup(struct tty_struct *tty)
 124 {
 125         struct gdm *gdm = tty->driver_data;
 126         tty_port_hangup(&gdm->port);
 127 }
 128
 129 static void gdm_tty_close(struct tty_struct *tty, struct file *filp)
 130 {
 131         struct gdm *gdm = tty->driver_data;
 132         tty_port_close(&gdm->port, tty, filp);
 133 }
 134
 135 static int gdm_tty_recv_complete(void *data,
 136                                  int len,
 137                                  int index,
 138                                  struct tty_dev *tty_dev,
 139                                  int complete)
 140 {
 141         struct gdm *gdm = tty_dev->gdm[index];
 142         if (!GDM_TTY_READY(gdm)) {
 143                 if (complete == RECV_PACKET_PROCESS_COMPLETE)
 144                         gdm_tty_recv(gdm, gdm_tty_recv_complete);
 145                 return TO_HOST_PORT_CLOSE;
 146         }
 147
 148         if (data && len) {
 149                 if (tty_buffer_request_room(&gdm->port, len) == len) {
 150                         tty_insert_flip_string(&gdm->port, data, len);
 151                         tty_flip_buffer_push(&gdm->port);
 152                 } else {
 153                         return TO_HOST_BUFFER_REQUEST_FAIL;
 154                 }
 155         }
 156
 157         if (complete == RECV_PACKET_PROCESS_COMPLETE)
 158                 gdm_tty_recv(gdm, gdm_tty_recv_complete);
 159
 160         return 0;
 161 }
 162
 163 static void gdm_tty_send_complete(void *arg)
 164 {
 165         struct gdm *gdm = (struct gdm *)arg;
 166
 167         if (!GDM_TTY_READY(gdm))
 168                 return;
 169
 170         tty_port_tty_wakeup(&gdm->port);
 171 }
 172
 173 static int gdm_tty_write(struct tty_struct *tty, const unsigned char *buf,
 174                          int len)
 175 {
 176         struct gdm *gdm = tty->driver_data;
 177         int remain = len;
 178         int sent_len = 0;
 179         int sending_len = 0;
 180
 181         if (!GDM_TTY_READY(gdm))
 182                 return -ENODEV;
 183
 184         if (!len)
 185                 return 0;
 186
 187         while (1) {
 188                 sending_len = remain > MUX_TX_MAX_SIZE ? MUX_TX_MAX_SIZE :
 189                                                          remain;
 190                 gdm_tty_send(gdm,
 191                              (void *)(buf+sent_len),
 192                              sending_len,
 193                              gdm->index,
 194                              gdm_tty_send_complete,
 195                              gdm
 196                             );
 197                 sent_len += sending_len;
 198                 remain -= sending_len;
 199                 if (remain <= 0)
 200                         break;
 201         }
 202
 203         return len;
 204 }
 205
 206 static int gdm_tty_write_room(struct tty_struct *tty)
 207 {
 208         struct gdm *gdm = tty->driver_data;
 209
 210         if (!GDM_TTY_READY(gdm))
 211                 return -ENODEV;
 212
 213         return WRITE_SIZE;
 214 }
 215
 216 int register_lte_tty_device(struct tty_dev *tty_dev, struct device *device)
 217 {
 218         struct gdm *gdm;
 219         int i;
 220         int j;
 221
 222         for (i = 0; i < TTY_MAX_COUNT; i++) {
 223
 224                 gdm = kmalloc(sizeof(struct gdm), GFP_KERNEL);
 225                 if (!gdm)
 226                         return -ENOMEM;
 227
 228                 mutex_lock(&gdm_table_lock);
 229                 for (j = 0; j < GDM_TTY_MINOR; j++) {
 230                         if (!gdm_table[i][j])
 231                                 break;
 232                 }
 233
 234                 if (j == GDM_TTY_MINOR) {
 235                         kfree(gdm);
 236                         mutex_unlock(&gdm_table_lock);
 237                         return -EINVAL;
 238                 }
 239
 240                 gdm_table[i][j] = gdm;
 241                 mutex_unlock(&gdm_table_lock);
 242
 243                 tty_dev->gdm[i] = gdm;
 244                 tty_port_init(&gdm->port);
 245
 246                 gdm->port.ops = &gdm_port_ops;
 247                 gdm->index = i;
 248                 gdm->minor = j;
 249                 gdm->tty_dev = tty_dev;
 250
 251                 tty_port_register_device(&gdm->port, gdm_driver[i],
 252                                          gdm->minor, device);
 253         }
 254
 255         for (i = 0; i < MAX_ISSUE_NUM; i++)
 256                 gdm_tty_recv(gdm, gdm_tty_recv_complete);
 257
 258         return 0;
 259 }
 260
 261 void unregister_lte_tty_device(struct tty_dev *tty_dev)
 262 {
 263         struct gdm *gdm;
 264         struct tty_struct *tty;
 265         int i;
 266
 267         for (i = 0; i < TTY_MAX_COUNT; i++) {
 268                 gdm = tty_dev->gdm[i];
 269                 if (!gdm)
 270                         continue;
 271
 272                 mutex_lock(&gdm_table_lock);
 273                 gdm_table[gdm->index][gdm->minor] = NULL;
 274                 mutex_unlock(&gdm_table_lock);
 275
 276                 tty = tty_port_tty_get(&gdm->port);
 277                 if (tty) {
 278                         tty_vhangup(tty);
 279                         tty_kref_put(tty);
 280                 }
 281
 282                 tty_unregister_device(gdm_driver[i], gdm->minor);
 283                 tty_port_put(&gdm->port);
 284         }
 285 }
 286
 287 static const struct tty_operations gdm_tty_ops = {
 288         .install =      gdm_tty_install,
 289         .open =         gdm_tty_open,
 290         .close =        gdm_tty_close,
 291         .cleanup =      gdm_tty_cleanup,
 292         .hangup =       gdm_tty_hangup,
 293         .write =        gdm_tty_write,
 294         .write_room =   gdm_tty_write_room,
 295 };
 296
 297 int register_lte_tty_driver(void)
 298 {
 299         struct tty_driver *tty_driver;
 300         int i;
 301         int ret;
 302
 303         for (i = 0; i < TTY_MAX_COUNT; i++) {
 304                 tty_driver = alloc_tty_driver(GDM_TTY_MINOR);
 305                 if (!tty_driver)
 306                         return -ENOMEM;
 307
 308                 tty_driver->owner = THIS_MODULE;
 309                 tty_driver->driver_name = DRIVER_STRING[i];
 310                 tty_driver->name = DEVICE_STRING[i];
 311                 tty_driver->major = GDM_TTY_MAJOR;
 312                 tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
 313                 tty_driver->subtype = SERIAL_TYPE_NORMAL;
 314                 tty_driver->flags = TTY_DRIVER_REAL_RAW |
 315                                         TTY_DRIVER_DYNAMIC_DEV;
 316                 tty_driver->init_termios = tty_std_termios;
 317                 tty_driver->init_termios.c_cflag = B9600 | CS8 | HUPCL | CLOCAL;
 318                 tty_driver->init_termios.c_lflag = ISIG | ICANON | IEXTEN;
 319                 tty_set_operations(tty_driver, &gdm_tty_ops);
 320
 321                 ret = tty_register_driver(tty_driver);
 322                 if (ret) {
 323                         put_tty_driver(tty_driver);
 324                         return ret;
 325                 }
 326
 327                 gdm_driver[i] = tty_driver;
 328         }
 329
 330         return ret;
 331 }
 332
 333 void unregister_lte_tty_driver(void)
 334 {
 335         struct tty_driver *tty_driver;
 336         int i;
 337
 338         for (i = 0; i < TTY_MAX_COUNT; i++) {
 339                 tty_driver = gdm_driver[i];
 340                 if (tty_driver) {
 341                         tty_unregister_driver(tty_driver);
 342                         put_tty_driver(tty_driver);
 343                 }
 344         }
 345 }
 346