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