1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2012 GCT Semiconductor, Inc. All rights reserved. */ 3 4 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 5 6 #include <linux/kernel.h> 7 #include <linux/errno.h> 8 #include <linux/tty.h> 9 #include <linux/tty_driver.h> 10 #include <linux/tty_flip.h> 11 #include <linux/module.h> 12 #include <linux/slab.h> 13 #include <linux/usb/cdc.h> 14 #include <linux/serial.h> 15 #include "gdm_tty.h" 16 17 #define GDM_TTY_MAJOR 0 18 #define GDM_TTY_MINOR 32 19 20 #define WRITE_SIZE 2048 21 22 #define MUX_TX_MAX_SIZE 2048 23 24 static inline bool gdm_tty_ready(struct gdm *gdm) 25 { 26 return gdm && gdm->tty_dev && gdm->port.count; 27 } 28 29 static struct tty_driver *gdm_driver[TTY_MAX_COUNT]; 30 static struct gdm *gdm_table[TTY_MAX_COUNT][GDM_TTY_MINOR]; 31 static DEFINE_MUTEX(gdm_table_lock); 32 33 static const char *DRIVER_STRING[TTY_MAX_COUNT] = {"GCTATC", "GCTDM"}; 34 static char *DEVICE_STRING[TTY_MAX_COUNT] = {"GCT-ATC", "GCT-DM"}; 35 36 static void gdm_port_destruct(struct tty_port *port) 37 { 38 struct gdm *gdm = container_of(port, struct gdm, port); 39 40 mutex_lock(&gdm_table_lock); 41 gdm_table[gdm->index][gdm->minor] = NULL; 42 mutex_unlock(&gdm_table_lock); 43 44 kfree(gdm); 45 } 46 47 static const struct tty_port_operations gdm_port_ops = { 48 .destruct = gdm_port_destruct, 49 }; 50 51 static int gdm_tty_install(struct tty_driver *driver, struct tty_struct *tty) 52 { 53 struct gdm *gdm = NULL; 54 int ret; 55 56 ret = match_string(DRIVER_STRING, TTY_MAX_COUNT, 57 tty->driver->driver_name); 58 if (ret < 0) 59 return -ENODEV; 60 61 mutex_lock(&gdm_table_lock); 62 gdm = gdm_table[ret][tty->index]; 63 if (!gdm) { 64 mutex_unlock(&gdm_table_lock); 65 return -ENODEV; 66 } 67 68 tty_port_get(&gdm->port); 69 70 ret = tty_standard_install(driver, tty); 71 if (ret) { 72 tty_port_put(&gdm->port); 73 mutex_unlock(&gdm_table_lock); 74 return ret; 75 } 76 77 tty->driver_data = gdm; 78 mutex_unlock(&gdm_table_lock); 79 80 return 0; 81 } 82 83 static int gdm_tty_open(struct tty_struct *tty, struct file *filp) 84 { 85 struct gdm *gdm = tty->driver_data; 86 87 return tty_port_open(&gdm->port, tty, filp); 88 } 89 90 static void gdm_tty_cleanup(struct tty_struct *tty) 91 { 92 struct gdm *gdm = tty->driver_data; 93 94 tty_port_put(&gdm->port); 95 } 96 97 static void gdm_tty_hangup(struct tty_struct *tty) 98 { 99 struct gdm *gdm = tty->driver_data; 100 101 tty_port_hangup(&gdm->port); 102 } 103 104 static void gdm_tty_close(struct tty_struct *tty, struct file *filp) 105 { 106 struct gdm *gdm = tty->driver_data; 107 108 tty_port_close(&gdm->port, tty, filp); 109 } 110 111 static int gdm_tty_recv_complete(void *data, 112 int len, 113 int index, 114 struct tty_dev *tty_dev, 115 int complete) 116 { 117 struct gdm *gdm = tty_dev->gdm[index]; 118 119 if (!gdm_tty_ready(gdm)) { 120 if (complete == RECV_PACKET_PROCESS_COMPLETE) 121 gdm->tty_dev->recv_func(gdm->tty_dev->priv_dev, 122 gdm_tty_recv_complete); 123 return TO_HOST_PORT_CLOSE; 124 } 125 126 if (data && len) { 127 if (tty_buffer_request_room(&gdm->port, len) == len) { 128 tty_insert_flip_string(&gdm->port, data, len); 129 tty_flip_buffer_push(&gdm->port); 130 } else { 131 return TO_HOST_BUFFER_REQUEST_FAIL; 132 } 133 } 134 135 if (complete == RECV_PACKET_PROCESS_COMPLETE) 136 gdm->tty_dev->recv_func(gdm->tty_dev->priv_dev, 137 gdm_tty_recv_complete); 138 139 return 0; 140 } 141 142 static void gdm_tty_send_complete(void *arg) 143 { 144 struct gdm *gdm = arg; 145 146 if (!gdm_tty_ready(gdm)) 147 return; 148 149 tty_port_tty_wakeup(&gdm->port); 150 } 151 152 static int gdm_tty_write(struct tty_struct *tty, const unsigned char *buf, 153 int len) 154 { 155 struct gdm *gdm = tty->driver_data; 156 int remain = len; 157 int sent_len = 0; 158 int sending_len = 0; 159 160 if (!gdm_tty_ready(gdm)) 161 return -ENODEV; 162 163 if (!len) 164 return 0; 165 166 while (1) { 167 sending_len = min(MUX_TX_MAX_SIZE, remain); 168 gdm->tty_dev->send_func(gdm->tty_dev->priv_dev, 169 (void *)(buf + sent_len), 170 sending_len, 171 gdm->index, 172 gdm_tty_send_complete, 173 gdm); 174 sent_len += sending_len; 175 remain -= sending_len; 176 if (remain <= 0) 177 break; 178 } 179 180 return len; 181 } 182 183 static unsigned int gdm_tty_write_room(struct tty_struct *tty) 184 { 185 struct gdm *gdm = tty->driver_data; 186 187 if (!gdm_tty_ready(gdm)) 188 return 0; 189 190 return WRITE_SIZE; 191 } 192 193 int register_lte_tty_device(struct tty_dev *tty_dev, struct device *device) 194 { 195 struct gdm *gdm; 196 int i; 197 int j; 198 199 for (i = 0; i < TTY_MAX_COUNT; i++) { 200 gdm = kmalloc(sizeof(*gdm), GFP_KERNEL); 201 if (!gdm) 202 return -ENOMEM; 203 204 mutex_lock(&gdm_table_lock); 205 for (j = 0; j < GDM_TTY_MINOR; j++) { 206 if (!gdm_table[i][j]) 207 break; 208 } 209 210 if (j == GDM_TTY_MINOR) { 211 kfree(gdm); 212 mutex_unlock(&gdm_table_lock); 213 return -EINVAL; 214 } 215 216 gdm_table[i][j] = gdm; 217 mutex_unlock(&gdm_table_lock); 218 219 tty_dev->gdm[i] = gdm; 220 tty_port_init(&gdm->port); 221 222 gdm->port.ops = &gdm_port_ops; 223 gdm->index = i; 224 gdm->minor = j; 225 gdm->tty_dev = tty_dev; 226 227 tty_port_register_device(&gdm->port, gdm_driver[i], 228 gdm->minor, device); 229 } 230 231 for (i = 0; i < MAX_ISSUE_NUM; i++) 232 gdm->tty_dev->recv_func(gdm->tty_dev->priv_dev, 233 gdm_tty_recv_complete); 234 235 return 0; 236 } 237 238 void unregister_lte_tty_device(struct tty_dev *tty_dev) 239 { 240 struct gdm *gdm; 241 struct tty_struct *tty; 242 int i; 243 244 for (i = 0; i < TTY_MAX_COUNT; i++) { 245 gdm = tty_dev->gdm[i]; 246 if (!gdm) 247 continue; 248 249 mutex_lock(&gdm_table_lock); 250 gdm_table[gdm->index][gdm->minor] = NULL; 251 mutex_unlock(&gdm_table_lock); 252 253 tty = tty_port_tty_get(&gdm->port); 254 if (tty) { 255 tty_vhangup(tty); 256 tty_kref_put(tty); 257 } 258 259 tty_unregister_device(gdm_driver[i], gdm->minor); 260 tty_port_put(&gdm->port); 261 } 262 } 263 264 static const struct tty_operations gdm_tty_ops = { 265 .install = gdm_tty_install, 266 .open = gdm_tty_open, 267 .close = gdm_tty_close, 268 .cleanup = gdm_tty_cleanup, 269 .hangup = gdm_tty_hangup, 270 .write = gdm_tty_write, 271 .write_room = gdm_tty_write_room, 272 }; 273 274 int register_lte_tty_driver(void) 275 { 276 struct tty_driver *tty_driver; 277 int i; 278 int ret; 279 280 for (i = 0; i < TTY_MAX_COUNT; i++) { 281 tty_driver = tty_alloc_driver(GDM_TTY_MINOR, 282 TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV); 283 if (IS_ERR(tty_driver)) 284 return PTR_ERR(tty_driver); 285 286 tty_driver->owner = THIS_MODULE; 287 tty_driver->driver_name = DRIVER_STRING[i]; 288 tty_driver->name = DEVICE_STRING[i]; 289 tty_driver->major = GDM_TTY_MAJOR; 290 tty_driver->type = TTY_DRIVER_TYPE_SERIAL; 291 tty_driver->subtype = SERIAL_TYPE_NORMAL; 292 tty_driver->init_termios = tty_std_termios; 293 tty_driver->init_termios.c_cflag = B9600 | CS8 | HUPCL | CLOCAL; 294 tty_driver->init_termios.c_lflag = ISIG | ICANON | IEXTEN; 295 tty_set_operations(tty_driver, &gdm_tty_ops); 296 297 ret = tty_register_driver(tty_driver); 298 if (ret) { 299 tty_driver_kref_put(tty_driver); 300 return ret; 301 } 302 303 gdm_driver[i] = tty_driver; 304 } 305 306 return ret; 307 } 308 309 void unregister_lte_tty_driver(void) 310 { 311 struct tty_driver *tty_driver; 312 int i; 313 314 for (i = 0; i < TTY_MAX_COUNT; i++) { 315 tty_driver = gdm_driver[i]; 316 if (tty_driver) { 317 tty_unregister_driver(tty_driver); 318 tty_driver_kref_put(tty_driver); 319 } 320 } 321 } 322 323