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 gdm_tty_ready(struct gdm * gdm)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 gdm_port_destruct(struct tty_port * port)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 gdm_tty_install(struct tty_driver * driver,struct tty_struct * tty)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 gdm_tty_open(struct tty_struct * tty,struct file * filp)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 gdm_tty_cleanup(struct tty_struct * tty)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 gdm_tty_hangup(struct tty_struct * tty)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 gdm_tty_close(struct tty_struct * tty,struct file * filp)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 gdm_tty_recv_complete(void * data,int len,int index,struct tty_dev * tty_dev,int complete)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 gdm_tty_send_complete(void * arg)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 gdm_tty_write(struct tty_struct * tty,const u8 * buf,size_t len)152 static ssize_t gdm_tty_write(struct tty_struct *tty, const u8 *buf, size_t len) 153 { 154 struct gdm *gdm = tty->driver_data; 155 size_t remain = len; 156 size_t sent_len = 0; 157 158 if (!gdm_tty_ready(gdm)) 159 return -ENODEV; 160 161 while (remain) { 162 size_t sending_len = min_t(size_t, MUX_TX_MAX_SIZE, remain); 163 164 gdm->tty_dev->send_func(gdm->tty_dev->priv_dev, 165 (void *)(buf + sent_len), 166 sending_len, 167 gdm->index, 168 gdm_tty_send_complete, 169 gdm); 170 sent_len += sending_len; 171 remain -= sending_len; 172 } 173 174 return len; 175 } 176 gdm_tty_write_room(struct tty_struct * tty)177 static unsigned int gdm_tty_write_room(struct tty_struct *tty) 178 { 179 struct gdm *gdm = tty->driver_data; 180 181 if (!gdm_tty_ready(gdm)) 182 return 0; 183 184 return WRITE_SIZE; 185 } 186 register_lte_tty_device(struct tty_dev * tty_dev,struct device * device)187 int register_lte_tty_device(struct tty_dev *tty_dev, struct device *device) 188 { 189 struct gdm *gdm; 190 int i; 191 int j; 192 193 for (i = 0; i < TTY_MAX_COUNT; i++) { 194 gdm = kmalloc(sizeof(*gdm), GFP_KERNEL); 195 if (!gdm) 196 return -ENOMEM; 197 198 mutex_lock(&gdm_table_lock); 199 for (j = 0; j < GDM_TTY_MINOR; j++) { 200 if (!gdm_table[i][j]) 201 break; 202 } 203 204 if (j == GDM_TTY_MINOR) { 205 kfree(gdm); 206 mutex_unlock(&gdm_table_lock); 207 return -EINVAL; 208 } 209 210 gdm_table[i][j] = gdm; 211 mutex_unlock(&gdm_table_lock); 212 213 tty_dev->gdm[i] = gdm; 214 tty_port_init(&gdm->port); 215 216 gdm->port.ops = &gdm_port_ops; 217 gdm->index = i; 218 gdm->minor = j; 219 gdm->tty_dev = tty_dev; 220 221 tty_port_register_device(&gdm->port, gdm_driver[i], 222 gdm->minor, device); 223 } 224 225 for (i = 0; i < MAX_ISSUE_NUM; i++) 226 gdm->tty_dev->recv_func(gdm->tty_dev->priv_dev, 227 gdm_tty_recv_complete); 228 229 return 0; 230 } 231 unregister_lte_tty_device(struct tty_dev * tty_dev)232 void unregister_lte_tty_device(struct tty_dev *tty_dev) 233 { 234 struct gdm *gdm; 235 struct tty_struct *tty; 236 int i; 237 238 for (i = 0; i < TTY_MAX_COUNT; i++) { 239 gdm = tty_dev->gdm[i]; 240 if (!gdm) 241 continue; 242 243 mutex_lock(&gdm_table_lock); 244 gdm_table[gdm->index][gdm->minor] = NULL; 245 mutex_unlock(&gdm_table_lock); 246 247 tty = tty_port_tty_get(&gdm->port); 248 if (tty) { 249 tty_vhangup(tty); 250 tty_kref_put(tty); 251 } 252 253 tty_unregister_device(gdm_driver[i], gdm->minor); 254 tty_port_put(&gdm->port); 255 } 256 } 257 258 static const struct tty_operations gdm_tty_ops = { 259 .install = gdm_tty_install, 260 .open = gdm_tty_open, 261 .close = gdm_tty_close, 262 .cleanup = gdm_tty_cleanup, 263 .hangup = gdm_tty_hangup, 264 .write = gdm_tty_write, 265 .write_room = gdm_tty_write_room, 266 }; 267 register_lte_tty_driver(void)268 int register_lte_tty_driver(void) 269 { 270 struct tty_driver *tty_driver; 271 int i; 272 int ret; 273 274 for (i = 0; i < TTY_MAX_COUNT; i++) { 275 tty_driver = tty_alloc_driver(GDM_TTY_MINOR, 276 TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV); 277 if (IS_ERR(tty_driver)) 278 return PTR_ERR(tty_driver); 279 280 tty_driver->owner = THIS_MODULE; 281 tty_driver->driver_name = DRIVER_STRING[i]; 282 tty_driver->name = DEVICE_STRING[i]; 283 tty_driver->major = GDM_TTY_MAJOR; 284 tty_driver->type = TTY_DRIVER_TYPE_SERIAL; 285 tty_driver->subtype = SERIAL_TYPE_NORMAL; 286 tty_driver->init_termios = tty_std_termios; 287 tty_driver->init_termios.c_cflag = B9600 | CS8 | HUPCL | CLOCAL; 288 tty_driver->init_termios.c_lflag = ISIG | ICANON | IEXTEN; 289 tty_set_operations(tty_driver, &gdm_tty_ops); 290 291 ret = tty_register_driver(tty_driver); 292 if (ret) { 293 tty_driver_kref_put(tty_driver); 294 return ret; 295 } 296 297 gdm_driver[i] = tty_driver; 298 } 299 300 return ret; 301 } 302 unregister_lte_tty_driver(void)303 void unregister_lte_tty_driver(void) 304 { 305 struct tty_driver *tty_driver; 306 int i; 307 308 for (i = 0; i < TTY_MAX_COUNT; i++) { 309 tty_driver = gdm_driver[i]; 310 if (tty_driver) { 311 tty_unregister_driver(tty_driver); 312 tty_driver_kref_put(tty_driver); 313 } 314 } 315 } 316 317