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 ACM_CTRL_DTR 0x01
21 #define ACM_CTRL_RTS 0x02
22 #define ACM_CTRL_DSR 0x02
23 #define ACM_CTRL_RI 0x08
24 #define ACM_CTRL_DCD 0x01
25
26 #define WRITE_SIZE 2048
27
28 #define MUX_TX_MAX_SIZE 2048
29
30 #define GDM_TTY_READY(gdm) (gdm && gdm->tty_dev && gdm->port.count)
31
32 static struct tty_driver *gdm_driver[TTY_MAX_COUNT];
33 static struct gdm *gdm_table[TTY_MAX_COUNT][GDM_TTY_MINOR];
34 static DEFINE_MUTEX(gdm_table_lock);
35
36 static const char *DRIVER_STRING[TTY_MAX_COUNT] = {"GCTATC", "GCTDM"};
37 static char *DEVICE_STRING[TTY_MAX_COUNT] = {"GCT-ATC", "GCT-DM"};
38
gdm_port_destruct(struct tty_port * port)39 static void gdm_port_destruct(struct tty_port *port)
40 {
41 struct gdm *gdm = container_of(port, struct gdm, port);
42
43 mutex_lock(&gdm_table_lock);
44 gdm_table[gdm->index][gdm->minor] = NULL;
45 mutex_unlock(&gdm_table_lock);
46
47 kfree(gdm);
48 }
49
50 static const struct tty_port_operations gdm_port_ops = {
51 .destruct = gdm_port_destruct,
52 };
53
gdm_tty_install(struct tty_driver * driver,struct tty_struct * tty)54 static int gdm_tty_install(struct tty_driver *driver, struct tty_struct *tty)
55 {
56 struct gdm *gdm = NULL;
57 int ret;
58
59 ret = match_string(DRIVER_STRING, TTY_MAX_COUNT,
60 tty->driver->driver_name);
61 if (ret < 0)
62 return -ENODEV;
63
64 mutex_lock(&gdm_table_lock);
65 gdm = gdm_table[ret][tty->index];
66 if (!gdm) {
67 mutex_unlock(&gdm_table_lock);
68 return -ENODEV;
69 }
70
71 tty_port_get(&gdm->port);
72
73 ret = tty_standard_install(driver, tty);
74 if (ret) {
75 tty_port_put(&gdm->port);
76 mutex_unlock(&gdm_table_lock);
77 return ret;
78 }
79
80 tty->driver_data = gdm;
81 mutex_unlock(&gdm_table_lock);
82
83 return 0;
84 }
85
gdm_tty_open(struct tty_struct * tty,struct file * filp)86 static int gdm_tty_open(struct tty_struct *tty, struct file *filp)
87 {
88 struct gdm *gdm = tty->driver_data;
89
90 return tty_port_open(&gdm->port, tty, filp);
91 }
92
gdm_tty_cleanup(struct tty_struct * tty)93 static void gdm_tty_cleanup(struct tty_struct *tty)
94 {
95 struct gdm *gdm = tty->driver_data;
96
97 tty_port_put(&gdm->port);
98 }
99
gdm_tty_hangup(struct tty_struct * tty)100 static void gdm_tty_hangup(struct tty_struct *tty)
101 {
102 struct gdm *gdm = tty->driver_data;
103
104 tty_port_hangup(&gdm->port);
105 }
106
gdm_tty_close(struct tty_struct * tty,struct file * filp)107 static void gdm_tty_close(struct tty_struct *tty, struct file *filp)
108 {
109 struct gdm *gdm = tty->driver_data;
110
111 tty_port_close(&gdm->port, tty, filp);
112 }
113
gdm_tty_recv_complete(void * data,int len,int index,struct tty_dev * tty_dev,int complete)114 static int gdm_tty_recv_complete(void *data,
115 int len,
116 int index,
117 struct tty_dev *tty_dev,
118 int complete)
119 {
120 struct gdm *gdm = tty_dev->gdm[index];
121
122 if (!GDM_TTY_READY(gdm)) {
123 if (complete == RECV_PACKET_PROCESS_COMPLETE)
124 gdm->tty_dev->recv_func(gdm->tty_dev->priv_dev,
125 gdm_tty_recv_complete);
126 return TO_HOST_PORT_CLOSE;
127 }
128
129 if (data && len) {
130 if (tty_buffer_request_room(&gdm->port, len) == len) {
131 tty_insert_flip_string(&gdm->port, data, len);
132 tty_flip_buffer_push(&gdm->port);
133 } else {
134 return TO_HOST_BUFFER_REQUEST_FAIL;
135 }
136 }
137
138 if (complete == RECV_PACKET_PROCESS_COMPLETE)
139 gdm->tty_dev->recv_func(gdm->tty_dev->priv_dev,
140 gdm_tty_recv_complete);
141
142 return 0;
143 }
144
gdm_tty_send_complete(void * arg)145 static void gdm_tty_send_complete(void *arg)
146 {
147 struct gdm *gdm = arg;
148
149 if (!GDM_TTY_READY(gdm))
150 return;
151
152 tty_port_tty_wakeup(&gdm->port);
153 }
154
gdm_tty_write(struct tty_struct * tty,const unsigned char * buf,int len)155 static int gdm_tty_write(struct tty_struct *tty, const unsigned char *buf,
156 int len)
157 {
158 struct gdm *gdm = tty->driver_data;
159 int remain = len;
160 int sent_len = 0;
161 int sending_len = 0;
162
163 if (!GDM_TTY_READY(gdm))
164 return -ENODEV;
165
166 if (!len)
167 return 0;
168
169 while (1) {
170 sending_len = min(MUX_TX_MAX_SIZE, remain);
171 gdm->tty_dev->send_func(gdm->tty_dev->priv_dev,
172 (void *)(buf + sent_len),
173 sending_len,
174 gdm->index,
175 gdm_tty_send_complete,
176 gdm);
177 sent_len += sending_len;
178 remain -= sending_len;
179 if (remain <= 0)
180 break;
181 }
182
183 return len;
184 }
185
gdm_tty_write_room(struct tty_struct * tty)186 static unsigned int gdm_tty_write_room(struct tty_struct *tty)
187 {
188 struct gdm *gdm = tty->driver_data;
189
190 if (!GDM_TTY_READY(gdm))
191 return 0;
192
193 return WRITE_SIZE;
194 }
195
register_lte_tty_device(struct tty_dev * tty_dev,struct device * device)196 int register_lte_tty_device(struct tty_dev *tty_dev, struct device *device)
197 {
198 struct gdm *gdm;
199 int i;
200 int j;
201
202 for (i = 0; i < TTY_MAX_COUNT; i++) {
203 gdm = kmalloc(sizeof(*gdm), GFP_KERNEL);
204 if (!gdm)
205 return -ENOMEM;
206
207 mutex_lock(&gdm_table_lock);
208 for (j = 0; j < GDM_TTY_MINOR; j++) {
209 if (!gdm_table[i][j])
210 break;
211 }
212
213 if (j == GDM_TTY_MINOR) {
214 kfree(gdm);
215 mutex_unlock(&gdm_table_lock);
216 return -EINVAL;
217 }
218
219 gdm_table[i][j] = gdm;
220 mutex_unlock(&gdm_table_lock);
221
222 tty_dev->gdm[i] = gdm;
223 tty_port_init(&gdm->port);
224
225 gdm->port.ops = &gdm_port_ops;
226 gdm->index = i;
227 gdm->minor = j;
228 gdm->tty_dev = tty_dev;
229
230 tty_port_register_device(&gdm->port, gdm_driver[i],
231 gdm->minor, device);
232 }
233
234 for (i = 0; i < MAX_ISSUE_NUM; i++)
235 gdm->tty_dev->recv_func(gdm->tty_dev->priv_dev,
236 gdm_tty_recv_complete);
237
238 return 0;
239 }
240
unregister_lte_tty_device(struct tty_dev * tty_dev)241 void unregister_lte_tty_device(struct tty_dev *tty_dev)
242 {
243 struct gdm *gdm;
244 struct tty_struct *tty;
245 int i;
246
247 for (i = 0; i < TTY_MAX_COUNT; i++) {
248 gdm = tty_dev->gdm[i];
249 if (!gdm)
250 continue;
251
252 mutex_lock(&gdm_table_lock);
253 gdm_table[gdm->index][gdm->minor] = NULL;
254 mutex_unlock(&gdm_table_lock);
255
256 tty = tty_port_tty_get(&gdm->port);
257 if (tty) {
258 tty_vhangup(tty);
259 tty_kref_put(tty);
260 }
261
262 tty_unregister_device(gdm_driver[i], gdm->minor);
263 tty_port_put(&gdm->port);
264 }
265 }
266
267 static const struct tty_operations gdm_tty_ops = {
268 .install = gdm_tty_install,
269 .open = gdm_tty_open,
270 .close = gdm_tty_close,
271 .cleanup = gdm_tty_cleanup,
272 .hangup = gdm_tty_hangup,
273 .write = gdm_tty_write,
274 .write_room = gdm_tty_write_room,
275 };
276
register_lte_tty_driver(void)277 int register_lte_tty_driver(void)
278 {
279 struct tty_driver *tty_driver;
280 int i;
281 int ret;
282
283 for (i = 0; i < TTY_MAX_COUNT; i++) {
284 tty_driver = tty_alloc_driver(GDM_TTY_MINOR,
285 TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV);
286 if (IS_ERR(tty_driver))
287 return PTR_ERR(tty_driver);
288
289 tty_driver->owner = THIS_MODULE;
290 tty_driver->driver_name = DRIVER_STRING[i];
291 tty_driver->name = DEVICE_STRING[i];
292 tty_driver->major = GDM_TTY_MAJOR;
293 tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
294 tty_driver->subtype = SERIAL_TYPE_NORMAL;
295 tty_driver->init_termios = tty_std_termios;
296 tty_driver->init_termios.c_cflag = B9600 | CS8 | HUPCL | CLOCAL;
297 tty_driver->init_termios.c_lflag = ISIG | ICANON | IEXTEN;
298 tty_set_operations(tty_driver, &gdm_tty_ops);
299
300 ret = tty_register_driver(tty_driver);
301 if (ret) {
302 tty_driver_kref_put(tty_driver);
303 return ret;
304 }
305
306 gdm_driver[i] = tty_driver;
307 }
308
309 return ret;
310 }
311
unregister_lte_tty_driver(void)312 void unregister_lte_tty_driver(void)
313 {
314 struct tty_driver *tty_driver;
315 int i;
316
317 for (i = 0; i < TTY_MAX_COUNT; i++) {
318 tty_driver = gdm_driver[i];
319 if (tty_driver) {
320 tty_unregister_driver(tty_driver);
321 tty_driver_kref_put(tty_driver);
322 }
323 }
324 }
325
326