1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Copyright (C) 2016-2017 Linaro Ltd., Rob Herring <robh@kernel.org> |
4 | */ |
5 | #include <linux/kernel.h> |
6 | #include <linux/serdev.h> |
7 | #include <linux/tty.h> |
8 | #include <linux/tty_driver.h> |
9 | #include <linux/poll.h> |
10 | |
11 | #define SERPORT_ACTIVE 1 |
12 | |
13 | struct serport { |
14 | struct tty_port *port; |
15 | struct tty_struct *tty; |
16 | struct tty_driver *tty_drv; |
17 | int tty_idx; |
18 | unsigned long flags; |
19 | }; |
20 | |
21 | /* |
22 | * Callback functions from the tty port. |
23 | */ |
24 | |
25 | static size_t ttyport_receive_buf(struct tty_port *port, const u8 *cp, |
26 | const u8 *fp, size_t count) |
27 | { |
28 | struct serdev_controller *ctrl = port->client_data; |
29 | struct serport *serport = serdev_controller_get_drvdata(ctrl); |
30 | int ret; |
31 | |
32 | if (!test_bit(SERPORT_ACTIVE, &serport->flags)) |
33 | return 0; |
34 | |
35 | ret = serdev_controller_receive_buf(ctrl, data: cp, count); |
36 | |
37 | dev_WARN_ONCE(&ctrl->dev, ret < 0 || ret > count, |
38 | "receive_buf returns %d (count = %zu)\n" , |
39 | ret, count); |
40 | if (ret < 0) |
41 | return 0; |
42 | else if (ret > count) |
43 | return count; |
44 | |
45 | return ret; |
46 | } |
47 | |
48 | static void ttyport_write_wakeup(struct tty_port *port) |
49 | { |
50 | struct serdev_controller *ctrl = port->client_data; |
51 | struct serport *serport = serdev_controller_get_drvdata(ctrl); |
52 | struct tty_struct *tty; |
53 | |
54 | tty = tty_port_tty_get(port); |
55 | if (!tty) |
56 | return; |
57 | |
58 | if (test_and_clear_bit(TTY_DO_WRITE_WAKEUP, addr: &tty->flags) && |
59 | test_bit(SERPORT_ACTIVE, &serport->flags)) |
60 | serdev_controller_write_wakeup(ctrl); |
61 | |
62 | /* Wake up any tty_wait_until_sent() */ |
63 | wake_up_interruptible(&tty->write_wait); |
64 | |
65 | tty_kref_put(tty); |
66 | } |
67 | |
68 | static const struct tty_port_client_operations client_ops = { |
69 | .receive_buf = ttyport_receive_buf, |
70 | .write_wakeup = ttyport_write_wakeup, |
71 | }; |
72 | |
73 | /* |
74 | * Callback functions from the serdev core. |
75 | */ |
76 | |
77 | static int ttyport_write_buf(struct serdev_controller *ctrl, const unsigned char *data, size_t len) |
78 | { |
79 | struct serport *serport = serdev_controller_get_drvdata(ctrl); |
80 | struct tty_struct *tty = serport->tty; |
81 | |
82 | if (!test_bit(SERPORT_ACTIVE, &serport->flags)) |
83 | return 0; |
84 | |
85 | set_bit(TTY_DO_WRITE_WAKEUP, addr: &tty->flags); |
86 | return tty->ops->write(serport->tty, data, len); |
87 | } |
88 | |
89 | static void ttyport_write_flush(struct serdev_controller *ctrl) |
90 | { |
91 | struct serport *serport = serdev_controller_get_drvdata(ctrl); |
92 | struct tty_struct *tty = serport->tty; |
93 | |
94 | tty_driver_flush_buffer(tty); |
95 | } |
96 | |
97 | static int ttyport_write_room(struct serdev_controller *ctrl) |
98 | { |
99 | struct serport *serport = serdev_controller_get_drvdata(ctrl); |
100 | struct tty_struct *tty = serport->tty; |
101 | |
102 | return tty_write_room(tty); |
103 | } |
104 | |
105 | static int ttyport_open(struct serdev_controller *ctrl) |
106 | { |
107 | struct serport *serport = serdev_controller_get_drvdata(ctrl); |
108 | struct tty_struct *tty; |
109 | struct ktermios ktermios; |
110 | int ret; |
111 | |
112 | tty = tty_init_dev(driver: serport->tty_drv, idx: serport->tty_idx); |
113 | if (IS_ERR(ptr: tty)) |
114 | return PTR_ERR(ptr: tty); |
115 | serport->tty = tty; |
116 | |
117 | if (!tty->ops->open || !tty->ops->close) { |
118 | ret = -ENODEV; |
119 | goto err_unlock; |
120 | } |
121 | |
122 | ret = tty->ops->open(serport->tty, NULL); |
123 | if (ret) |
124 | goto err_close; |
125 | |
126 | tty_unlock(tty: serport->tty); |
127 | |
128 | /* Bring the UART into a known 8 bits no parity hw fc state */ |
129 | ktermios = tty->termios; |
130 | ktermios.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP | |
131 | INLCR | IGNCR | ICRNL | IXON); |
132 | ktermios.c_oflag &= ~OPOST; |
133 | ktermios.c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN); |
134 | ktermios.c_cflag &= ~(CSIZE | PARENB); |
135 | ktermios.c_cflag |= CS8; |
136 | ktermios.c_cflag |= CRTSCTS; |
137 | /* Hangups are not supported so make sure to ignore carrier detect. */ |
138 | ktermios.c_cflag |= CLOCAL; |
139 | tty_set_termios(tty, kt: &ktermios); |
140 | |
141 | set_bit(SERPORT_ACTIVE, addr: &serport->flags); |
142 | |
143 | return 0; |
144 | |
145 | err_close: |
146 | tty->ops->close(tty, NULL); |
147 | err_unlock: |
148 | tty_unlock(tty); |
149 | tty_release_struct(tty, idx: serport->tty_idx); |
150 | |
151 | return ret; |
152 | } |
153 | |
154 | static void ttyport_close(struct serdev_controller *ctrl) |
155 | { |
156 | struct serport *serport = serdev_controller_get_drvdata(ctrl); |
157 | struct tty_struct *tty = serport->tty; |
158 | |
159 | clear_bit(SERPORT_ACTIVE, addr: &serport->flags); |
160 | |
161 | tty_lock(tty); |
162 | if (tty->ops->close) |
163 | tty->ops->close(tty, NULL); |
164 | tty_unlock(tty); |
165 | |
166 | tty_release_struct(tty, idx: serport->tty_idx); |
167 | } |
168 | |
169 | static unsigned int ttyport_set_baudrate(struct serdev_controller *ctrl, unsigned int speed) |
170 | { |
171 | struct serport *serport = serdev_controller_get_drvdata(ctrl); |
172 | struct tty_struct *tty = serport->tty; |
173 | struct ktermios ktermios = tty->termios; |
174 | |
175 | ktermios.c_cflag &= ~CBAUD; |
176 | tty_termios_encode_baud_rate(termios: &ktermios, ibaud: speed, obaud: speed); |
177 | |
178 | /* tty_set_termios() return not checked as it is always 0 */ |
179 | tty_set_termios(tty, kt: &ktermios); |
180 | return ktermios.c_ospeed; |
181 | } |
182 | |
183 | static void ttyport_set_flow_control(struct serdev_controller *ctrl, bool enable) |
184 | { |
185 | struct serport *serport = serdev_controller_get_drvdata(ctrl); |
186 | struct tty_struct *tty = serport->tty; |
187 | struct ktermios ktermios = tty->termios; |
188 | |
189 | if (enable) |
190 | ktermios.c_cflag |= CRTSCTS; |
191 | else |
192 | ktermios.c_cflag &= ~CRTSCTS; |
193 | |
194 | tty_set_termios(tty, kt: &ktermios); |
195 | } |
196 | |
197 | static int ttyport_set_parity(struct serdev_controller *ctrl, |
198 | enum serdev_parity parity) |
199 | { |
200 | struct serport *serport = serdev_controller_get_drvdata(ctrl); |
201 | struct tty_struct *tty = serport->tty; |
202 | struct ktermios ktermios = tty->termios; |
203 | |
204 | ktermios.c_cflag &= ~(PARENB | PARODD | CMSPAR); |
205 | if (parity != SERDEV_PARITY_NONE) { |
206 | ktermios.c_cflag |= PARENB; |
207 | if (parity == SERDEV_PARITY_ODD) |
208 | ktermios.c_cflag |= PARODD; |
209 | } |
210 | |
211 | tty_set_termios(tty, kt: &ktermios); |
212 | |
213 | if ((tty->termios.c_cflag & (PARENB | PARODD | CMSPAR)) != |
214 | (ktermios.c_cflag & (PARENB | PARODD | CMSPAR))) |
215 | return -EINVAL; |
216 | |
217 | return 0; |
218 | } |
219 | |
220 | static void ttyport_wait_until_sent(struct serdev_controller *ctrl, long timeout) |
221 | { |
222 | struct serport *serport = serdev_controller_get_drvdata(ctrl); |
223 | struct tty_struct *tty = serport->tty; |
224 | |
225 | tty_wait_until_sent(tty, timeout); |
226 | } |
227 | |
228 | static int ttyport_get_tiocm(struct serdev_controller *ctrl) |
229 | { |
230 | struct serport *serport = serdev_controller_get_drvdata(ctrl); |
231 | struct tty_struct *tty = serport->tty; |
232 | |
233 | if (!tty->ops->tiocmget) |
234 | return -EOPNOTSUPP; |
235 | |
236 | return tty->ops->tiocmget(tty); |
237 | } |
238 | |
239 | static int ttyport_set_tiocm(struct serdev_controller *ctrl, unsigned int set, unsigned int clear) |
240 | { |
241 | struct serport *serport = serdev_controller_get_drvdata(ctrl); |
242 | struct tty_struct *tty = serport->tty; |
243 | |
244 | if (!tty->ops->tiocmset) |
245 | return -EOPNOTSUPP; |
246 | |
247 | return tty->ops->tiocmset(tty, set, clear); |
248 | } |
249 | |
250 | static int ttyport_break_ctl(struct serdev_controller *ctrl, unsigned int break_state) |
251 | { |
252 | struct serport *serport = serdev_controller_get_drvdata(ctrl); |
253 | struct tty_struct *tty = serport->tty; |
254 | |
255 | if (!tty->ops->break_ctl) |
256 | return -EOPNOTSUPP; |
257 | |
258 | return tty->ops->break_ctl(tty, break_state); |
259 | } |
260 | |
261 | static const struct serdev_controller_ops ctrl_ops = { |
262 | .write_buf = ttyport_write_buf, |
263 | .write_flush = ttyport_write_flush, |
264 | .write_room = ttyport_write_room, |
265 | .open = ttyport_open, |
266 | .close = ttyport_close, |
267 | .set_flow_control = ttyport_set_flow_control, |
268 | .set_parity = ttyport_set_parity, |
269 | .set_baudrate = ttyport_set_baudrate, |
270 | .wait_until_sent = ttyport_wait_until_sent, |
271 | .get_tiocm = ttyport_get_tiocm, |
272 | .set_tiocm = ttyport_set_tiocm, |
273 | .break_ctl = ttyport_break_ctl, |
274 | }; |
275 | |
276 | struct device *serdev_tty_port_register(struct tty_port *port, |
277 | struct device *parent, |
278 | struct tty_driver *drv, int idx) |
279 | { |
280 | struct serdev_controller *ctrl; |
281 | struct serport *serport; |
282 | int ret; |
283 | |
284 | if (!port || !drv || !parent) |
285 | return ERR_PTR(error: -ENODEV); |
286 | |
287 | ctrl = serdev_controller_alloc(parent, sizeof(struct serport)); |
288 | if (!ctrl) |
289 | return ERR_PTR(error: -ENOMEM); |
290 | serport = serdev_controller_get_drvdata(ctrl); |
291 | |
292 | serport->port = port; |
293 | serport->tty_idx = idx; |
294 | serport->tty_drv = drv; |
295 | |
296 | ctrl->ops = &ctrl_ops; |
297 | |
298 | port->client_ops = &client_ops; |
299 | port->client_data = ctrl; |
300 | |
301 | ret = serdev_controller_add(ctrl); |
302 | if (ret) |
303 | goto err_reset_data; |
304 | |
305 | dev_info(&ctrl->dev, "tty port %s%d registered\n" , drv->name, idx); |
306 | return &ctrl->dev; |
307 | |
308 | err_reset_data: |
309 | port->client_data = NULL; |
310 | port->client_ops = &tty_port_default_client_ops; |
311 | serdev_controller_put(ctrl); |
312 | |
313 | return ERR_PTR(error: ret); |
314 | } |
315 | |
316 | int serdev_tty_port_unregister(struct tty_port *port) |
317 | { |
318 | struct serdev_controller *ctrl = port->client_data; |
319 | struct serport *serport = serdev_controller_get_drvdata(ctrl); |
320 | |
321 | if (!serport) |
322 | return -ENODEV; |
323 | |
324 | serdev_controller_remove(ctrl); |
325 | port->client_data = NULL; |
326 | port->client_ops = &tty_port_default_client_ops; |
327 | serdev_controller_put(ctrl); |
328 | |
329 | return 0; |
330 | } |
331 | |