Line data Source code
1 : /* SPDX-License-Identifier: GPL-2.0-only */
2 : /*
3 : * Copyright (C) 2016-2017 Linaro Ltd., Rob Herring <robh@kernel.org>
4 : */
5 : #ifndef _LINUX_SERDEV_H
6 : #define _LINUX_SERDEV_H
7 :
8 : #include <linux/types.h>
9 : #include <linux/device.h>
10 : #include <linux/termios.h>
11 : #include <linux/delay.h>
12 :
13 : struct serdev_controller;
14 : struct serdev_device;
15 :
16 : /*
17 : * serdev device structures
18 : */
19 :
20 : /**
21 : * struct serdev_device_ops - Callback operations for a serdev device
22 : * @receive_buf: Function called with data received from device;
23 : * returns number of bytes accepted; may sleep.
24 : * @write_wakeup: Function called when ready to transmit more data; must
25 : * not sleep.
26 : */
27 : struct serdev_device_ops {
28 : int (*receive_buf)(struct serdev_device *, const unsigned char *, size_t);
29 : void (*write_wakeup)(struct serdev_device *);
30 : };
31 :
32 : /**
33 : * struct serdev_device - Basic representation of an serdev device
34 : * @dev: Driver model representation of the device.
35 : * @nr: Device number on serdev bus.
36 : * @ctrl: serdev controller managing this device.
37 : * @ops: Device operations.
38 : * @write_comp Completion used by serdev_device_write() internally
39 : * @write_lock Lock to serialize access when writing data
40 : */
41 : struct serdev_device {
42 : struct device dev;
43 : int nr;
44 : struct serdev_controller *ctrl;
45 : const struct serdev_device_ops *ops;
46 : struct completion write_comp;
47 : struct mutex write_lock;
48 : };
49 :
50 : static inline struct serdev_device *to_serdev_device(struct device *d)
51 : {
52 : return container_of(d, struct serdev_device, dev);
53 : }
54 :
55 : /**
56 : * struct serdev_device_driver - serdev slave device driver
57 : * @driver: serdev device drivers should initialize name field of this
58 : * structure.
59 : * @probe: binds this driver to a serdev device.
60 : * @remove: unbinds this driver from the serdev device.
61 : */
62 : struct serdev_device_driver {
63 : struct device_driver driver;
64 : int (*probe)(struct serdev_device *);
65 : void (*remove)(struct serdev_device *);
66 : };
67 :
68 : static inline struct serdev_device_driver *to_serdev_device_driver(struct device_driver *d)
69 : {
70 : return container_of(d, struct serdev_device_driver, driver);
71 : }
72 :
73 : enum serdev_parity {
74 : SERDEV_PARITY_NONE,
75 : SERDEV_PARITY_EVEN,
76 : SERDEV_PARITY_ODD,
77 : };
78 :
79 : /*
80 : * serdev controller structures
81 : */
82 : struct serdev_controller_ops {
83 : int (*write_buf)(struct serdev_controller *, const unsigned char *, size_t);
84 : void (*write_flush)(struct serdev_controller *);
85 : int (*write_room)(struct serdev_controller *);
86 : int (*open)(struct serdev_controller *);
87 : void (*close)(struct serdev_controller *);
88 : void (*set_flow_control)(struct serdev_controller *, bool);
89 : int (*set_parity)(struct serdev_controller *, enum serdev_parity);
90 : unsigned int (*set_baudrate)(struct serdev_controller *, unsigned int);
91 : void (*wait_until_sent)(struct serdev_controller *, long);
92 : int (*get_tiocm)(struct serdev_controller *);
93 : int (*set_tiocm)(struct serdev_controller *, unsigned int, unsigned int);
94 : };
95 :
96 : /**
97 : * struct serdev_controller - interface to the serdev controller
98 : * @dev: Driver model representation of the device.
99 : * @nr: number identifier for this controller/bus.
100 : * @serdev: Pointer to slave device for this controller.
101 : * @ops: Controller operations.
102 : */
103 : struct serdev_controller {
104 : struct device dev;
105 : unsigned int nr;
106 : struct serdev_device *serdev;
107 : const struct serdev_controller_ops *ops;
108 : };
109 :
110 : static inline struct serdev_controller *to_serdev_controller(struct device *d)
111 : {
112 : return container_of(d, struct serdev_controller, dev);
113 : }
114 :
115 : static inline void *serdev_device_get_drvdata(const struct serdev_device *serdev)
116 : {
117 : return dev_get_drvdata(&serdev->dev);
118 : }
119 :
120 : static inline void serdev_device_set_drvdata(struct serdev_device *serdev, void *data)
121 : {
122 : dev_set_drvdata(&serdev->dev, data);
123 : }
124 :
125 : /**
126 : * serdev_device_put() - decrement serdev device refcount
127 : * @serdev serdev device.
128 : */
129 : static inline void serdev_device_put(struct serdev_device *serdev)
130 : {
131 : if (serdev)
132 : put_device(&serdev->dev);
133 : }
134 :
135 : static inline void serdev_device_set_client_ops(struct serdev_device *serdev,
136 : const struct serdev_device_ops *ops)
137 : {
138 : serdev->ops = ops;
139 : }
140 :
141 : static inline
142 : void *serdev_controller_get_drvdata(const struct serdev_controller *ctrl)
143 : {
144 : return ctrl ? dev_get_drvdata(&ctrl->dev) : NULL;
145 : }
146 :
147 : static inline void serdev_controller_set_drvdata(struct serdev_controller *ctrl,
148 : void *data)
149 : {
150 : dev_set_drvdata(&ctrl->dev, data);
151 : }
152 :
153 : /**
154 : * serdev_controller_put() - decrement controller refcount
155 : * @ctrl serdev controller.
156 : */
157 : static inline void serdev_controller_put(struct serdev_controller *ctrl)
158 : {
159 : if (ctrl)
160 : put_device(&ctrl->dev);
161 : }
162 :
163 : struct serdev_device *serdev_device_alloc(struct serdev_controller *);
164 : int serdev_device_add(struct serdev_device *);
165 : void serdev_device_remove(struct serdev_device *);
166 :
167 : struct serdev_controller *serdev_controller_alloc(struct device *, size_t);
168 : int serdev_controller_add(struct serdev_controller *);
169 : void serdev_controller_remove(struct serdev_controller *);
170 :
171 : static inline void serdev_controller_write_wakeup(struct serdev_controller *ctrl)
172 : {
173 : struct serdev_device *serdev = ctrl->serdev;
174 :
175 : if (!serdev || !serdev->ops->write_wakeup)
176 : return;
177 :
178 : serdev->ops->write_wakeup(serdev);
179 : }
180 :
181 : static inline int serdev_controller_receive_buf(struct serdev_controller *ctrl,
182 : const unsigned char *data,
183 : size_t count)
184 : {
185 : struct serdev_device *serdev = ctrl->serdev;
186 :
187 : if (!serdev || !serdev->ops->receive_buf)
188 : return 0;
189 :
190 : return serdev->ops->receive_buf(serdev, data, count);
191 : }
192 :
193 : #if IS_ENABLED(CONFIG_SERIAL_DEV_BUS)
194 :
195 : int serdev_device_open(struct serdev_device *);
196 : void serdev_device_close(struct serdev_device *);
197 : int devm_serdev_device_open(struct device *, struct serdev_device *);
198 : unsigned int serdev_device_set_baudrate(struct serdev_device *, unsigned int);
199 : void serdev_device_set_flow_control(struct serdev_device *, bool);
200 : int serdev_device_write_buf(struct serdev_device *, const unsigned char *, size_t);
201 : void serdev_device_wait_until_sent(struct serdev_device *, long);
202 : int serdev_device_get_tiocm(struct serdev_device *);
203 : int serdev_device_set_tiocm(struct serdev_device *, int, int);
204 : void serdev_device_write_wakeup(struct serdev_device *);
205 : int serdev_device_write(struct serdev_device *, const unsigned char *, size_t, long);
206 : void serdev_device_write_flush(struct serdev_device *);
207 : int serdev_device_write_room(struct serdev_device *);
208 :
209 : /*
210 : * serdev device driver functions
211 : */
212 : int __serdev_device_driver_register(struct serdev_device_driver *, struct module *);
213 : #define serdev_device_driver_register(sdrv) \
214 : __serdev_device_driver_register(sdrv, THIS_MODULE)
215 :
216 : /**
217 : * serdev_device_driver_unregister() - unregister an serdev client driver
218 : * @sdrv: the driver to unregister
219 : */
220 : static inline void serdev_device_driver_unregister(struct serdev_device_driver *sdrv)
221 : {
222 : if (sdrv)
223 : driver_unregister(&sdrv->driver);
224 : }
225 :
226 : #define module_serdev_device_driver(__serdev_device_driver) \
227 : module_driver(__serdev_device_driver, serdev_device_driver_register, \
228 : serdev_device_driver_unregister)
229 :
230 : #else
231 :
232 : static inline int serdev_device_open(struct serdev_device *sdev)
233 : {
234 : return -ENODEV;
235 : }
236 : static inline void serdev_device_close(struct serdev_device *sdev) {}
237 : static inline unsigned int serdev_device_set_baudrate(struct serdev_device *sdev, unsigned int baudrate)
238 : {
239 : return 0;
240 : }
241 : static inline void serdev_device_set_flow_control(struct serdev_device *sdev, bool enable) {}
242 : static inline int serdev_device_write_buf(struct serdev_device *serdev,
243 : const unsigned char *buf,
244 : size_t count)
245 : {
246 : return -ENODEV;
247 : }
248 : static inline void serdev_device_wait_until_sent(struct serdev_device *sdev, long timeout) {}
249 : static inline int serdev_device_get_tiocm(struct serdev_device *serdev)
250 : {
251 : return -ENOTSUPP;
252 : }
253 : static inline int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear)
254 : {
255 : return -ENOTSUPP;
256 : }
257 : static inline int serdev_device_write(struct serdev_device *sdev, const unsigned char *buf,
258 : size_t count, unsigned long timeout)
259 : {
260 : return -ENODEV;
261 : }
262 : static inline void serdev_device_write_flush(struct serdev_device *sdev) {}
263 : static inline int serdev_device_write_room(struct serdev_device *sdev)
264 : {
265 : return 0;
266 : }
267 :
268 : #define serdev_device_driver_register(x)
269 : #define serdev_device_driver_unregister(x)
270 :
271 : #endif /* CONFIG_SERIAL_DEV_BUS */
272 :
273 : static inline bool serdev_device_get_cts(struct serdev_device *serdev)
274 : {
275 : int status = serdev_device_get_tiocm(serdev);
276 : return !!(status & TIOCM_CTS);
277 : }
278 :
279 : static inline int serdev_device_wait_for_cts(struct serdev_device *serdev, bool state, int timeout_ms)
280 : {
281 : unsigned long timeout;
282 : bool signal;
283 :
284 : timeout = jiffies + msecs_to_jiffies(timeout_ms);
285 : while (time_is_after_jiffies(timeout)) {
286 : signal = serdev_device_get_cts(serdev);
287 : if (signal == state)
288 : return 0;
289 : usleep_range(1000, 2000);
290 : }
291 :
292 : return -ETIMEDOUT;
293 : }
294 :
295 : static inline int serdev_device_set_rts(struct serdev_device *serdev, bool enable)
296 : {
297 : if (enable)
298 : return serdev_device_set_tiocm(serdev, TIOCM_RTS, 0);
299 : else
300 : return serdev_device_set_tiocm(serdev, 0, TIOCM_RTS);
301 : }
302 :
303 : int serdev_device_set_parity(struct serdev_device *serdev,
304 : enum serdev_parity parity);
305 :
306 : /*
307 : * serdev hooks into TTY core
308 : */
309 : struct tty_port;
310 : struct tty_driver;
311 :
312 : #ifdef CONFIG_SERIAL_DEV_CTRL_TTYPORT
313 : struct device *serdev_tty_port_register(struct tty_port *port,
314 : struct device *parent,
315 : struct tty_driver *drv, int idx);
316 : int serdev_tty_port_unregister(struct tty_port *port);
317 : #else
318 4 : static inline struct device *serdev_tty_port_register(struct tty_port *port,
319 : struct device *parent,
320 : struct tty_driver *drv, int idx)
321 : {
322 4 : return ERR_PTR(-ENODEV);
323 : }
324 0 : static inline int serdev_tty_port_unregister(struct tty_port *port)
325 : {
326 0 : return -ENODEV;
327 : }
328 : #endif /* CONFIG_SERIAL_DEV_CTRL_TTYPORT */
329 :
330 : #endif /*_LINUX_SERDEV_H */
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