1/*
2 * Copyright (C) 2016-2017 Linaro Ltd., Rob Herring <robh@kernel.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 and
6 * only version 2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 */
13#ifndef _LINUX_SERDEV_H
14#define _LINUX_SERDEV_H
15
16#include <linux/types.h>
17#include <linux/device.h>
18#include <linux/termios.h>
19#include <linux/delay.h>
20
21struct serdev_controller;
22struct serdev_device;
23
24/*
25 * serdev device structures
26 */
27
28/**
29 * struct serdev_device_ops - Callback operations for a serdev device
30 * @receive_buf: Function called with data received from device;
31 * returns number of bytes accepted; may sleep.
32 * @write_wakeup: Function called when ready to transmit more data; must
33 * not sleep.
34 */
35struct serdev_device_ops {
36 int (*receive_buf)(struct serdev_device *, const unsigned char *, size_t);
37 void (*write_wakeup)(struct serdev_device *);
38};
39
40/**
41 * struct serdev_device - Basic representation of an serdev device
42 * @dev: Driver model representation of the device.
43 * @nr: Device number on serdev bus.
44 * @ctrl: serdev controller managing this device.
45 * @ops: Device operations.
46 * @write_comp Completion used by serdev_device_write() internally
47 * @write_lock Lock to serialize access when writing data
48 */
49struct serdev_device {
50 struct device dev;
51 int nr;
52 struct serdev_controller *ctrl;
53 const struct serdev_device_ops *ops;
54 struct completion write_comp;
55 struct mutex write_lock;
56};
57
58static inline struct serdev_device *to_serdev_device(struct device *d)
59{
60 return container_of(d, struct serdev_device, dev);
61}
62
63/**
64 * struct serdev_device_driver - serdev slave device driver
65 * @driver: serdev device drivers should initialize name field of this
66 * structure.
67 * @probe: binds this driver to a serdev device.
68 * @remove: unbinds this driver from the serdev device.
69 */
70struct serdev_device_driver {
71 struct device_driver driver;
72 int (*probe)(struct serdev_device *);
73 void (*remove)(struct serdev_device *);
74};
75
76static inline struct serdev_device_driver *to_serdev_device_driver(struct device_driver *d)
77{
78 return container_of(d, struct serdev_device_driver, driver);
79}
80
81enum serdev_parity {
82 SERDEV_PARITY_NONE,
83 SERDEV_PARITY_EVEN,
84 SERDEV_PARITY_ODD,
85};
86
87/*
88 * serdev controller structures
89 */
90struct serdev_controller_ops {
91 int (*write_buf)(struct serdev_controller *, const unsigned char *, size_t);
92 void (*write_flush)(struct serdev_controller *);
93 int (*write_room)(struct serdev_controller *);
94 int (*open)(struct serdev_controller *);
95 void (*close)(struct serdev_controller *);
96 void (*set_flow_control)(struct serdev_controller *, bool);
97 int (*set_parity)(struct serdev_controller *, enum serdev_parity);
98 unsigned int (*set_baudrate)(struct serdev_controller *, unsigned int);
99 void (*wait_until_sent)(struct serdev_controller *, long);
100 int (*get_tiocm)(struct serdev_controller *);
101 int (*set_tiocm)(struct serdev_controller *, unsigned int, unsigned int);
102};
103
104/**
105 * struct serdev_controller - interface to the serdev controller
106 * @dev: Driver model representation of the device.
107 * @nr: number identifier for this controller/bus.
108 * @serdev: Pointer to slave device for this controller.
109 * @ops: Controller operations.
110 */
111struct serdev_controller {
112 struct device dev;
113 unsigned int nr;
114 struct serdev_device *serdev;
115 const struct serdev_controller_ops *ops;
116};
117
118static inline struct serdev_controller *to_serdev_controller(struct device *d)
119{
120 return container_of(d, struct serdev_controller, dev);
121}
122
123static inline void *serdev_device_get_drvdata(const struct serdev_device *serdev)
124{
125 return dev_get_drvdata(&serdev->dev);
126}
127
128static inline void serdev_device_set_drvdata(struct serdev_device *serdev, void *data)
129{
130 dev_set_drvdata(&serdev->dev, data);
131}
132
133/**
134 * serdev_device_put() - decrement serdev device refcount
135 * @serdev serdev device.
136 */
137static inline void serdev_device_put(struct serdev_device *serdev)
138{
139 if (serdev)
140 put_device(&serdev->dev);
141}
142
143static inline void serdev_device_set_client_ops(struct serdev_device *serdev,
144 const struct serdev_device_ops *ops)
145{
146 serdev->ops = ops;
147}
148
149static inline
150void *serdev_controller_get_drvdata(const struct serdev_controller *ctrl)
151{
152 return ctrl ? dev_get_drvdata(&ctrl->dev) : NULL;
153}
154
155static inline void serdev_controller_set_drvdata(struct serdev_controller *ctrl,
156 void *data)
157{
158 dev_set_drvdata(&ctrl->dev, data);
159}
160
161/**
162 * serdev_controller_put() - decrement controller refcount
163 * @ctrl serdev controller.
164 */
165static inline void serdev_controller_put(struct serdev_controller *ctrl)
166{
167 if (ctrl)
168 put_device(&ctrl->dev);
169}
170
171struct serdev_device *serdev_device_alloc(struct serdev_controller *);
172int serdev_device_add(struct serdev_device *);
173void serdev_device_remove(struct serdev_device *);
174
175struct serdev_controller *serdev_controller_alloc(struct device *, size_t);
176int serdev_controller_add(struct serdev_controller *);
177void serdev_controller_remove(struct serdev_controller *);
178
179static inline void serdev_controller_write_wakeup(struct serdev_controller *ctrl)
180{
181 struct serdev_device *serdev = ctrl->serdev;
182
183 if (!serdev || !serdev->ops->write_wakeup)
184 return;
185
186 serdev->ops->write_wakeup(serdev);
187}
188
189static inline int serdev_controller_receive_buf(struct serdev_controller *ctrl,
190 const unsigned char *data,
191 size_t count)
192{
193 struct serdev_device *serdev = ctrl->serdev;
194
195 if (!serdev || !serdev->ops->receive_buf)
196 return 0;
197
198 return serdev->ops->receive_buf(serdev, data, count);
199}
200
201#if IS_ENABLED(CONFIG_SERIAL_DEV_BUS)
202
203int serdev_device_open(struct serdev_device *);
204void serdev_device_close(struct serdev_device *);
205int devm_serdev_device_open(struct device *, struct serdev_device *);
206unsigned int serdev_device_set_baudrate(struct serdev_device *, unsigned int);
207void serdev_device_set_flow_control(struct serdev_device *, bool);
208int serdev_device_write_buf(struct serdev_device *, const unsigned char *, size_t);
209void serdev_device_wait_until_sent(struct serdev_device *, long);
210int serdev_device_get_tiocm(struct serdev_device *);
211int serdev_device_set_tiocm(struct serdev_device *, int, int);
212void serdev_device_write_wakeup(struct serdev_device *);
213int serdev_device_write(struct serdev_device *, const unsigned char *, size_t, long);
214void serdev_device_write_flush(struct serdev_device *);
215int serdev_device_write_room(struct serdev_device *);
216
217/*
218 * serdev device driver functions
219 */
220int __serdev_device_driver_register(struct serdev_device_driver *, struct module *);
221#define serdev_device_driver_register(sdrv) \
222 __serdev_device_driver_register(sdrv, THIS_MODULE)
223
224/**
225 * serdev_device_driver_unregister() - unregister an serdev client driver
226 * @sdrv: the driver to unregister
227 */
228static inline void serdev_device_driver_unregister(struct serdev_device_driver *sdrv)
229{
230 if (sdrv)
231 driver_unregister(&sdrv->driver);
232}
233
234#define module_serdev_device_driver(__serdev_device_driver) \
235 module_driver(__serdev_device_driver, serdev_device_driver_register, \
236 serdev_device_driver_unregister)
237
238#else
239
240static inline int serdev_device_open(struct serdev_device *sdev)
241{
242 return -ENODEV;
243}
244static inline void serdev_device_close(struct serdev_device *sdev) {}
245static inline unsigned int serdev_device_set_baudrate(struct serdev_device *sdev, unsigned int baudrate)
246{
247 return 0;
248}
249static inline void serdev_device_set_flow_control(struct serdev_device *sdev, bool enable) {}
250static inline int serdev_device_write_buf(struct serdev_device *serdev,
251 const unsigned char *buf,
252 size_t count)
253{
254 return -ENODEV;
255}
256static inline void serdev_device_wait_until_sent(struct serdev_device *sdev, long timeout) {}
257static inline int serdev_device_get_tiocm(struct serdev_device *serdev)
258{
259 return -ENOTSUPP;
260}
261static inline int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear)
262{
263 return -ENOTSUPP;
264}
265static inline int serdev_device_write(struct serdev_device *sdev, const unsigned char *buf,
266 size_t count, unsigned long timeout)
267{
268 return -ENODEV;
269}
270static inline void serdev_device_write_flush(struct serdev_device *sdev) {}
271static inline int serdev_device_write_room(struct serdev_device *sdev)
272{
273 return 0;
274}
275
276#define serdev_device_driver_register(x)
277#define serdev_device_driver_unregister(x)
278
279#endif /* CONFIG_SERIAL_DEV_BUS */
280
281static inline bool serdev_device_get_cts(struct serdev_device *serdev)
282{
283 int status = serdev_device_get_tiocm(serdev);
284 return !!(status & TIOCM_CTS);
285}
286
287static inline int serdev_device_wait_for_cts(struct serdev_device *serdev, bool state, int timeout_ms)
288{
289 unsigned long timeout;
290 bool signal;
291
292 timeout = jiffies + msecs_to_jiffies(timeout_ms);
293 while (time_is_after_jiffies(timeout)) {
294 signal = serdev_device_get_cts(serdev);
295 if (signal == state)
296 return 0;
297 usleep_range(1000, 2000);
298 }
299
300 return -ETIMEDOUT;
301}
302
303static inline int serdev_device_set_rts(struct serdev_device *serdev, bool enable)
304{
305 if (enable)
306 return serdev_device_set_tiocm(serdev, TIOCM_RTS, 0);
307 else
308 return serdev_device_set_tiocm(serdev, 0, TIOCM_RTS);
309}
310
311int serdev_device_set_parity(struct serdev_device *serdev,
312 enum serdev_parity parity);
313
314/*
315 * serdev hooks into TTY core
316 */
317struct tty_port;
318struct tty_driver;
319
320#ifdef CONFIG_SERIAL_DEV_CTRL_TTYPORT
321struct device *serdev_tty_port_register(struct tty_port *port,
322 struct device *parent,
323 struct tty_driver *drv, int idx);
324int serdev_tty_port_unregister(struct tty_port *port);
325#else
326static inline struct device *serdev_tty_port_register(struct tty_port *port,
327 struct device *parent,
328 struct tty_driver *drv, int idx)
329{
330 return ERR_PTR(-ENODEV);
331}
332static inline int serdev_tty_port_unregister(struct tty_port *port)
333{
334 return -ENODEV;
335}
336#endif /* CONFIG_SERIAL_DEV_CTRL_TTYPORT */
337
338#endif /*_LINUX_SERDEV_H */
339