projects/linux·blob v5.6-rc4 · refs

330 lines · 9.5 KiB

1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright (C) 2016-2017 Linaro Ltd., Rob Herring <[email protected]>
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
13struct serdev_controller;
14struct 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 */
27struct 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 */
41struct 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
50static 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 */
62struct serdev_device_driver {
63 struct device_driver driver;
64 int (*probe)(struct serdev_device *);
65 void (*remove)(struct serdev_device *);
66};
67
68static 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
73enum serdev_parity {
74 SERDEV_PARITY_NONE,
75 SERDEV_PARITY_EVEN,
76 SERDEV_PARITY_ODD,
77};
78
79/*
80 * serdev controller structures
81 */
82struct 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 */
103struct serdev_controller {
104 struct device dev;
105 unsigned int nr;
106 struct serdev_device *serdev;
107 const struct serdev_controller_ops *ops;
108};
109
110static inline struct serdev_controller *to_serdev_controller(struct device *d)
111{
112 return container_of(d, struct serdev_controller, dev);
113}
114
115static inline void *serdev_device_get_drvdata(const struct serdev_device *serdev)
116{
117 return dev_get_drvdata(&serdev->dev);
118}
119
120static 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 */
129static inline void serdev_device_put(struct serdev_device *serdev)
130{
131 if (serdev)
132 put_device(&serdev->dev);
133}
134
135static 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
141static inline
142void *serdev_controller_get_drvdata(const struct serdev_controller *ctrl)
143{
144 return ctrl ? dev_get_drvdata(&ctrl->dev) : NULL;
145}
146
147static 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 */
157static inline void serdev_controller_put(struct serdev_controller *ctrl)
158{
159 if (ctrl)
160 put_device(&ctrl->dev);
161}
162
163struct serdev_device *serdev_device_alloc(struct serdev_controller *);
164int serdev_device_add(struct serdev_device *);
165void serdev_device_remove(struct serdev_device *);
166
167struct serdev_controller *serdev_controller_alloc(struct device *, size_t);
168int serdev_controller_add(struct serdev_controller *);
169void serdev_controller_remove(struct serdev_controller *);
170
171static 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
181static 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
195int serdev_device_open(struct serdev_device *);
196void serdev_device_close(struct serdev_device *);
197int devm_serdev_device_open(struct device *, struct serdev_device *);
198unsigned int serdev_device_set_baudrate(struct serdev_device *, unsigned int);
199void serdev_device_set_flow_control(struct serdev_device *, bool);
200int serdev_device_write_buf(struct serdev_device *, const unsigned char *, size_t);
201void serdev_device_wait_until_sent(struct serdev_device *, long);
202int serdev_device_get_tiocm(struct serdev_device *);
203int serdev_device_set_tiocm(struct serdev_device *, int, int);
204void serdev_device_write_wakeup(struct serdev_device *);
205int serdev_device_write(struct serdev_device *, const unsigned char *, size_t, long);
206void serdev_device_write_flush(struct serdev_device *);
207int serdev_device_write_room(struct serdev_device *);
208
209/*
210 * serdev device driver functions
211 */
212int __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 */
220static 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
232static inline int serdev_device_open(struct serdev_device *sdev)
233{
234 return -ENODEV;
235}
236static inline void serdev_device_close(struct serdev_device *sdev) {}
237static inline unsigned int serdev_device_set_baudrate(struct serdev_device *sdev, unsigned int baudrate)
238{
239 return 0;
240}
241static inline void serdev_device_set_flow_control(struct serdev_device *sdev, bool enable) {}
242static inline int serdev_device_write_buf(struct serdev_device *serdev,
243 const unsigned char *buf,
244 size_t count)
245{
246 return -ENODEV;
247}
248static inline void serdev_device_wait_until_sent(struct serdev_device *sdev, long timeout) {}
249static inline int serdev_device_get_tiocm(struct serdev_device *serdev)
250{
251 return -ENOTSUPP;
252}
253static inline int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear)
254{
255 return -ENOTSUPP;
256}
257static 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}
262static inline void serdev_device_write_flush(struct serdev_device *sdev) {}
263static 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
273static 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
279static 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
295static 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
303int serdev_device_set_parity(struct serdev_device *serdev,
304 enum serdev_parity parity);
305
306/*
307 * serdev hooks into TTY core
308 */
309struct tty_port;
310struct tty_driver;
311
312#ifdef CONFIG_SERIAL_DEV_CTRL_TTYPORT
313struct device *serdev_tty_port_register(struct tty_port *port,
314 struct device *parent,
315 struct tty_driver *drv, int idx);
316int serdev_tty_port_unregister(struct tty_port *port);
317#else
318static inline struct device *serdev_tty_port_register(struct tty_port *port,
319 struct device *parent,
320 struct tty_driver *drv, int idx)
321{
322 return ERR_PTR(-ENODEV);
323}
324static inline int serdev_tty_port_unregister(struct tty_port *port)
325{
326 return -ENODEV;
327}
328#endif /* CONFIG_SERIAL_DEV_CTRL_TTYPORT */
329
330#endif /*_LINUX_SERDEV_H */