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/iopoll.h>
11 : #include <linux/uaccess.h>
12 : #include <linux/termios.h>
13 : #include <linux/delay.h>
14 :
15 : struct serdev_controller;
16 : struct serdev_device;
17 :
18 : /*
19 : * serdev device structures
20 : */
21 :
22 : /**
23 : * struct serdev_device_ops - Callback operations for a serdev device
24 : * @receive_buf: Function called with data received from device;
25 : * returns number of bytes accepted; may sleep.
26 : * @write_wakeup: Function called when ready to transmit more data; must
27 : * not sleep.
28 : */
29 : struct serdev_device_ops {
30 : int (*receive_buf)(struct serdev_device *, const unsigned char *, size_t);
31 : void (*write_wakeup)(struct serdev_device *);
32 : };
33 :
34 : /**
35 : * struct serdev_device - Basic representation of an serdev device
36 : * @dev: Driver model representation of the device.
37 : * @nr: Device number on serdev bus.
38 : * @ctrl: serdev controller managing this device.
39 : * @ops: Device operations.
40 : * @write_comp Completion used by serdev_device_write() internally
41 : * @write_lock Lock to serialize access when writing data
42 : */
43 : struct serdev_device {
44 : struct device dev;
45 : int nr;
46 : struct serdev_controller *ctrl;
47 : const struct serdev_device_ops *ops;
48 : struct completion write_comp;
49 : struct mutex write_lock;
50 : };
51 :
52 : static inline struct serdev_device *to_serdev_device(struct device *d)
53 : {
54 : return container_of(d, struct serdev_device, dev);
55 : }
56 :
57 : /**
58 : * struct serdev_device_driver - serdev slave device driver
59 : * @driver: serdev device drivers should initialize name field of this
60 : * structure.
61 : * @probe: binds this driver to a serdev device.
62 : * @remove: unbinds this driver from the serdev device.
63 : */
64 : struct serdev_device_driver {
65 : struct device_driver driver;
66 : int (*probe)(struct serdev_device *);
67 : void (*remove)(struct serdev_device *);
68 : };
69 :
70 : static inline struct serdev_device_driver *to_serdev_device_driver(struct device_driver *d)
71 : {
72 : return container_of(d, struct serdev_device_driver, driver);
73 : }
74 :
75 : enum serdev_parity {
76 : SERDEV_PARITY_NONE,
77 : SERDEV_PARITY_EVEN,
78 : SERDEV_PARITY_ODD,
79 : };
80 :
81 : /*
82 : * serdev controller structures
83 : */
84 : struct serdev_controller_ops {
85 : int (*write_buf)(struct serdev_controller *, const unsigned char *, size_t);
86 : void (*write_flush)(struct serdev_controller *);
87 : int (*write_room)(struct serdev_controller *);
88 : int (*open)(struct serdev_controller *);
89 : void (*close)(struct serdev_controller *);
90 : void (*set_flow_control)(struct serdev_controller *, bool);
91 : int (*set_parity)(struct serdev_controller *, enum serdev_parity);
92 : unsigned int (*set_baudrate)(struct serdev_controller *, unsigned int);
93 : void (*wait_until_sent)(struct serdev_controller *, long);
94 : int (*get_tiocm)(struct serdev_controller *);
95 : int (*set_tiocm)(struct serdev_controller *, unsigned int, unsigned int);
96 : int (*break_ctl)(struct serdev_controller *ctrl, unsigned int break_state);
97 : };
98 :
99 : /**
100 : * struct serdev_controller - interface to the serdev controller
101 : * @dev: Driver model representation of the device.
102 : * @nr: number identifier for this controller/bus.
103 : * @serdev: Pointer to slave device for this controller.
104 : * @ops: Controller operations.
105 : */
106 : struct serdev_controller {
107 : struct device dev;
108 : unsigned int nr;
109 : struct serdev_device *serdev;
110 : const struct serdev_controller_ops *ops;
111 : };
112 :
113 : static inline struct serdev_controller *to_serdev_controller(struct device *d)
114 : {
115 : return container_of(d, struct serdev_controller, dev);
116 : }
117 :
118 : static inline void *serdev_device_get_drvdata(const struct serdev_device *serdev)
119 : {
120 : return dev_get_drvdata(&serdev->dev);
121 : }
122 :
123 : static inline void serdev_device_set_drvdata(struct serdev_device *serdev, void *data)
124 : {
125 : dev_set_drvdata(&serdev->dev, data);
126 : }
127 :
128 : /**
129 : * serdev_device_put() - decrement serdev device refcount
130 : * @serdev serdev device.
131 : */
132 : static inline void serdev_device_put(struct serdev_device *serdev)
133 : {
134 : if (serdev)
135 : put_device(&serdev->dev);
136 : }
137 :
138 : static inline void serdev_device_set_client_ops(struct serdev_device *serdev,
139 : const struct serdev_device_ops *ops)
140 : {
141 : serdev->ops = ops;
142 : }
143 :
144 : static inline
145 : void *serdev_controller_get_drvdata(const struct serdev_controller *ctrl)
146 : {
147 : return ctrl ? dev_get_drvdata(&ctrl->dev) : NULL;
148 : }
149 :
150 : static inline void serdev_controller_set_drvdata(struct serdev_controller *ctrl,
151 : void *data)
152 : {
153 : dev_set_drvdata(&ctrl->dev, data);
154 : }
155 :
156 : /**
157 : * serdev_controller_put() - decrement controller refcount
158 : * @ctrl serdev controller.
159 : */
160 : static inline void serdev_controller_put(struct serdev_controller *ctrl)
161 : {
162 : if (ctrl)
163 : put_device(&ctrl->dev);
164 : }
165 :
166 : struct serdev_device *serdev_device_alloc(struct serdev_controller *);
167 : int serdev_device_add(struct serdev_device *);
168 : void serdev_device_remove(struct serdev_device *);
169 :
170 : struct serdev_controller *serdev_controller_alloc(struct device *, size_t);
171 : int serdev_controller_add(struct serdev_controller *);
172 : void serdev_controller_remove(struct serdev_controller *);
173 :
174 : static inline void serdev_controller_write_wakeup(struct serdev_controller *ctrl)
175 : {
176 : struct serdev_device *serdev = ctrl->serdev;
177 :
178 : if (!serdev || !serdev->ops->write_wakeup)
179 : return;
180 :
181 : serdev->ops->write_wakeup(serdev);
182 : }
183 :
184 : static inline int serdev_controller_receive_buf(struct serdev_controller *ctrl,
185 : const unsigned char *data,
186 : size_t count)
187 : {
188 : struct serdev_device *serdev = ctrl->serdev;
189 :
190 : if (!serdev || !serdev->ops->receive_buf)
191 : return 0;
192 :
193 : return serdev->ops->receive_buf(serdev, data, count);
194 : }
195 :
196 : #if IS_ENABLED(CONFIG_SERIAL_DEV_BUS)
197 :
198 : int serdev_device_open(struct serdev_device *);
199 : void serdev_device_close(struct serdev_device *);
200 : int devm_serdev_device_open(struct device *, struct serdev_device *);
201 : unsigned int serdev_device_set_baudrate(struct serdev_device *, unsigned int);
202 : void serdev_device_set_flow_control(struct serdev_device *, bool);
203 : int serdev_device_write_buf(struct serdev_device *, const unsigned char *, size_t);
204 : void serdev_device_wait_until_sent(struct serdev_device *, long);
205 : int serdev_device_get_tiocm(struct serdev_device *);
206 : int serdev_device_set_tiocm(struct serdev_device *, int, int);
207 : int serdev_device_break_ctl(struct serdev_device *serdev, int break_state);
208 : void serdev_device_write_wakeup(struct serdev_device *);
209 : int serdev_device_write(struct serdev_device *, const unsigned char *, size_t, long);
210 : void serdev_device_write_flush(struct serdev_device *);
211 : int serdev_device_write_room(struct serdev_device *);
212 :
213 : /*
214 : * serdev device driver functions
215 : */
216 : int __serdev_device_driver_register(struct serdev_device_driver *, struct module *);
217 : #define serdev_device_driver_register(sdrv) \
218 : __serdev_device_driver_register(sdrv, THIS_MODULE)
219 :
220 : /**
221 : * serdev_device_driver_unregister() - unregister an serdev client driver
222 : * @sdrv: the driver to unregister
223 : */
224 : static inline void serdev_device_driver_unregister(struct serdev_device_driver *sdrv)
225 : {
226 : if (sdrv)
227 : driver_unregister(&sdrv->driver);
228 : }
229 :
230 : #define module_serdev_device_driver(__serdev_device_driver) \
231 : module_driver(__serdev_device_driver, serdev_device_driver_register, \
232 : serdev_device_driver_unregister)
233 :
234 : #else
235 :
236 : static inline int serdev_device_open(struct serdev_device *sdev)
237 : {
238 : return -ENODEV;
239 : }
240 : static inline void serdev_device_close(struct serdev_device *sdev) {}
241 : static inline unsigned int serdev_device_set_baudrate(struct serdev_device *sdev, unsigned int baudrate)
242 : {
243 : return 0;
244 : }
245 : static inline void serdev_device_set_flow_control(struct serdev_device *sdev, bool enable) {}
246 : static inline int serdev_device_write_buf(struct serdev_device *serdev,
247 : const unsigned char *buf,
248 : size_t count)
249 : {
250 : return -ENODEV;
251 : }
252 : static inline void serdev_device_wait_until_sent(struct serdev_device *sdev, long timeout) {}
253 : static inline int serdev_device_get_tiocm(struct serdev_device *serdev)
254 : {
255 : return -EOPNOTSUPP;
256 : }
257 : static inline int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear)
258 : {
259 : return -EOPNOTSUPP;
260 : }
261 : static inline int serdev_device_break_ctl(struct serdev_device *serdev, int break_state)
262 : {
263 : return -EOPNOTSUPP;
264 : }
265 : static 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 : }
270 : static inline void serdev_device_write_flush(struct serdev_device *sdev) {}
271 : static 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 :
281 : static 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 :
287 : static inline int serdev_device_wait_for_cts(struct serdev_device *serdev, bool state, int timeout_ms)
288 : {
289 : bool signal;
290 :
291 : return readx_poll_timeout(serdev_device_get_cts, serdev, signal, signal == state,
292 : 2000, timeout_ms * 1000);
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 : 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 0 : return ERR_PTR(-ENODEV);
323 : }
324 : static inline int serdev_tty_port_unregister(struct tty_port *port)
325 : {
326 : return -ENODEV;
327 : }
328 : #endif /* CONFIG_SERIAL_DEV_CTRL_TTYPORT */
329 :
330 : struct acpi_resource;
331 : struct acpi_resource_uart_serialbus;
332 :
333 : #ifdef CONFIG_ACPI
334 : bool serdev_acpi_get_uart_resource(struct acpi_resource *ares,
335 : struct acpi_resource_uart_serialbus **uart);
336 : #else
337 : static inline bool serdev_acpi_get_uart_resource(struct acpi_resource *ares,
338 : struct acpi_resource_uart_serialbus **uart)
339 : {
340 : return false;
341 : }
342 : #endif /* CONFIG_ACPI */
343 :
344 : #endif /*_LINUX_SERDEV_H */
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