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 : };
97 :
98 : /**
99 : * struct serdev_controller - interface to the serdev controller
100 : * @dev: Driver model representation of the device.
101 : * @nr: number identifier for this controller/bus.
102 : * @serdev: Pointer to slave device for this controller.
103 : * @ops: Controller operations.
104 : */
105 : struct serdev_controller {
106 : struct device dev;
107 : unsigned int nr;
108 : struct serdev_device *serdev;
109 : const struct serdev_controller_ops *ops;
110 : };
111 :
112 : static inline struct serdev_controller *to_serdev_controller(struct device *d)
113 : {
114 : return container_of(d, struct serdev_controller, dev);
115 : }
116 :
117 : static inline void *serdev_device_get_drvdata(const struct serdev_device *serdev)
118 : {
119 : return dev_get_drvdata(&serdev->dev);
120 : }
121 :
122 : static inline void serdev_device_set_drvdata(struct serdev_device *serdev, void *data)
123 : {
124 : dev_set_drvdata(&serdev->dev, data);
125 : }
126 :
127 : /**
128 : * serdev_device_put() - decrement serdev device refcount
129 : * @serdev serdev device.
130 : */
131 : static inline void serdev_device_put(struct serdev_device *serdev)
132 : {
133 : if (serdev)
134 : put_device(&serdev->dev);
135 : }
136 :
137 : static inline void serdev_device_set_client_ops(struct serdev_device *serdev,
138 : const struct serdev_device_ops *ops)
139 : {
140 : serdev->ops = ops;
141 : }
142 :
143 : static inline
144 : void *serdev_controller_get_drvdata(const struct serdev_controller *ctrl)
145 : {
146 : return ctrl ? dev_get_drvdata(&ctrl->dev) : NULL;
147 : }
148 :
149 : static inline void serdev_controller_set_drvdata(struct serdev_controller *ctrl,
150 : void *data)
151 : {
152 : dev_set_drvdata(&ctrl->dev, data);
153 : }
154 :
155 : /**
156 : * serdev_controller_put() - decrement controller refcount
157 : * @ctrl serdev controller.
158 : */
159 : static inline void serdev_controller_put(struct serdev_controller *ctrl)
160 : {
161 : if (ctrl)
162 : put_device(&ctrl->dev);
163 : }
164 :
165 : struct serdev_device *serdev_device_alloc(struct serdev_controller *);
166 : int serdev_device_add(struct serdev_device *);
167 : void serdev_device_remove(struct serdev_device *);
168 :
169 : struct serdev_controller *serdev_controller_alloc(struct device *, size_t);
170 : int serdev_controller_add(struct serdev_controller *);
171 : void serdev_controller_remove(struct serdev_controller *);
172 :
173 : static inline void serdev_controller_write_wakeup(struct serdev_controller *ctrl)
174 : {
175 : struct serdev_device *serdev = ctrl->serdev;
176 :
177 : if (!serdev || !serdev->ops->write_wakeup)
178 : return;
179 :
180 : serdev->ops->write_wakeup(serdev);
181 : }
182 :
183 : static inline int serdev_controller_receive_buf(struct serdev_controller *ctrl,
184 : const unsigned char *data,
185 : size_t count)
186 : {
187 : struct serdev_device *serdev = ctrl->serdev;
188 :
189 : if (!serdev || !serdev->ops->receive_buf)
190 : return 0;
191 :
192 : return serdev->ops->receive_buf(serdev, data, count);
193 : }
194 :
195 : #if IS_ENABLED(CONFIG_SERIAL_DEV_BUS)
196 :
197 : int serdev_device_open(struct serdev_device *);
198 : void serdev_device_close(struct serdev_device *);
199 : int devm_serdev_device_open(struct device *, struct serdev_device *);
200 : unsigned int serdev_device_set_baudrate(struct serdev_device *, unsigned int);
201 : void serdev_device_set_flow_control(struct serdev_device *, bool);
202 : int serdev_device_write_buf(struct serdev_device *, const unsigned char *, size_t);
203 : void serdev_device_wait_until_sent(struct serdev_device *, long);
204 : int serdev_device_get_tiocm(struct serdev_device *);
205 : int serdev_device_set_tiocm(struct serdev_device *, int, int);
206 : void serdev_device_write_wakeup(struct serdev_device *);
207 : int serdev_device_write(struct serdev_device *, const unsigned char *, size_t, long);
208 : void serdev_device_write_flush(struct serdev_device *);
209 : int serdev_device_write_room(struct serdev_device *);
210 :
211 : /*
212 : * serdev device driver functions
213 : */
214 : int __serdev_device_driver_register(struct serdev_device_driver *, struct module *);
215 : #define serdev_device_driver_register(sdrv) \
216 : __serdev_device_driver_register(sdrv, THIS_MODULE)
217 :
218 : /**
219 : * serdev_device_driver_unregister() - unregister an serdev client driver
220 : * @sdrv: the driver to unregister
221 : */
222 : static inline void serdev_device_driver_unregister(struct serdev_device_driver *sdrv)
223 : {
224 : if (sdrv)
225 : driver_unregister(&sdrv->driver);
226 : }
227 :
228 : #define module_serdev_device_driver(__serdev_device_driver) \
229 : module_driver(__serdev_device_driver, serdev_device_driver_register, \
230 : serdev_device_driver_unregister)
231 :
232 : #else
233 :
234 : static inline int serdev_device_open(struct serdev_device *sdev)
235 : {
236 : return -ENODEV;
237 : }
238 : static inline void serdev_device_close(struct serdev_device *sdev) {}
239 : static inline unsigned int serdev_device_set_baudrate(struct serdev_device *sdev, unsigned int baudrate)
240 : {
241 : return 0;
242 : }
243 : static inline void serdev_device_set_flow_control(struct serdev_device *sdev, bool enable) {}
244 : static inline int serdev_device_write_buf(struct serdev_device *serdev,
245 : const unsigned char *buf,
246 : size_t count)
247 : {
248 : return -ENODEV;
249 : }
250 : static inline void serdev_device_wait_until_sent(struct serdev_device *sdev, long timeout) {}
251 : static inline int serdev_device_get_tiocm(struct serdev_device *serdev)
252 : {
253 : return -ENOTSUPP;
254 : }
255 : static inline int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear)
256 : {
257 : return -ENOTSUPP;
258 : }
259 : static inline int serdev_device_write(struct serdev_device *sdev, const unsigned char *buf,
260 : size_t count, unsigned long timeout)
261 : {
262 : return -ENODEV;
263 : }
264 : static inline void serdev_device_write_flush(struct serdev_device *sdev) {}
265 : static inline int serdev_device_write_room(struct serdev_device *sdev)
266 : {
267 : return 0;
268 : }
269 :
270 : #define serdev_device_driver_register(x)
271 : #define serdev_device_driver_unregister(x)
272 :
273 : #endif /* CONFIG_SERIAL_DEV_BUS */
274 :
275 : static inline bool serdev_device_get_cts(struct serdev_device *serdev)
276 : {
277 : int status = serdev_device_get_tiocm(serdev);
278 : return !!(status & TIOCM_CTS);
279 : }
280 :
281 : static inline int serdev_device_wait_for_cts(struct serdev_device *serdev, bool state, int timeout_ms)
282 : {
283 : bool signal;
284 :
285 : return readx_poll_timeout(serdev_device_get_cts, serdev, signal, signal == state,
286 : 2000, timeout_ms * 1000);
287 : }
288 :
289 : static inline int serdev_device_set_rts(struct serdev_device *serdev, bool enable)
290 : {
291 : if (enable)
292 : return serdev_device_set_tiocm(serdev, TIOCM_RTS, 0);
293 : else
294 : return serdev_device_set_tiocm(serdev, 0, TIOCM_RTS);
295 : }
296 :
297 : int serdev_device_set_parity(struct serdev_device *serdev,
298 : enum serdev_parity parity);
299 :
300 : /*
301 : * serdev hooks into TTY core
302 : */
303 : struct tty_port;
304 : struct tty_driver;
305 :
306 : #ifdef CONFIG_SERIAL_DEV_CTRL_TTYPORT
307 : struct device *serdev_tty_port_register(struct tty_port *port,
308 : struct device *parent,
309 : struct tty_driver *drv, int idx);
310 : int serdev_tty_port_unregister(struct tty_port *port);
311 : #else
312 : static inline struct device *serdev_tty_port_register(struct tty_port *port,
313 : struct device *parent,
314 : struct tty_driver *drv, int idx)
315 : {
316 0 : return ERR_PTR(-ENODEV);
317 : }
318 : static inline int serdev_tty_port_unregister(struct tty_port *port)
319 : {
320 : return -ENODEV;
321 : }
322 : #endif /* CONFIG_SERIAL_DEV_CTRL_TTYPORT */
323 :
324 : struct acpi_resource;
325 : struct acpi_resource_uart_serialbus;
326 :
327 : #ifdef CONFIG_ACPI
328 : bool serdev_acpi_get_uart_resource(struct acpi_resource *ares,
329 : struct acpi_resource_uart_serialbus **uart);
330 : #else
331 : static inline bool serdev_acpi_get_uart_resource(struct acpi_resource *ares,
332 : struct acpi_resource_uart_serialbus **uart)
333 : {
334 : return false;
335 : }
336 : #endif /* CONFIG_ACPI */
337 :
338 : #endif /*_LINUX_SERDEV_H */
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