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 size_t (*receive_buf)(struct serdev_device *, const u8 *, 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 ssize_t (*write_buf)(struct serdev_controller *, const u8 *, 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 * @host: Serial port hardware controller device
103 * @nr: number identifier for this controller/bus.
104 * @serdev: Pointer to slave device for this controller.
105 * @ops: Controller operations.
106 */
107 struct serdev_controller {
108 struct device dev;
109 struct device *host;
110 unsigned int nr;
111 struct serdev_device *serdev;
112 const struct serdev_controller_ops *ops;
113 };
114
115 static inline struct serdev_controller *to_serdev_controller(struct device *d)
116 {
117 return container_of(d, struct serdev_controller, dev);
118 }
119
120 static inline void *serdev_device_get_drvdata(const struct serdev_device *serdev)
121 {
122 return dev_get_drvdata(&serdev->dev);
123 }
124
125 static inline void serdev_device_set_drvdata(struct serdev_device *serdev, void *data)
126 {
127 dev_set_drvdata(&serdev->dev, data);
128 }
129
130 /**
131 * serdev_device_put() - decrement serdev device refcount
132 * @serdev serdev device.
133 */
134 static inline void serdev_device_put(struct serdev_device *serdev)
135 {
136 if (serdev)
137 put_device(&serdev->dev);
138 }
139
140 static inline void serdev_device_set_client_ops(struct serdev_device *serdev,
141 const struct serdev_device_ops *ops)
142 {
143 serdev->ops = ops;
144 }
145
146 static inline
147 void *serdev_controller_get_drvdata(const struct serdev_controller *ctrl)
148 {
149 return ctrl ? dev_get_drvdata(&ctrl->dev) : NULL;
150 }
151
152 static inline void serdev_controller_set_drvdata(struct serdev_controller *ctrl,
153 void *data)
154 {
155 dev_set_drvdata(&ctrl->dev, data);
156 }
157
158 /**
159 * serdev_controller_put() - decrement controller refcount
160 * @ctrl serdev controller.
161 */
162 static inline void serdev_controller_put(struct serdev_controller *ctrl)
163 {
164 if (ctrl)
165 put_device(&ctrl->dev);
166 }
167
168 struct serdev_device *serdev_device_alloc(struct serdev_controller *);
169 int serdev_device_add(struct serdev_device *);
170 void serdev_device_remove(struct serdev_device *);
171
172 struct serdev_controller *serdev_controller_alloc(struct device *host,
173 struct device *parent,
174 size_t size);
175 int serdev_controller_add(struct serdev_controller *);
176 void serdev_controller_remove(struct serdev_controller *);
177
178 static inline void serdev_controller_write_wakeup(struct serdev_controller *ctrl)
179 {
180 struct serdev_device *serdev = ctrl->serdev;
181
182 if (!serdev || !serdev->ops->write_wakeup)
183 return;
184
185 serdev->ops->write_wakeup(serdev);
186 }
187
188 static inline size_t serdev_controller_receive_buf(struct serdev_controller *ctrl,
189 const u8 *data,
190 size_t count)
191 {
192 struct serdev_device *serdev = ctrl->serdev;
193
194 if (!serdev || !serdev->ops->receive_buf)
195 return 0;
196
197 return serdev->ops->receive_buf(serdev, data, count);
198 }
199
200 #if IS_ENABLED(CONFIG_SERIAL_DEV_BUS)
201
202 int serdev_device_open(struct serdev_device *);
203 void serdev_device_close(struct serdev_device *);
204 int devm_serdev_device_open(struct device *, struct serdev_device *);
205 unsigned int serdev_device_set_baudrate(struct serdev_device *, unsigned int);
206 void serdev_device_set_flow_control(struct serdev_device *, bool);
207 int serdev_device_write_buf(struct serdev_device *, const u8 *, size_t);
208 void serdev_device_wait_until_sent(struct serdev_device *, long);
209 int serdev_device_get_tiocm(struct serdev_device *);
210 int serdev_device_set_tiocm(struct serdev_device *, int, int);
211 int serdev_device_break_ctl(struct serdev_device *serdev, int break_state);
212 void serdev_device_write_wakeup(struct serdev_device *);
213 ssize_t serdev_device_write(struct serdev_device *, const u8 *, size_t, long);
214 void serdev_device_write_flush(struct serdev_device *);
215 int serdev_device_write_room(struct serdev_device *);
216
217 /*
218 * serdev device driver functions
219 */
220 int __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 */
228 static 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
240 static inline int serdev_device_open(struct serdev_device *sdev)
241 {
242 return -ENODEV;
243 }
244 static inline void serdev_device_close(struct serdev_device *sdev) {}
245 static inline unsigned int serdev_device_set_baudrate(struct serdev_device *sdev, unsigned int baudrate)
246 {
247 return 0;
248 }
249 static inline void serdev_device_set_flow_control(struct serdev_device *sdev, bool enable) {}
250 static inline int serdev_device_write_buf(struct serdev_device *serdev,
251 const u8 *buf,
252 size_t count)
253 {
254 return -ENODEV;
255 }
256 static inline void serdev_device_wait_until_sent(struct serdev_device *sdev, long timeout) {}
257 static inline int serdev_device_get_tiocm(struct serdev_device *serdev)
258 {
259 return -EOPNOTSUPP;
260 }
261 static inline int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear)
262 {
263 return -EOPNOTSUPP;
264 }
265 static inline int serdev_device_break_ctl(struct serdev_device *serdev, int break_state)
266 {
267 return -EOPNOTSUPP;
268 }
269 static inline ssize_t serdev_device_write(struct serdev_device *sdev,
270 const u8 *buf, size_t count,
271 unsigned long timeout)
272 {
273 return -ENODEV;
274 }
275 static inline void serdev_device_write_flush(struct serdev_device *sdev) {}
276 static inline int serdev_device_write_room(struct serdev_device *sdev)
277 {
278 return 0;
279 }
280
281 #define serdev_device_driver_register(x)
282 #define serdev_device_driver_unregister(x)
283
284 #endif /* CONFIG_SERIAL_DEV_BUS */
285
286 static inline bool serdev_device_get_cts(struct serdev_device *serdev)
287 {
288 int status = serdev_device_get_tiocm(serdev);
289 return !!(status & TIOCM_CTS);
290 }
291
292 static inline int serdev_device_wait_for_cts(struct serdev_device *serdev, bool state, int timeout_ms)
293 {
294 bool signal;
295
296 return readx_poll_timeout(serdev_device_get_cts, serdev, signal, signal == state,
297 2000, timeout_ms * 1000);
298 }
299
300 static inline int serdev_device_set_rts(struct serdev_device *serdev, bool enable)
301 {
302 if (enable)
303 return serdev_device_set_tiocm(serdev, TIOCM_RTS, 0);
304 else
305 return serdev_device_set_tiocm(serdev, 0, TIOCM_RTS);
306 }
307
308 int serdev_device_set_parity(struct serdev_device *serdev,
309 enum serdev_parity parity);
310
311 /*
312 * serdev hooks into TTY core
313 */
314 struct tty_port;
315 struct tty_driver;
316
317 #ifdef CONFIG_SERIAL_DEV_CTRL_TTYPORT
318 struct device *serdev_tty_port_register(struct tty_port *port,
319 struct device *host,
320 struct device *parent,
321 struct tty_driver *drv, int idx);
322 int serdev_tty_port_unregister(struct tty_port *port);
323 #else
324 static inline struct device *serdev_tty_port_register(struct tty_port *port,
325 struct device *host,
326 struct device *parent,
327 struct tty_driver *drv, int idx)
328 {
329 return ERR_PTR(-ENODEV);
330 }
331 static inline int serdev_tty_port_unregister(struct tty_port *port)
332 {
333 return -ENODEV;
334 }
335 #endif /* CONFIG_SERIAL_DEV_CTRL_TTYPORT */
336
337 struct acpi_resource;
338 struct acpi_resource_uart_serialbus;
339
340 #ifdef CONFIG_ACPI
341 bool serdev_acpi_get_uart_resource(struct acpi_resource *ares,
342 struct acpi_resource_uart_serialbus **uart);
343 #else
344 static inline bool serdev_acpi_get_uart_resource(struct acpi_resource *ares,
345 struct acpi_resource_uart_serialbus **uart)
346 {
347 return false;
348 }
349 #endif /* CONFIG_ACPI */
350
351 #endif /*_LINUX_SERDEV_H */
352
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