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
15struct serdev_controller;
16struct 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 */
29struct 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 */
43struct 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
52static 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 */
64struct serdev_device_driver {
65 struct device_driver driver;
66 int (*probe)(struct serdev_device *);
67 void (*remove)(struct serdev_device *);
68};
69
70static 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
75enum serdev_parity {
76 SERDEV_PARITY_NONE,
77 SERDEV_PARITY_EVEN,
78 SERDEV_PARITY_ODD,
79};
80
81/*
82 * serdev controller structures
83 */
84struct 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 */
107struct 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
115static inline struct serdev_controller *to_serdev_controller(struct device *d)
116{
117 return container_of(d, struct serdev_controller, dev);
118}
119
120static inline void *serdev_device_get_drvdata(const struct serdev_device *serdev)
121{
122 return dev_get_drvdata(dev: &serdev->dev);
123}
124
125static inline void serdev_device_set_drvdata(struct serdev_device *serdev, void *data)
126{
127 dev_set_drvdata(dev: &serdev->dev, data);
128}
129
130/**
131 * serdev_device_put() - decrement serdev device refcount
132 * @serdev serdev device.
133 */
134static inline void serdev_device_put(struct serdev_device *serdev)
135{
136 if (serdev)
137 put_device(dev: &serdev->dev);
138}
139
140static 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
146static inline
147void *serdev_controller_get_drvdata(const struct serdev_controller *ctrl)
148{
149 return ctrl ? dev_get_drvdata(dev: &ctrl->dev) : NULL;
150}
151
152static inline void serdev_controller_set_drvdata(struct serdev_controller *ctrl,
153 void *data)
154{
155 dev_set_drvdata(dev: &ctrl->dev, data);
156}
157
158/**
159 * serdev_controller_put() - decrement controller refcount
160 * @ctrl serdev controller.
161 */
162static inline void serdev_controller_put(struct serdev_controller *ctrl)
163{
164 if (ctrl)
165 put_device(dev: &ctrl->dev);
166}
167
168struct serdev_device *serdev_device_alloc(struct serdev_controller *);
169int serdev_device_add(struct serdev_device *);
170void serdev_device_remove(struct serdev_device *);
171
172struct serdev_controller *serdev_controller_alloc(struct device *host,
173 struct device *parent,
174 size_t size);
175int serdev_controller_add(struct serdev_controller *);
176void serdev_controller_remove(struct serdev_controller *);
177
178static 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
188static 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
202int serdev_device_open(struct serdev_device *);
203void serdev_device_close(struct serdev_device *);
204int devm_serdev_device_open(struct device *, struct serdev_device *);
205unsigned int serdev_device_set_baudrate(struct serdev_device *, unsigned int);
206void serdev_device_set_flow_control(struct serdev_device *, bool);
207int serdev_device_write_buf(struct serdev_device *, const u8 *, size_t);
208void serdev_device_wait_until_sent(struct serdev_device *, long);
209int serdev_device_get_tiocm(struct serdev_device *);
210int serdev_device_set_tiocm(struct serdev_device *, int, int);
211int serdev_device_break_ctl(struct serdev_device *serdev, int break_state);
212void serdev_device_write_wakeup(struct serdev_device *);
213ssize_t serdev_device_write(struct serdev_device *, const u8 *, 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(drv: &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 u8 *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 -EOPNOTSUPP;
260}
261static inline int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear)
262{
263 return -EOPNOTSUPP;
264}
265static inline int serdev_device_break_ctl(struct serdev_device *serdev, int break_state)
266{
267 return -EOPNOTSUPP;
268}
269static 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}
275static inline void serdev_device_write_flush(struct serdev_device *sdev) {}
276static 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
286static 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
292static 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
300static 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
308int serdev_device_set_parity(struct serdev_device *serdev,
309 enum serdev_parity parity);
310
311/*
312 * serdev hooks into TTY core
313 */
314struct tty_port;
315struct tty_driver;
316
317#ifdef CONFIG_SERIAL_DEV_CTRL_TTYPORT
318struct device *serdev_tty_port_register(struct tty_port *port,
319 struct device *host,
320 struct device *parent,
321 struct tty_driver *drv, int idx);
322int serdev_tty_port_unregister(struct tty_port *port);
323#else
324static 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}
331static inline int serdev_tty_port_unregister(struct tty_port *port)
332{
333 return -ENODEV;
334}
335#endif /* CONFIG_SERIAL_DEV_CTRL_TTYPORT */
336
337struct acpi_resource;
338struct acpi_resource_uart_serialbus;
339
340#ifdef CONFIG_ACPI
341bool serdev_acpi_get_uart_resource(struct acpi_resource *ares,
342 struct acpi_resource_uart_serialbus **uart);
343#else
344static 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

source code of linux/include/linux/serdev.h