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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 (*open)(struct serdev_controller *);
88 void (*close)(struct serdev_controller *);
89 void (*set_flow_control)(struct serdev_controller *, bool);
90 int (*set_parity)(struct serdev_controller *, enum serdev_parity);
91 unsigned int (*set_baudrate)(struct serdev_controller *, unsigned int);
92 void (*wait_until_sent)(struct serdev_controller *, long);
93 int (*get_tiocm)(struct serdev_controller *);
94 int (*set_tiocm)(struct serdev_controller *, unsigned int, unsigned int);
95 int (*break_ctl)(struct serdev_controller *ctrl, unsigned int break_state);
96};
97
98/**
99 * struct serdev_controller - interface to the serdev controller
100 * @dev: Driver model representation of the device.
101 * @host: Serial port hardware controller device
102 * @nr: number identifier for this controller/bus.
103 * @serdev: Pointer to slave device for this controller.
104 * @ops: Controller operations.
105 */
106struct serdev_controller {
107 struct device dev;
108 struct device *host;
109 unsigned int nr;
110 struct serdev_device *serdev;
111 const struct serdev_controller_ops *ops;
112};
113
114static inline struct serdev_controller *to_serdev_controller(struct device *d)
115{
116 return container_of(d, struct serdev_controller, dev);
117}
118
119static inline void *serdev_device_get_drvdata(const struct serdev_device *serdev)
120{
121 return dev_get_drvdata(dev: &serdev->dev);
122}
123
124static inline void serdev_device_set_drvdata(struct serdev_device *serdev, void *data)
125{
126 dev_set_drvdata(dev: &serdev->dev, data);
127}
128
129/**
130 * serdev_device_put() - decrement serdev device refcount
131 * @serdev serdev device.
132 */
133static inline void serdev_device_put(struct serdev_device *serdev)
134{
135 if (serdev)
136 put_device(dev: &serdev->dev);
137}
138
139static inline void serdev_device_set_client_ops(struct serdev_device *serdev,
140 const struct serdev_device_ops *ops)
141{
142 serdev->ops = ops;
143}
144
145static inline
146void *serdev_controller_get_drvdata(const struct serdev_controller *ctrl)
147{
148 return ctrl ? dev_get_drvdata(dev: &ctrl->dev) : NULL;
149}
150
151static inline void serdev_controller_set_drvdata(struct serdev_controller *ctrl,
152 void *data)
153{
154 dev_set_drvdata(dev: &ctrl->dev, data);
155}
156
157/**
158 * serdev_controller_put() - decrement controller refcount
159 * @ctrl serdev controller.
160 */
161static inline void serdev_controller_put(struct serdev_controller *ctrl)
162{
163 if (ctrl)
164 put_device(dev: &ctrl->dev);
165}
166
167struct serdev_device *serdev_device_alloc(struct serdev_controller *);
168int serdev_device_add(struct serdev_device *);
169void serdev_device_remove(struct serdev_device *);
170
171struct serdev_controller *serdev_controller_alloc(struct device *host,
172 struct device *parent,
173 size_t size);
174int serdev_controller_add(struct serdev_controller *);
175void serdev_controller_remove(struct serdev_controller *);
176
177static inline void serdev_controller_write_wakeup(struct serdev_controller *ctrl)
178{
179 struct serdev_device *serdev = ctrl->serdev;
180
181 if (!serdev || !serdev->ops->write_wakeup)
182 return;
183
184 serdev->ops->write_wakeup(serdev);
185}
186
187static inline size_t serdev_controller_receive_buf(struct serdev_controller *ctrl,
188 const u8 *data,
189 size_t count)
190{
191 struct serdev_device *serdev = ctrl->serdev;
192
193 if (!serdev || !serdev->ops->receive_buf)
194 return 0;
195
196 return serdev->ops->receive_buf(serdev, data, count);
197}
198
199#if IS_ENABLED(CONFIG_SERIAL_DEV_BUS)
200
201int serdev_device_open(struct serdev_device *);
202void serdev_device_close(struct serdev_device *);
203int devm_serdev_device_open(struct device *, struct serdev_device *);
204unsigned int serdev_device_set_baudrate(struct serdev_device *, unsigned int);
205void serdev_device_set_flow_control(struct serdev_device *, bool);
206int serdev_device_write_buf(struct serdev_device *, const u8 *, size_t);
207void serdev_device_wait_until_sent(struct serdev_device *, long);
208int serdev_device_get_tiocm(struct serdev_device *);
209int serdev_device_set_tiocm(struct serdev_device *, int, int);
210int serdev_device_break_ctl(struct serdev_device *serdev, int break_state);
211void serdev_device_write_wakeup(struct serdev_device *);
212ssize_t serdev_device_write(struct serdev_device *, const u8 *, size_t, long);
213void serdev_device_write_flush(struct serdev_device *);
214
215/*
216 * serdev device driver functions
217 */
218int __serdev_device_driver_register(struct serdev_device_driver *, struct module *);
219#define serdev_device_driver_register(sdrv) \
220 __serdev_device_driver_register(sdrv, THIS_MODULE)
221
222/**
223 * serdev_device_driver_unregister() - unregister an serdev client driver
224 * @sdrv: the driver to unregister
225 */
226static inline void serdev_device_driver_unregister(struct serdev_device_driver *sdrv)
227{
228 if (sdrv)
229 driver_unregister(drv: &sdrv->driver);
230}
231
232#define module_serdev_device_driver(__serdev_device_driver) \
233 module_driver(__serdev_device_driver, serdev_device_driver_register, \
234 serdev_device_driver_unregister)
235
236#else
237
238static inline int serdev_device_open(struct serdev_device *sdev)
239{
240 return -ENODEV;
241}
242static inline void serdev_device_close(struct serdev_device *sdev) {}
243static inline unsigned int serdev_device_set_baudrate(struct serdev_device *sdev, unsigned int baudrate)
244{
245 return 0;
246}
247static inline void serdev_device_set_flow_control(struct serdev_device *sdev, bool enable) {}
248static inline int serdev_device_write_buf(struct serdev_device *serdev,
249 const u8 *buf,
250 size_t count)
251{
252 return -ENODEV;
253}
254static inline void serdev_device_wait_until_sent(struct serdev_device *sdev, long timeout) {}
255static inline int serdev_device_get_tiocm(struct serdev_device *serdev)
256{
257 return -EOPNOTSUPP;
258}
259static inline int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear)
260{
261 return -EOPNOTSUPP;
262}
263static inline int serdev_device_break_ctl(struct serdev_device *serdev, int break_state)
264{
265 return -EOPNOTSUPP;
266}
267static inline ssize_t serdev_device_write(struct serdev_device *sdev,
268 const u8 *buf, size_t count,
269 unsigned long timeout)
270{
271 return -ENODEV;
272}
273static inline void serdev_device_write_flush(struct serdev_device *sdev) {}
274
275#define serdev_device_driver_register(x)
276#define serdev_device_driver_unregister(x)
277
278#endif /* CONFIG_SERIAL_DEV_BUS */
279
280static inline bool serdev_device_get_cts(struct serdev_device *serdev)
281{
282 int status = serdev_device_get_tiocm(serdev);
283 return !!(status & TIOCM_CTS);
284}
285
286static inline int serdev_device_wait_for_cts(struct serdev_device *serdev, bool state, int timeout_ms)
287{
288 bool signal;
289
290 return readx_poll_timeout(serdev_device_get_cts, serdev, signal, signal == state,
291 2000, timeout_ms * 1000);
292}
293
294static inline int serdev_device_set_rts(struct serdev_device *serdev, bool enable)
295{
296 if (enable)
297 return serdev_device_set_tiocm(serdev, TIOCM_RTS, 0);
298 else
299 return serdev_device_set_tiocm(serdev, 0, TIOCM_RTS);
300}
301
302int serdev_device_set_parity(struct serdev_device *serdev,
303 enum serdev_parity parity);
304
305/*
306 * serdev hooks into TTY core
307 */
308struct tty_port;
309struct tty_driver;
310
311#ifdef CONFIG_SERIAL_DEV_CTRL_TTYPORT
312struct device *serdev_tty_port_register(struct tty_port *port,
313 struct device *host,
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 *host,
320 struct device *parent,
321 struct tty_driver *drv, int idx)
322{
323 return ERR_PTR(-ENODEV);
324}
325static inline int serdev_tty_port_unregister(struct tty_port *port)
326{
327 return -ENODEV;
328}
329#endif /* CONFIG_SERIAL_DEV_CTRL_TTYPORT */
330
331struct acpi_resource;
332struct acpi_resource_uart_serialbus;
333
334#ifdef CONFIG_ACPI
335bool serdev_acpi_get_uart_resource(struct acpi_resource *ares,
336 struct acpi_resource_uart_serialbus **uart);
337#else
338static inline bool serdev_acpi_get_uart_resource(struct acpi_resource *ares,
339 struct acpi_resource_uart_serialbus **uart)
340{
341 return false;
342}
343#endif /* CONFIG_ACPI */
344
345#endif /*_LINUX_SERDEV_H */
346

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