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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 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 */
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 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 */
106struct serdev_controller {
107 struct device dev;
108 unsigned int nr;
109 struct serdev_device *serdev;
110 const struct serdev_controller_ops *ops;
111};
112
113static inline struct serdev_controller *to_serdev_controller(struct device *d)
114{
115 return container_of(d, struct serdev_controller, dev);
116}
117
118static inline void *serdev_device_get_drvdata(const struct serdev_device *serdev)
119{
120 return dev_get_drvdata(&serdev->dev);
121}
122
123static 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 */
132static inline void serdev_device_put(struct serdev_device *serdev)
133{
134 if (serdev)
135 put_device(&serdev->dev);
136}
137
138static 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
144static inline
145void *serdev_controller_get_drvdata(const struct serdev_controller *ctrl)
146{
147 return ctrl ? dev_get_drvdata(&ctrl->dev) : NULL;
148}
149
150static 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 */
160static inline void serdev_controller_put(struct serdev_controller *ctrl)
161{
162 if (ctrl)
163 put_device(&ctrl->dev);
164}
165
166struct serdev_device *serdev_device_alloc(struct serdev_controller *);
167int serdev_device_add(struct serdev_device *);
168void serdev_device_remove(struct serdev_device *);
169
170struct serdev_controller *serdev_controller_alloc(struct device *, size_t);
171int serdev_controller_add(struct serdev_controller *);
172void serdev_controller_remove(struct serdev_controller *);
173
174static 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
184static 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
198int serdev_device_open(struct serdev_device *);
199void serdev_device_close(struct serdev_device *);
200int devm_serdev_device_open(struct device *, struct serdev_device *);
201unsigned int serdev_device_set_baudrate(struct serdev_device *, unsigned int);
202void serdev_device_set_flow_control(struct serdev_device *, bool);
203int serdev_device_write_buf(struct serdev_device *, const unsigned char *, size_t);
204void serdev_device_wait_until_sent(struct serdev_device *, long);
205int serdev_device_get_tiocm(struct serdev_device *);
206int serdev_device_set_tiocm(struct serdev_device *, int, int);
207int serdev_device_break_ctl(struct serdev_device *serdev, int break_state);
208void serdev_device_write_wakeup(struct serdev_device *);
209int serdev_device_write(struct serdev_device *, const unsigned char *, size_t, long);
210void serdev_device_write_flush(struct serdev_device *);
211int serdev_device_write_room(struct serdev_device *);
212
213/*
214 * serdev device driver functions
215 */
216int __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 */
224static 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
236static inline int serdev_device_open(struct serdev_device *sdev)
237{
238 return -ENODEV;
239}
240static inline void serdev_device_close(struct serdev_device *sdev) {}
241static inline unsigned int serdev_device_set_baudrate(struct serdev_device *sdev, unsigned int baudrate)
242{
243 return 0;
244}
245static inline void serdev_device_set_flow_control(struct serdev_device *sdev, bool enable) {}
246static inline int serdev_device_write_buf(struct serdev_device *serdev,
247 const unsigned char *buf,
248 size_t count)
249{
250 return -ENODEV;
251}
252static inline void serdev_device_wait_until_sent(struct serdev_device *sdev, long timeout) {}
253static inline int serdev_device_get_tiocm(struct serdev_device *serdev)
254{
255 return -EOPNOTSUPP;
256}
257static inline int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear)
258{
259 return -EOPNOTSUPP;
260}
261static inline int serdev_device_break_ctl(struct serdev_device *serdev, int break_state)
262{
263 return -EOPNOTSUPP;
264}
265static 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}
270static inline void serdev_device_write_flush(struct serdev_device *sdev) {}
271static 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
281static 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
287static 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
295static 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
303int serdev_device_set_parity(struct serdev_device *serdev,
304 enum serdev_parity parity);
305
306/*
307 * serdev hooks into TTY core
308 */
309struct tty_port;
310struct tty_driver;
311
312#ifdef CONFIG_SERIAL_DEV_CTRL_TTYPORT
313struct device *serdev_tty_port_register(struct tty_port *port,
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 *parent,
320 struct tty_driver *drv, int idx)
321{
322 return ERR_PTR(-ENODEV);
323}
324static inline int serdev_tty_port_unregister(struct tty_port *port)
325{
326 return -ENODEV;
327}
328#endif /* CONFIG_SERIAL_DEV_CTRL_TTYPORT */
329
330struct acpi_resource;
331struct acpi_resource_uart_serialbus;
332
333#ifdef CONFIG_ACPI
334bool serdev_acpi_get_uart_resource(struct acpi_resource *ares,
335 struct acpi_resource_uart_serialbus **uart);
336#else
337static 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 */