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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};
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 */
105struct serdev_controller {
106 struct device dev;
107 unsigned int nr;
108 struct serdev_device *serdev;
109 const struct serdev_controller_ops *ops;
110};
111
112static inline struct serdev_controller *to_serdev_controller(struct device *d)
113{
114 return container_of(d, struct serdev_controller, dev);
115}
116
117static inline void *serdev_device_get_drvdata(const struct serdev_device *serdev)
118{
119 return dev_get_drvdata(&serdev->dev);
120}
121
122static 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 */
131static inline void serdev_device_put(struct serdev_device *serdev)
132{
133 if (serdev)
134 put_device(&serdev->dev);
135}
136
137static 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
143static inline
144void *serdev_controller_get_drvdata(const struct serdev_controller *ctrl)
145{
146 return ctrl ? dev_get_drvdata(&ctrl->dev) : NULL;
147}
148
149static 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 */
159static inline void serdev_controller_put(struct serdev_controller *ctrl)
160{
161 if (ctrl)
162 put_device(&ctrl->dev);
163}
164
165struct serdev_device *serdev_device_alloc(struct serdev_controller *);
166int serdev_device_add(struct serdev_device *);
167void serdev_device_remove(struct serdev_device *);
168
169struct serdev_controller *serdev_controller_alloc(struct device *, size_t);
170int serdev_controller_add(struct serdev_controller *);
171void serdev_controller_remove(struct serdev_controller *);
172
173static 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
183static 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
197int serdev_device_open(struct serdev_device *);
198void serdev_device_close(struct serdev_device *);
199int devm_serdev_device_open(struct device *, struct serdev_device *);
200unsigned int serdev_device_set_baudrate(struct serdev_device *, unsigned int);
201void serdev_device_set_flow_control(struct serdev_device *, bool);
202int serdev_device_write_buf(struct serdev_device *, const unsigned char *, size_t);
203void serdev_device_wait_until_sent(struct serdev_device *, long);
204int serdev_device_get_tiocm(struct serdev_device *);
205int serdev_device_set_tiocm(struct serdev_device *, int, int);
206void serdev_device_write_wakeup(struct serdev_device *);
207int serdev_device_write(struct serdev_device *, const unsigned char *, size_t, long);
208void serdev_device_write_flush(struct serdev_device *);
209int serdev_device_write_room(struct serdev_device *);
210
211/*
212 * serdev device driver functions
213 */
214int __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 */
222static 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
234static inline int serdev_device_open(struct serdev_device *sdev)
235{
236 return -ENODEV;
237}
238static inline void serdev_device_close(struct serdev_device *sdev) {}
239static inline unsigned int serdev_device_set_baudrate(struct serdev_device *sdev, unsigned int baudrate)
240{
241 return 0;
242}
243static inline void serdev_device_set_flow_control(struct serdev_device *sdev, bool enable) {}
244static inline int serdev_device_write_buf(struct serdev_device *serdev,
245 const unsigned char *buf,
246 size_t count)
247{
248 return -ENODEV;
249}
250static inline void serdev_device_wait_until_sent(struct serdev_device *sdev, long timeout) {}
251static inline int serdev_device_get_tiocm(struct serdev_device *serdev)
252{
253 return -ENOTSUPP;
254}
255static inline int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear)
256{
257 return -ENOTSUPP;
258}
259static 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}
264static inline void serdev_device_write_flush(struct serdev_device *sdev) {}
265static 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
275static 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
281static 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
289static 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
297int serdev_device_set_parity(struct serdev_device *serdev,
298 enum serdev_parity parity);
299
300/*
301 * serdev hooks into TTY core
302 */
303struct tty_port;
304struct tty_driver;
305
306#ifdef CONFIG_SERIAL_DEV_CTRL_TTYPORT
307struct device *serdev_tty_port_register(struct tty_port *port,
308 struct device *parent,
309 struct tty_driver *drv, int idx);
310int serdev_tty_port_unregister(struct tty_port *port);
311#else
312static inline struct device *serdev_tty_port_register(struct tty_port *port,
313 struct device *parent,
314 struct tty_driver *drv, int idx)
315{
316 return ERR_PTR(-ENODEV);
317}
318static inline int serdev_tty_port_unregister(struct tty_port *port)
319{
320 return -ENODEV;
321}
322#endif /* CONFIG_SERIAL_DEV_CTRL_TTYPORT */
323
324struct acpi_resource;
325struct acpi_resource_uart_serialbus;
326
327#ifdef CONFIG_ACPI
328bool serdev_acpi_get_uart_resource(struct acpi_resource *ares,
329 struct acpi_resource_uart_serialbus **uart);
330#else
331static 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 */