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(&serdev->dev);
123}
124
125static 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 */
134static inline void serdev_device_put(struct serdev_device *serdev)
135{
136	if (serdev)
137		put_device(&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(&ctrl->dev) : NULL;
150}
151
152static 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 */
162static inline void serdev_controller_put(struct serdev_controller *ctrl)
163{
164	if (ctrl)
165		put_device(&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(&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