xref: /linux-6.15/include/linux/serdev.h (revision 5659dab2)
1 /*
2  * Copyright (C) 2016-2017 Linaro Ltd., Rob Herring <[email protected]>
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 and
6  * only version 2 as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  */
13 #ifndef _LINUX_SERDEV_H
14 #define _LINUX_SERDEV_H
15 
16 #include <linux/types.h>
17 #include <linux/device.h>
18 #include <linux/termios.h>
19 
20 struct serdev_controller;
21 struct serdev_device;
22 
23 /*
24  * serdev device structures
25  */
26 
27 /**
28  * struct serdev_device_ops - Callback operations for a serdev device
29  * @receive_buf:	Function called with data received from device.
30  * @write_wakeup:	Function called when ready to transmit more data.
31  */
32 struct serdev_device_ops {
33 	int (*receive_buf)(struct serdev_device *, const unsigned char *, size_t);
34 	void (*write_wakeup)(struct serdev_device *);
35 };
36 
37 /**
38  * struct serdev_device - Basic representation of an serdev device
39  * @dev:	Driver model representation of the device.
40  * @nr:		Device number on serdev bus.
41  * @ctrl:	serdev controller managing this device.
42  * @ops:	Device operations.
43  */
44 struct serdev_device {
45 	struct device dev;
46 	int nr;
47 	struct serdev_controller *ctrl;
48 	const struct serdev_device_ops *ops;
49 };
50 
51 static inline struct serdev_device *to_serdev_device(struct device *d)
52 {
53 	return container_of(d, struct serdev_device, dev);
54 }
55 
56 /**
57  * struct serdev_device_driver - serdev slave device driver
58  * @driver:	serdev device drivers should initialize name field of this
59  *		structure.
60  * @probe:	binds this driver to a serdev device.
61  * @remove:	unbinds this driver from the serdev device.
62  */
63 struct serdev_device_driver {
64 	struct device_driver driver;
65 	int	(*probe)(struct serdev_device *);
66 	void	(*remove)(struct serdev_device *);
67 };
68 
69 static inline struct serdev_device_driver *to_serdev_device_driver(struct device_driver *d)
70 {
71 	return container_of(d, struct serdev_device_driver, driver);
72 }
73 
74 /*
75  * serdev controller structures
76  */
77 struct serdev_controller_ops {
78 	int (*write_buf)(struct serdev_controller *, const unsigned char *, size_t);
79 	void (*write_flush)(struct serdev_controller *);
80 	int (*write_room)(struct serdev_controller *);
81 	int (*open)(struct serdev_controller *);
82 	void (*close)(struct serdev_controller *);
83 	void (*set_flow_control)(struct serdev_controller *, bool);
84 	unsigned int (*set_baudrate)(struct serdev_controller *, unsigned int);
85 	void (*wait_until_sent)(struct serdev_controller *, long);
86 	int (*get_tiocm)(struct serdev_controller *);
87 	int (*set_tiocm)(struct serdev_controller *, unsigned int, unsigned int);
88 };
89 
90 /**
91  * struct serdev_controller - interface to the serdev controller
92  * @dev:	Driver model representation of the device.
93  * @nr:		number identifier for this controller/bus.
94  * @serdev:	Pointer to slave device for this controller.
95  * @ops:	Controller operations.
96  */
97 struct serdev_controller {
98 	struct device		dev;
99 	unsigned int		nr;
100 	struct serdev_device	*serdev;
101 	const struct serdev_controller_ops *ops;
102 };
103 
104 static inline struct serdev_controller *to_serdev_controller(struct device *d)
105 {
106 	return container_of(d, struct serdev_controller, dev);
107 }
108 
109 static inline void *serdev_device_get_drvdata(const struct serdev_device *serdev)
110 {
111 	return dev_get_drvdata(&serdev->dev);
112 }
113 
114 static inline void serdev_device_set_drvdata(struct serdev_device *serdev, void *data)
115 {
116 	dev_set_drvdata(&serdev->dev, data);
117 }
118 
119 /**
120  * serdev_device_put() - decrement serdev device refcount
121  * @serdev	serdev device.
122  */
123 static inline void serdev_device_put(struct serdev_device *serdev)
124 {
125 	if (serdev)
126 		put_device(&serdev->dev);
127 }
128 
129 static inline void serdev_device_set_client_ops(struct serdev_device *serdev,
130 					      const struct serdev_device_ops *ops)
131 {
132 	serdev->ops = ops;
133 }
134 
135 static inline
136 void *serdev_controller_get_drvdata(const struct serdev_controller *ctrl)
137 {
138 	return ctrl ? dev_get_drvdata(&ctrl->dev) : NULL;
139 }
140 
141 static inline void serdev_controller_set_drvdata(struct serdev_controller *ctrl,
142 					       void *data)
143 {
144 	dev_set_drvdata(&ctrl->dev, data);
145 }
146 
147 /**
148  * serdev_controller_put() - decrement controller refcount
149  * @ctrl	serdev controller.
150  */
151 static inline void serdev_controller_put(struct serdev_controller *ctrl)
152 {
153 	if (ctrl)
154 		put_device(&ctrl->dev);
155 }
156 
157 struct serdev_device *serdev_device_alloc(struct serdev_controller *);
158 int serdev_device_add(struct serdev_device *);
159 void serdev_device_remove(struct serdev_device *);
160 
161 struct serdev_controller *serdev_controller_alloc(struct device *, size_t);
162 int serdev_controller_add(struct serdev_controller *);
163 void serdev_controller_remove(struct serdev_controller *);
164 
165 static inline void serdev_controller_write_wakeup(struct serdev_controller *ctrl)
166 {
167 	struct serdev_device *serdev = ctrl->serdev;
168 
169 	if (!serdev || !serdev->ops->write_wakeup)
170 		return;
171 
172 	serdev->ops->write_wakeup(ctrl->serdev);
173 }
174 
175 static inline int serdev_controller_receive_buf(struct serdev_controller *ctrl,
176 					      const unsigned char *data,
177 					      size_t count)
178 {
179 	struct serdev_device *serdev = ctrl->serdev;
180 
181 	if (!serdev || !serdev->ops->receive_buf)
182 		return -EINVAL;
183 
184 	return serdev->ops->receive_buf(ctrl->serdev, data, count);
185 }
186 
187 #if IS_ENABLED(CONFIG_SERIAL_DEV_BUS)
188 
189 int serdev_device_open(struct serdev_device *);
190 void serdev_device_close(struct serdev_device *);
191 unsigned int serdev_device_set_baudrate(struct serdev_device *, unsigned int);
192 void serdev_device_set_flow_control(struct serdev_device *, bool);
193 void serdev_device_wait_until_sent(struct serdev_device *, long);
194 int serdev_device_get_tiocm(struct serdev_device *);
195 int serdev_device_set_tiocm(struct serdev_device *, int, int);
196 int serdev_device_write_buf(struct serdev_device *, const unsigned char *, size_t);
197 void serdev_device_write_flush(struct serdev_device *);
198 int serdev_device_write_room(struct serdev_device *);
199 
200 /*
201  * serdev device driver functions
202  */
203 int __serdev_device_driver_register(struct serdev_device_driver *, struct module *);
204 #define serdev_device_driver_register(sdrv) \
205 	__serdev_device_driver_register(sdrv, THIS_MODULE)
206 
207 /**
208  * serdev_device_driver_unregister() - unregister an serdev client driver
209  * @sdrv:	the driver to unregister
210  */
211 static inline void serdev_device_driver_unregister(struct serdev_device_driver *sdrv)
212 {
213 	if (sdrv)
214 		driver_unregister(&sdrv->driver);
215 }
216 
217 #define module_serdev_device_driver(__serdev_device_driver) \
218 	module_driver(__serdev_device_driver, serdev_device_driver_register, \
219 			serdev_device_driver_unregister)
220 
221 #else
222 
223 static inline int serdev_device_open(struct serdev_device *sdev)
224 {
225 	return -ENODEV;
226 }
227 static inline void serdev_device_close(struct serdev_device *sdev) {}
228 static inline unsigned int serdev_device_set_baudrate(struct serdev_device *sdev, unsigned int baudrate)
229 {
230 	return 0;
231 }
232 static inline void serdev_device_set_flow_control(struct serdev_device *sdev, bool enable) {}
233 static inline void serdev_device_wait_until_sent(struct serdev_device *sdev, long timeout) {}
234 static inline int serdev_device_get_tiocm(struct serdev_device *serdev)
235 {
236 	return -ENOTSUPP;
237 }
238 static inline int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear)
239 {
240 	return -ENOTSUPP;
241 }
242 static inline int serdev_device_write_buf(struct serdev_device *sdev, const unsigned char *buf, size_t count)
243 {
244 	return -ENODEV;
245 }
246 static inline void serdev_device_write_flush(struct serdev_device *sdev) {}
247 static inline int serdev_device_write_room(struct serdev_device *sdev)
248 {
249 	return 0;
250 }
251 
252 #define serdev_device_driver_register(x)
253 #define serdev_device_driver_unregister(x)
254 
255 #endif /* CONFIG_SERIAL_DEV_BUS */
256 
257 /*
258  * serdev hooks into TTY core
259  */
260 struct tty_port;
261 struct tty_driver;
262 
263 #ifdef CONFIG_SERIAL_DEV_CTRL_TTYPORT
264 struct device *serdev_tty_port_register(struct tty_port *port,
265 					struct device *parent,
266 					struct tty_driver *drv, int idx);
267 void serdev_tty_port_unregister(struct tty_port *port);
268 #else
269 static inline struct device *serdev_tty_port_register(struct tty_port *port,
270 					   struct device *parent,
271 					   struct tty_driver *drv, int idx)
272 {
273 	return ERR_PTR(-ENODEV);
274 }
275 static inline void serdev_tty_port_unregister(struct tty_port *port) {}
276 #endif /* CONFIG_SERIAL_DEV_CTRL_TTYPORT */
277 
278 #endif /*_LINUX_SERDEV_H */
279