1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * Copyright 2011 Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
4  */
5 /*
6  * infrastructure for devices connected via I2C
7  */
8 
9 #ifndef __VIA_AUX_H__
10 #define __VIA_AUX_H__
11 
12 
13 #include <linux/list.h>
14 #include <linux/i2c.h>
15 #include <linux/fb.h>
16 
17 
18 struct via_aux_bus {
19 	struct i2c_adapter *adap;	/* the I2C device to access the bus */
20 	struct list_head drivers;	/* drivers for devices on this bus */
21 };
22 
23 struct via_aux_drv {
24 	struct list_head chain;		/* chain to support multiple drivers */
25 
26 	struct via_aux_bus *bus;	/* the I2C bus used */
27 	u8 addr;			/* the I2C slave address */
28 
29 	const char *name;	/* human readable name of the driver */
30 	void *data;		/* private data of this driver */
31 
32 	void (*cleanup)(struct via_aux_drv *drv);
33 	const struct fb_videomode* (*get_preferred_mode)
34 		(struct via_aux_drv *drv);
35 };
36 
37 
38 struct via_aux_bus *via_aux_probe(struct i2c_adapter *adap);
39 void via_aux_free(struct via_aux_bus *bus);
40 const struct fb_videomode *via_aux_get_preferred_mode(struct via_aux_bus *bus);
41 
42 
via_aux_add(struct via_aux_drv * drv)43 static inline bool via_aux_add(struct via_aux_drv *drv)
44 {
45 	struct via_aux_drv *data = kmalloc(sizeof(*data), GFP_KERNEL);
46 
47 	if (!data)
48 		return false;
49 
50 	*data = *drv;
51 	list_add_tail(&data->chain, &data->bus->drivers);
52 	return true;
53 }
54 
via_aux_read(struct via_aux_drv * drv,u8 start,u8 * buf,u8 len)55 static inline bool via_aux_read(struct via_aux_drv *drv, u8 start, u8 *buf,
56 	u8 len)
57 {
58 	struct i2c_msg msg[2] = {
59 		{.addr = drv->addr, .flags = 0, .len = 1, .buf = &start},
60 		{.addr = drv->addr, .flags = I2C_M_RD, .len = len, .buf = buf} };
61 
62 	return i2c_transfer(drv->bus->adap, msg, 2) == 2;
63 }
64 
65 
66 /* probe functions of existing drivers - should only be called in via_aux.c */
67 void via_aux_ch7301_probe(struct via_aux_bus *bus);
68 void via_aux_edid_probe(struct via_aux_bus *bus);
69 void via_aux_sii164_probe(struct via_aux_bus *bus);
70 void via_aux_vt1636_probe(struct via_aux_bus *bus);
71 void via_aux_vt1632_probe(struct via_aux_bus *bus);
72 void via_aux_vt1631_probe(struct via_aux_bus *bus);
73 void via_aux_vt1625_probe(struct via_aux_bus *bus);
74 void via_aux_vt1622_probe(struct via_aux_bus *bus);
75 void via_aux_vt1621_probe(struct via_aux_bus *bus);
76 
77 
78 #endif /* __VIA_AUX_H__ */
79