1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * ddbridge-i2c.h: Digital Devices bridge i2c driver
4 *
5 * Copyright (C) 2010-2017 Digital Devices GmbH
6 *                         Ralph Metzler <rjkm@metzlerbros.de>
7 *                         Marcus Metzler <mocm@metzlerbros.de>
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * version 2 only, as published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 * GNU General Public License for more details.
17 */
18
19#ifndef __DDBRIDGE_I2C_H__
20#define __DDBRIDGE_I2C_H__
21
22#include <linux/i2c.h>
23
24#include "ddbridge.h"
25
26/******************************************************************************/
27
28void ddb_i2c_release(struct ddb *dev);
29int ddb_i2c_init(struct ddb *dev);
30
31/******************************************************************************/
32
33static int __maybe_unused i2c_io(struct i2c_adapter *adapter, u8 adr,
34				 u8 *wbuf, u32 wlen, u8 *rbuf, u32 rlen)
35{
36	struct i2c_msg msgs[2] = { { .addr = adr,  .flags = 0,
37				     .buf  = wbuf, .len   = wlen },
38				   { .addr = adr,  .flags = I2C_M_RD,
39				     .buf  = rbuf, .len   = rlen } };
40
41	return (i2c_transfer(adapter, msgs, 2) == 2) ? 0 : -1;
42}
43
44static int __maybe_unused i2c_write(struct i2c_adapter *adap, u8 adr,
45				    u8 *data, int len)
46{
47	struct i2c_msg msg = { .addr = adr, .flags = 0,
48			       .buf = data, .len = len };
49
50	return (i2c_transfer(adap, &msg, 1) == 1) ? 0 : -1;
51}
52
53static int __maybe_unused i2c_read(struct i2c_adapter *adapter, u8 adr, u8 *val)
54{
55	struct i2c_msg msgs[1] = { { .addr = adr, .flags = I2C_M_RD,
56				     .buf  = val, .len   = 1 } };
57
58	return (i2c_transfer(adapter, msgs, 1) == 1) ? 0 : -1;
59}
60
61static int __maybe_unused i2c_read_regs(struct i2c_adapter *adapter,
62					u8 adr, u8 reg, u8 *val, u8 len)
63{
64	struct i2c_msg msgs[2] = { { .addr = adr,  .flags = 0,
65				     .buf  = &reg, .len   = 1 },
66				   { .addr = adr,  .flags = I2C_M_RD,
67				     .buf  = val,  .len   = len } };
68
69	return (i2c_transfer(adapter, msgs, 2) == 2) ? 0 : -1;
70}
71
72static int __maybe_unused i2c_read_regs16(struct i2c_adapter *adapter,
73					  u8 adr, u16 reg, u8 *val, u8 len)
74{
75	u8 msg[2] = { reg >> 8, reg & 0xff };
76	struct i2c_msg msgs[2] = { { .addr = adr, .flags = 0,
77				     .buf  = msg, .len   = 2 },
78				   { .addr = adr, .flags = I2C_M_RD,
79				     .buf  = val, .len   = len } };
80
81	return (i2c_transfer(adapter, msgs, 2) == 2) ? 0 : -1;
82}
83
84static int __maybe_unused i2c_write_reg16(struct i2c_adapter *adap,
85					  u8 adr, u16 reg, u8 val)
86{
87	u8 msg[3] = { reg >> 8, reg & 0xff, val };
88
89	return i2c_write(adap, adr, msg, 3);
90}
91
92static int __maybe_unused i2c_write_reg(struct i2c_adapter *adap,
93					u8 adr, u8 reg, u8 val)
94{
95	u8 msg[2] = { reg, val };
96
97	return i2c_write(adap, adr, msg, 2);
98}
99
100static int __maybe_unused i2c_read_reg16(struct i2c_adapter *adapter,
101					 u8 adr, u16 reg, u8 *val)
102{
103	return i2c_read_regs16(adapter, adr, reg, val, 1);
104}
105
106static int __maybe_unused i2c_read_reg(struct i2c_adapter *adapter,
107				       u8 adr, u8 reg, u8 *val)
108{
109	return i2c_read_regs(adapter, adr, reg, val, 1);
110}
111
112#endif /* __DDBRIDGE_I2C_H__ */
113