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 
10 #ifndef __DDBRIDGE_I2C_H__
11 #define __DDBRIDGE_I2C_H__
12 
13 #include <linux/i2c.h>
14 
15 #include "ddbridge.h"
16 
17 /******************************************************************************/
18 
19 void ddb_i2c_release(struct ddb *dev);
20 int ddb_i2c_init(struct ddb *dev);
21 
22 /******************************************************************************/
23 
24 static int __maybe_unused i2c_io(struct i2c_adapter *adapter, u8 adr,
25 				 u8 *wbuf, u32 wlen, u8 *rbuf, u32 rlen)
26 {
27 	struct i2c_msg msgs[2] = { { .addr = adr,  .flags = 0,
28 				     .buf  = wbuf, .len   = wlen },
29 				   { .addr = adr,  .flags = I2C_M_RD,
30 				     .buf  = rbuf, .len   = rlen } };
31 
32 	return (i2c_transfer(adapter, msgs, 2) == 2) ? 0 : -1;
33 }
34 
35 static int __maybe_unused i2c_write(struct i2c_adapter *adap, u8 adr,
36 				    u8 *data, int len)
37 {
38 	struct i2c_msg msg = { .addr = adr, .flags = 0,
39 			       .buf = data, .len = len };
40 
41 	return (i2c_transfer(adap, &msg, 1) == 1) ? 0 : -1;
42 }
43 
44 static int __maybe_unused i2c_read(struct i2c_adapter *adapter, u8 adr, u8 *val)
45 {
46 	struct i2c_msg msgs[1] = { { .addr = adr, .flags = I2C_M_RD,
47 				     .buf  = val, .len   = 1 } };
48 
49 	return (i2c_transfer(adapter, msgs, 1) == 1) ? 0 : -1;
50 }
51 
52 static int __maybe_unused i2c_read_regs(struct i2c_adapter *adapter,
53 					u8 adr, u8 reg, u8 *val, u8 len)
54 {
55 	struct i2c_msg msgs[2] = { { .addr = adr,  .flags = 0,
56 				     .buf  = &reg, .len   = 1 },
57 				   { .addr = adr,  .flags = I2C_M_RD,
58 				     .buf  = val,  .len   = len } };
59 
60 	return (i2c_transfer(adapter, msgs, 2) == 2) ? 0 : -1;
61 }
62 
63 static int __maybe_unused i2c_read_regs16(struct i2c_adapter *adapter,
64 					  u8 adr, u16 reg, u8 *val, u8 len)
65 {
66 	u8 msg[2] = { reg >> 8, reg & 0xff };
67 	struct i2c_msg msgs[2] = { { .addr = adr, .flags = 0,
68 				     .buf  = msg, .len   = 2 },
69 				   { .addr = adr, .flags = I2C_M_RD,
70 				     .buf  = val, .len   = len } };
71 
72 	return (i2c_transfer(adapter, msgs, 2) == 2) ? 0 : -1;
73 }
74 
75 static int __maybe_unused i2c_write_reg16(struct i2c_adapter *adap,
76 					  u8 adr, u16 reg, u8 val)
77 {
78 	u8 msg[3] = { reg >> 8, reg & 0xff, val };
79 
80 	return i2c_write(adap, adr, msg, 3);
81 }
82 
83 static int __maybe_unused i2c_write_reg(struct i2c_adapter *adap,
84 					u8 adr, u8 reg, u8 val)
85 {
86 	u8 msg[2] = { reg, val };
87 
88 	return i2c_write(adap, adr, msg, 2);
89 }
90 
91 static int __maybe_unused i2c_read_reg16(struct i2c_adapter *adapter,
92 					 u8 adr, u16 reg, u8 *val)
93 {
94 	return i2c_read_regs16(adapter, adr, reg, val, 1);
95 }
96 
97 static int __maybe_unused i2c_read_reg(struct i2c_adapter *adapter,
98 				       u8 adr, u8 reg, u8 *val)
99 {
100 	return i2c_read_regs(adapter, adr, reg, val, 1);
101 }
102 
103 #endif /* __DDBRIDGE_I2C_H__ */
104