xref: /openbmc/linux/drivers/mfd/88pm860x-i2c.c (revision f3539c12)
1 /*
2  * I2C driver for Marvell 88PM860x
3  *
4  * Copyright (C) 2009 Marvell International Ltd.
5  *
6  * Author: Haojian Zhuang <haojian.zhuang@marvell.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  */
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/i2c.h>
15 #include <linux/regmap.h>
16 #include <linux/mfd/88pm860x.h>
17 
18 int pm860x_reg_read(struct i2c_client *i2c, int reg)
19 {
20 	struct pm860x_chip *chip = i2c_get_clientdata(i2c);
21 	struct regmap *map = (i2c == chip->client) ? chip->regmap
22 				: chip->regmap_companion;
23 	unsigned int data;
24 	int ret;
25 
26 	ret = regmap_read(map, reg, &data);
27 	if (ret < 0)
28 		return ret;
29 	else
30 		return (int)data;
31 }
32 EXPORT_SYMBOL(pm860x_reg_read);
33 
34 int pm860x_reg_write(struct i2c_client *i2c, int reg,
35 		     unsigned char data)
36 {
37 	struct pm860x_chip *chip = i2c_get_clientdata(i2c);
38 	struct regmap *map = (i2c == chip->client) ? chip->regmap
39 				: chip->regmap_companion;
40 	int ret;
41 
42 	ret = regmap_write(map, reg, data);
43 	return ret;
44 }
45 EXPORT_SYMBOL(pm860x_reg_write);
46 
47 int pm860x_bulk_read(struct i2c_client *i2c, int reg,
48 		     int count, unsigned char *buf)
49 {
50 	struct pm860x_chip *chip = i2c_get_clientdata(i2c);
51 	struct regmap *map = (i2c == chip->client) ? chip->regmap
52 				: chip->regmap_companion;
53 	int ret;
54 
55 	ret = regmap_raw_read(map, reg, buf, count);
56 	return ret;
57 }
58 EXPORT_SYMBOL(pm860x_bulk_read);
59 
60 int pm860x_bulk_write(struct i2c_client *i2c, int reg,
61 		      int count, unsigned char *buf)
62 {
63 	struct pm860x_chip *chip = i2c_get_clientdata(i2c);
64 	struct regmap *map = (i2c == chip->client) ? chip->regmap
65 				: chip->regmap_companion;
66 	int ret;
67 
68 	ret = regmap_raw_write(map, reg, buf, count);
69 	return ret;
70 }
71 EXPORT_SYMBOL(pm860x_bulk_write);
72 
73 int pm860x_set_bits(struct i2c_client *i2c, int reg,
74 		    unsigned char mask, unsigned char data)
75 {
76 	struct pm860x_chip *chip = i2c_get_clientdata(i2c);
77 	struct regmap *map = (i2c == chip->client) ? chip->regmap
78 				: chip->regmap_companion;
79 	int ret;
80 
81 	ret = regmap_update_bits(map, reg, mask, data);
82 	return ret;
83 }
84 EXPORT_SYMBOL(pm860x_set_bits);
85 
86 static int read_device(struct i2c_client *i2c, int reg,
87 		       int bytes, void *dest)
88 {
89 	unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX + 3];
90 	unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX + 2];
91 	struct i2c_adapter *adap = i2c->adapter;
92 	struct i2c_msg msg[2] = {
93 					{
94 						.addr = i2c->addr,
95 						.flags = 0,
96 						.len = 1,
97 						.buf = msgbuf0
98 					},
99 					{	.addr = i2c->addr,
100 						.flags = I2C_M_RD,
101 						.len = 0,
102 						.buf = msgbuf1
103 					},
104 				};
105 	int num = 1, ret = 0;
106 
107 	if (dest == NULL)
108 		return -EINVAL;
109 	msgbuf0[0] = (unsigned char)reg;	/* command */
110 	msg[1].len = bytes;
111 
112 	/* if data needs to read back, num should be 2 */
113 	if (bytes > 0)
114 		num = 2;
115 	ret = adap->algo->master_xfer(adap, msg, num);
116 	memcpy(dest, msgbuf1, bytes);
117 	if (ret < 0)
118 		return ret;
119 	return 0;
120 }
121 
122 static int write_device(struct i2c_client *i2c, int reg,
123 			int bytes, void *src)
124 {
125 	unsigned char buf[2];
126 	struct i2c_adapter *adap = i2c->adapter;
127 	struct i2c_msg msg;
128 	int ret;
129 
130 	buf[0] = (unsigned char)reg;
131 	memcpy(&buf[1], src, bytes);
132 	msg.addr = i2c->addr;
133 	msg.flags = 0;
134 	msg.len = bytes + 1;
135 	msg.buf = buf;
136 
137 	ret = adap->algo->master_xfer(adap, &msg, 1);
138 	if (ret < 0)
139 		return ret;
140 	return 0;
141 }
142 
143 int pm860x_page_reg_write(struct i2c_client *i2c, int reg,
144 			  unsigned char data)
145 {
146 	unsigned char zero;
147 	int ret;
148 
149 	i2c_lock_adapter(i2c->adapter);
150 	read_device(i2c, 0xFA, 0, &zero);
151 	read_device(i2c, 0xFB, 0, &zero);
152 	read_device(i2c, 0xFF, 0, &zero);
153 	ret = write_device(i2c, reg, 1, &data);
154 	read_device(i2c, 0xFE, 0, &zero);
155 	read_device(i2c, 0xFC, 0, &zero);
156 	i2c_unlock_adapter(i2c->adapter);
157 	return ret;
158 }
159 EXPORT_SYMBOL(pm860x_page_reg_write);
160 
161 int pm860x_page_bulk_read(struct i2c_client *i2c, int reg,
162 			  int count, unsigned char *buf)
163 {
164 	unsigned char zero = 0;
165 	int ret;
166 
167 	i2c_lock_adapter(i2c->adapter);
168 	read_device(i2c, 0xfa, 0, &zero);
169 	read_device(i2c, 0xfb, 0, &zero);
170 	read_device(i2c, 0xff, 0, &zero);
171 	ret = read_device(i2c, reg, count, buf);
172 	read_device(i2c, 0xFE, 0, &zero);
173 	read_device(i2c, 0xFC, 0, &zero);
174 	i2c_unlock_adapter(i2c->adapter);
175 	return ret;
176 }
177 EXPORT_SYMBOL(pm860x_page_bulk_read);
178