xref: /openbmc/linux/drivers/mfd/88pm860x-i2c.c (revision fb574682)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * I2C driver for Marvell 88PM860x
4  *
5  * Copyright (C) 2009 Marvell International Ltd.
6  *
7  * Author: Haojian Zhuang <haojian.zhuang@marvell.com>
8  */
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/i2c.h>
12 #include <linux/regmap.h>
13 #include <linux/mfd/88pm860x.h>
14 
15 int pm860x_reg_read(struct i2c_client *i2c, int reg)
16 {
17 	struct pm860x_chip *chip = i2c_get_clientdata(i2c);
18 	struct regmap *map = (i2c == chip->client) ? chip->regmap
19 				: chip->regmap_companion;
20 	unsigned int data;
21 	int ret;
22 
23 	ret = regmap_read(map, reg, &data);
24 	if (ret < 0)
25 		return ret;
26 	else
27 		return (int)data;
28 }
29 EXPORT_SYMBOL(pm860x_reg_read);
30 
31 int pm860x_reg_write(struct i2c_client *i2c, int reg,
32 		     unsigned char data)
33 {
34 	struct pm860x_chip *chip = i2c_get_clientdata(i2c);
35 	struct regmap *map = (i2c == chip->client) ? chip->regmap
36 				: chip->regmap_companion;
37 	int ret;
38 
39 	ret = regmap_write(map, reg, data);
40 	return ret;
41 }
42 EXPORT_SYMBOL(pm860x_reg_write);
43 
44 int pm860x_bulk_read(struct i2c_client *i2c, int reg,
45 		     int count, unsigned char *buf)
46 {
47 	struct pm860x_chip *chip = i2c_get_clientdata(i2c);
48 	struct regmap *map = (i2c == chip->client) ? chip->regmap
49 				: chip->regmap_companion;
50 	int ret;
51 
52 	ret = regmap_raw_read(map, reg, buf, count);
53 	return ret;
54 }
55 EXPORT_SYMBOL(pm860x_bulk_read);
56 
57 int pm860x_bulk_write(struct i2c_client *i2c, int reg,
58 		      int count, unsigned char *buf)
59 {
60 	struct pm860x_chip *chip = i2c_get_clientdata(i2c);
61 	struct regmap *map = (i2c == chip->client) ? chip->regmap
62 				: chip->regmap_companion;
63 	int ret;
64 
65 	ret = regmap_raw_write(map, reg, buf, count);
66 	return ret;
67 }
68 EXPORT_SYMBOL(pm860x_bulk_write);
69 
70 int pm860x_set_bits(struct i2c_client *i2c, int reg,
71 		    unsigned char mask, unsigned char data)
72 {
73 	struct pm860x_chip *chip = i2c_get_clientdata(i2c);
74 	struct regmap *map = (i2c == chip->client) ? chip->regmap
75 				: chip->regmap_companion;
76 	int ret;
77 
78 	ret = regmap_update_bits(map, reg, mask, data);
79 	return ret;
80 }
81 EXPORT_SYMBOL(pm860x_set_bits);
82 
83 static int read_device(struct i2c_client *i2c, int reg,
84 		       int bytes, void *dest)
85 {
86 	unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX + 3];
87 	unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX + 2];
88 	struct i2c_adapter *adap = i2c->adapter;
89 	struct i2c_msg msg[2] = {
90 					{
91 						.addr = i2c->addr,
92 						.flags = 0,
93 						.len = 1,
94 						.buf = msgbuf0
95 					},
96 					{	.addr = i2c->addr,
97 						.flags = I2C_M_RD,
98 						.len = 0,
99 						.buf = msgbuf1
100 					},
101 				};
102 	int num = 1, ret = 0;
103 
104 	if (dest == NULL)
105 		return -EINVAL;
106 	msgbuf0[0] = (unsigned char)reg;	/* command */
107 	msg[1].len = bytes;
108 
109 	/* if data needs to read back, num should be 2 */
110 	if (bytes > 0)
111 		num = 2;
112 	ret = adap->algo->master_xfer(adap, msg, num);
113 	memcpy(dest, msgbuf1, bytes);
114 	if (ret < 0)
115 		return ret;
116 	return 0;
117 }
118 
119 static int write_device(struct i2c_client *i2c, int reg,
120 			int bytes, void *src)
121 {
122 	unsigned char buf[2];
123 	struct i2c_adapter *adap = i2c->adapter;
124 	struct i2c_msg msg;
125 	int ret;
126 
127 	buf[0] = (unsigned char)reg;
128 	memcpy(&buf[1], src, bytes);
129 	msg.addr = i2c->addr;
130 	msg.flags = 0;
131 	msg.len = bytes + 1;
132 	msg.buf = buf;
133 
134 	ret = adap->algo->master_xfer(adap, &msg, 1);
135 	if (ret < 0)
136 		return ret;
137 	return 0;
138 }
139 
140 int pm860x_page_reg_write(struct i2c_client *i2c, int reg,
141 			  unsigned char data)
142 {
143 	unsigned char zero;
144 	int ret;
145 
146 	i2c_lock_bus(i2c->adapter, I2C_LOCK_SEGMENT);
147 	read_device(i2c, 0xFA, 0, &zero);
148 	read_device(i2c, 0xFB, 0, &zero);
149 	read_device(i2c, 0xFF, 0, &zero);
150 	ret = write_device(i2c, reg, 1, &data);
151 	read_device(i2c, 0xFE, 0, &zero);
152 	read_device(i2c, 0xFC, 0, &zero);
153 	i2c_unlock_bus(i2c->adapter, I2C_LOCK_SEGMENT);
154 	return ret;
155 }
156 EXPORT_SYMBOL(pm860x_page_reg_write);
157 
158 int pm860x_page_bulk_read(struct i2c_client *i2c, int reg,
159 			  int count, unsigned char *buf)
160 {
161 	unsigned char zero = 0;
162 	int ret;
163 
164 	i2c_lock_bus(i2c->adapter, I2C_LOCK_SEGMENT);
165 	read_device(i2c, 0xfa, 0, &zero);
166 	read_device(i2c, 0xfb, 0, &zero);
167 	read_device(i2c, 0xff, 0, &zero);
168 	ret = read_device(i2c, reg, count, buf);
169 	read_device(i2c, 0xFE, 0, &zero);
170 	read_device(i2c, 0xFC, 0, &zero);
171 	i2c_unlock_bus(i2c->adapter, I2C_LOCK_SEGMENT);
172 	return ret;
173 }
174 EXPORT_SYMBOL(pm860x_page_bulk_read);
175