xref: /openbmc/linux/drivers/mfd/max8925-i2c.c (revision 4800cd83)
1 /*
2  * I2C driver for Maxim MAX8925
3  *
4  * Copyright (C) 2009 Marvell International Ltd.
5  *	Haojian Zhuang <haojian.zhuang@marvell.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14 #include <linux/i2c.h>
15 #include <linux/mfd/max8925.h>
16 #include <linux/slab.h>
17 
18 #define RTC_I2C_ADDR		0x68
19 #define ADC_I2C_ADDR		0x47
20 
21 static inline int max8925_read_device(struct i2c_client *i2c,
22 				      int reg, int bytes, void *dest)
23 {
24 	int ret;
25 
26 	if (bytes > 1)
27 		ret = i2c_smbus_read_i2c_block_data(i2c, reg, bytes, dest);
28 	else {
29 		ret = i2c_smbus_read_byte_data(i2c, reg);
30 		if (ret < 0)
31 			return ret;
32 		*(unsigned char *)dest = (unsigned char)ret;
33 	}
34 	return ret;
35 }
36 
37 static inline int max8925_write_device(struct i2c_client *i2c,
38 				       int reg, int bytes, void *src)
39 {
40 	unsigned char buf[bytes + 1];
41 	int ret;
42 
43 	buf[0] = (unsigned char)reg;
44 	memcpy(&buf[1], src, bytes);
45 
46 	ret = i2c_master_send(i2c, buf, bytes + 1);
47 	if (ret < 0)
48 		return ret;
49 	return 0;
50 }
51 
52 int max8925_reg_read(struct i2c_client *i2c, int reg)
53 {
54 	struct max8925_chip *chip = i2c_get_clientdata(i2c);
55 	unsigned char data = 0;
56 	int ret;
57 
58 	mutex_lock(&chip->io_lock);
59 	ret = max8925_read_device(i2c, reg, 1, &data);
60 	mutex_unlock(&chip->io_lock);
61 
62 	if (ret < 0)
63 		return ret;
64 	else
65 		return (int)data;
66 }
67 EXPORT_SYMBOL(max8925_reg_read);
68 
69 int max8925_reg_write(struct i2c_client *i2c, int reg,
70 		unsigned char data)
71 {
72 	struct max8925_chip *chip = i2c_get_clientdata(i2c);
73 	int ret;
74 
75 	mutex_lock(&chip->io_lock);
76 	ret = max8925_write_device(i2c, reg, 1, &data);
77 	mutex_unlock(&chip->io_lock);
78 
79 	return ret;
80 }
81 EXPORT_SYMBOL(max8925_reg_write);
82 
83 int max8925_bulk_read(struct i2c_client *i2c, int reg,
84 		int count, unsigned char *buf)
85 {
86 	struct max8925_chip *chip = i2c_get_clientdata(i2c);
87 	int ret;
88 
89 	mutex_lock(&chip->io_lock);
90 	ret = max8925_read_device(i2c, reg, count, buf);
91 	mutex_unlock(&chip->io_lock);
92 
93 	return ret;
94 }
95 EXPORT_SYMBOL(max8925_bulk_read);
96 
97 int max8925_bulk_write(struct i2c_client *i2c, int reg,
98 		int count, unsigned char *buf)
99 {
100 	struct max8925_chip *chip = i2c_get_clientdata(i2c);
101 	int ret;
102 
103 	mutex_lock(&chip->io_lock);
104 	ret = max8925_write_device(i2c, reg, count, buf);
105 	mutex_unlock(&chip->io_lock);
106 
107 	return ret;
108 }
109 EXPORT_SYMBOL(max8925_bulk_write);
110 
111 int max8925_set_bits(struct i2c_client *i2c, int reg,
112 		unsigned char mask, unsigned char data)
113 {
114 	struct max8925_chip *chip = i2c_get_clientdata(i2c);
115 	unsigned char value;
116 	int ret;
117 
118 	mutex_lock(&chip->io_lock);
119 	ret = max8925_read_device(i2c, reg, 1, &value);
120 	if (ret < 0)
121 		goto out;
122 	value &= ~mask;
123 	value |= data;
124 	ret = max8925_write_device(i2c, reg, 1, &value);
125 out:
126 	mutex_unlock(&chip->io_lock);
127 	return ret;
128 }
129 EXPORT_SYMBOL(max8925_set_bits);
130 
131 
132 static const struct i2c_device_id max8925_id_table[] = {
133 	{ "max8925", 0 },
134 	{ },
135 };
136 MODULE_DEVICE_TABLE(i2c, max8925_id_table);
137 
138 static int __devinit max8925_probe(struct i2c_client *client,
139 				   const struct i2c_device_id *id)
140 {
141 	struct max8925_platform_data *pdata = client->dev.platform_data;
142 	static struct max8925_chip *chip;
143 
144 	if (!pdata) {
145 		pr_info("%s: platform data is missing\n", __func__);
146 		return -EINVAL;
147 	}
148 
149 	chip = kzalloc(sizeof(struct max8925_chip), GFP_KERNEL);
150 	if (chip == NULL)
151 		return -ENOMEM;
152 	chip->i2c = client;
153 	chip->dev = &client->dev;
154 	i2c_set_clientdata(client, chip);
155 	dev_set_drvdata(chip->dev, chip);
156 	mutex_init(&chip->io_lock);
157 
158 	chip->rtc = i2c_new_dummy(chip->i2c->adapter, RTC_I2C_ADDR);
159 	i2c_set_clientdata(chip->rtc, chip);
160 
161 	chip->adc = i2c_new_dummy(chip->i2c->adapter, ADC_I2C_ADDR);
162 	i2c_set_clientdata(chip->adc, chip);
163 
164 	max8925_device_init(chip, pdata);
165 
166 	return 0;
167 }
168 
169 static int __devexit max8925_remove(struct i2c_client *client)
170 {
171 	struct max8925_chip *chip = i2c_get_clientdata(client);
172 
173 	max8925_device_exit(chip);
174 	i2c_unregister_device(chip->adc);
175 	i2c_unregister_device(chip->rtc);
176 	kfree(chip);
177 	return 0;
178 }
179 
180 static struct i2c_driver max8925_driver = {
181 	.driver	= {
182 		.name	= "max8925",
183 		.owner	= THIS_MODULE,
184 	},
185 	.probe		= max8925_probe,
186 	.remove		= __devexit_p(max8925_remove),
187 	.id_table	= max8925_id_table,
188 };
189 
190 static int __init max8925_i2c_init(void)
191 {
192 	int ret;
193 
194 	ret = i2c_add_driver(&max8925_driver);
195 	if (ret != 0)
196 		pr_err("Failed to register MAX8925 I2C driver: %d\n", ret);
197 	return ret;
198 }
199 subsys_initcall(max8925_i2c_init);
200 
201 static void __exit max8925_i2c_exit(void)
202 {
203 	i2c_del_driver(&max8925_driver);
204 }
205 module_exit(max8925_i2c_exit);
206 
207 MODULE_DESCRIPTION("I2C Driver for Maxim 8925");
208 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
209 MODULE_LICENSE("GPL");
210