/drivers/mfd/max8925-i2c.c

  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
 21static 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
 37static 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
 52int 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}
 67EXPORT_SYMBOL(max8925_reg_read);
 68
 69int 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}
 81EXPORT_SYMBOL(max8925_reg_write);
 82
 83int 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}
 95EXPORT_SYMBOL(max8925_bulk_read);
 96
 97int 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}
109EXPORT_SYMBOL(max8925_bulk_write);
110
111int 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);
125out:
126	mutex_unlock(&chip->io_lock);
127	return ret;
128}
129EXPORT_SYMBOL(max8925_set_bits);
130
131
132static const struct i2c_device_id max8925_id_table[] = {
133	{ "max8925", 0 },
134	{ },
135};
136MODULE_DEVICE_TABLE(i2c, max8925_id_table);
137
138static 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
169static 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
180static 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
190static 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}
199subsys_initcall(max8925_i2c_init);
200
201static void __exit max8925_i2c_exit(void)
202{
203	i2c_del_driver(&max8925_driver);
204}
205module_exit(max8925_i2c_exit);
206
207MODULE_DESCRIPTION("I2C Driver for Maxim 8925");
208MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
209MODULE_LICENSE("GPL");