diff options
Diffstat (limited to 'drivers/mfd/max8925-i2c.c')
| -rw-r--r-- | drivers/mfd/max8925-i2c.c | 210 |
1 files changed, 210 insertions, 0 deletions
diff --git a/drivers/mfd/max8925-i2c.c b/drivers/mfd/max8925-i2c.c new file mode 100644 index 00000000000..942068e730f --- /dev/null +++ b/drivers/mfd/max8925-i2c.c @@ -0,0 +1,210 @@ +/* + * I2C driver for Maxim MAX8925 + * + * Copyright (C) 2009 Marvell International Ltd. + * Haojian Zhuang <haojian.zhuang@marvell.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/i2c.h> +#include <linux/mfd/max8925.h> + +static inline int max8925_read_device(struct i2c_client *i2c, + int reg, int bytes, void *dest) +{ + unsigned char data; + unsigned char *buf; + int ret; + + buf = kzalloc(bytes + 1, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + data = (unsigned char)reg; + ret = i2c_master_send(i2c, &data, 1); + if (ret < 0) + return ret; + + ret = i2c_master_recv(i2c, buf, bytes + 1); + if (ret < 0) + return ret; + memcpy(dest, buf, bytes); + return 0; +} + +static inline int max8925_write_device(struct i2c_client *i2c, + int reg, int bytes, void *src) +{ + unsigned char buf[bytes + 1]; + int ret; + + buf[0] = (unsigned char)reg; + memcpy(&buf[1], src, bytes); + + ret = i2c_master_send(i2c, buf, bytes + 1); + if (ret < 0) + return ret; + return 0; +} + +int max8925_reg_read(struct i2c_client *i2c, int reg) +{ + struct max8925_chip *chip = i2c_get_clientdata(i2c); + unsigned char data; + int ret; + + mutex_lock(&chip->io_lock); + ret = max8925_read_device(i2c, reg, 1, &data); + mutex_unlock(&chip->io_lock); + + if (ret < 0) + return ret; + else + return (int)data; +} +EXPORT_SYMBOL(max8925_reg_read); + +int max8925_reg_write(struct i2c_client *i2c, int reg, + unsigned char data) +{ + struct max8925_chip *chip = i2c_get_clientdata(i2c); + int ret; + + mutex_lock(&chip->io_lock); + ret = max8925_write_device(i2c, reg, 1, &data); + mutex_unlock(&chip->io_lock); + + return ret; +} +EXPORT_SYMBOL(max8925_reg_write); + +int max8925_bulk_read(struct i2c_client *i2c, int reg, + int count, unsigned char *buf) +{ + struct max8925_chip *chip = i2c_get_clientdata(i2c); + int ret; + + mutex_lock(&chip->io_lock); + ret = max8925_read_device(i2c, reg, count, buf); + mutex_unlock(&chip->io_lock); + + return ret; +} +EXPORT_SYMBOL(max8925_bulk_read); + +int max8925_bulk_write(struct i2c_client *i2c, int reg, + int count, unsigned char *buf) +{ + struct max8925_chip *chip = i2c_get_clientdata(i2c); + int ret; + + mutex_lock(&chip->io_lock); + ret = max8925_write_device(i2c, reg, count, buf); + mutex_unlock(&chip->io_lock); + + return ret; +} +EXPORT_SYMBOL(max8925_bulk_write); + +int max8925_set_bits(struct i2c_client *i2c, int reg, + unsigned char mask, unsigned char data) +{ + struct max8925_chip *chip = i2c_get_clientdata(i2c); + unsigned char value; + int ret; + + mutex_lock(&chip->io_lock); + ret = max8925_read_device(i2c, reg, 1, &value); + if (ret < 0) + goto out; + value &= ~mask; + value |= data; + ret = max8925_write_device(i2c, reg, 1, &value); +out: + mutex_unlock(&chip->io_lock); + return ret; +} +EXPORT_SYMBOL(max8925_set_bits); + + +static const struct i2c_device_id max8925_id_table[] = { + { "max8925", 0 }, + {} +}; +MODULE_DEVICE_TABLE(i2c, max8925_id_table); + +static int __devinit max8925_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct max8925_platform_data *pdata = client->dev.platform_data; + struct max8925_chip *chip; + + if (!pdata) { + pr_info("%s: platform data is missing\n", __func__); + return -EINVAL; + } + if ((pdata->chip_id <= MAX8925_INVALID) + || (pdata->chip_id >= MAX8925_MAX)) { + pr_info("#%s: wrong chip identification\n", __func__); + return -EINVAL; + } + + chip = kzalloc(sizeof(struct max8925_chip), GFP_KERNEL); + if (chip == NULL) + return -ENOMEM; + chip->i2c = client; + chip->chip_id = pdata->chip_id; + i2c_set_clientdata(client, chip); + chip->dev = &client->dev; + mutex_init(&chip->io_lock); + dev_set_drvdata(chip->dev, chip); + max8925_device_init(chip, pdata); + + return 0; +} + +static int __devexit max8925_remove(struct i2c_client *client) +{ + struct max8925_chip *chip = i2c_get_clientdata(client); + + max8925_device_exit(chip); + i2c_set_clientdata(client, NULL); + kfree(chip); + return 0; +} + +static struct i2c_driver max8925_driver = { + .driver = { + .name = "max8925", + .owner = THIS_MODULE, + }, + .probe = max8925_probe, + .remove = __devexit_p(max8925_remove), + .id_table = max8925_id_table, +}; + +static int __init max8925_i2c_init(void) +{ + int ret; + + ret = i2c_add_driver(&max8925_driver); + if (ret != 0) + pr_err("Failed to register MAX8925 I2C driver: %d\n", ret); + return ret; +} +subsys_initcall(max8925_i2c_init); + +static void __exit max8925_i2c_exit(void) +{ + i2c_del_driver(&max8925_driver); +} +module_exit(max8925_i2c_exit); + +MODULE_DESCRIPTION("I2C Driver for Maxim 8925"); +MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>"); +MODULE_LICENSE("GPL"); |