linux/drivers/mfd/max8925-i2c.c
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   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 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        device_init_wakeup(&client->dev, 1);
 165
 166        max8925_device_init(chip, pdata);
 167
 168        return 0;
 169}
 170
 171static int max8925_remove(struct i2c_client *client)
 172{
 173        struct max8925_chip *chip = i2c_get_clientdata(client);
 174
 175        max8925_device_exit(chip);
 176        i2c_unregister_device(chip->adc);
 177        i2c_unregister_device(chip->rtc);
 178        kfree(chip);
 179        return 0;
 180}
 181
 182#ifdef CONFIG_PM_SLEEP
 183static int max8925_suspend(struct device *dev)
 184{
 185        struct i2c_client *client = container_of(dev, struct i2c_client, dev);
 186        struct max8925_chip *chip = i2c_get_clientdata(client);
 187
 188        if (device_may_wakeup(dev) && chip->wakeup_flag)
 189                enable_irq_wake(chip->core_irq);
 190        return 0;
 191}
 192
 193static int max8925_resume(struct device *dev)
 194{
 195        struct i2c_client *client = container_of(dev, struct i2c_client, dev);
 196        struct max8925_chip *chip = i2c_get_clientdata(client);
 197
 198        if (device_may_wakeup(dev) && chip->wakeup_flag)
 199                disable_irq_wake(chip->core_irq);
 200        return 0;
 201}
 202#endif
 203
 204static SIMPLE_DEV_PM_OPS(max8925_pm_ops, max8925_suspend, max8925_resume);
 205
 206static struct i2c_driver max8925_driver = {
 207        .driver = {
 208                .name   = "max8925",
 209                .owner  = THIS_MODULE,
 210                .pm     = &max8925_pm_ops,
 211        },
 212        .probe          = max8925_probe,
 213        .remove         = max8925_remove,
 214        .id_table       = max8925_id_table,
 215};
 216
 217static int __init max8925_i2c_init(void)
 218{
 219        int ret;
 220
 221        ret = i2c_add_driver(&max8925_driver);
 222        if (ret != 0)
 223                pr_err("Failed to register MAX8925 I2C driver: %d\n", ret);
 224        return ret;
 225}
 226subsys_initcall(max8925_i2c_init);
 227
 228static void __exit max8925_i2c_exit(void)
 229{
 230        i2c_del_driver(&max8925_driver);
 231}
 232module_exit(max8925_i2c_exit);
 233
 234MODULE_DESCRIPTION("I2C Driver for Maxim 8925");
 235MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
 236MODULE_LICENSE("GPL");
 237
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