drivers/mfd/max8998.c

   1 /*
   2  * max8698.c - mfd core driver for the Maxim 8998
   3  *
   4  *  Copyright (C) 2009-2010 Samsung Electronics
   5  *  Kyungmin Park <kyungmin.park@samsung.com>
   6  *  Marek Szyprowski <m.szyprowski@samsung.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  */
  22
  23 #include <linux/module.h>
  24 #include <linux/moduleparam.h>
  25 #include <linux/init.h>
  26 #include <linux/slab.h>
  27 #include <linux/i2c.h>
  28 #include <linux/mutex.h>
  29 #include <linux/mfd/core.h>
  30 #include <linux/mfd/max8998.h>
  31 #include <linux/mfd/max8998-private.h>
  32
  33 static struct mfd_cell max8998_devs[] = {
  34         {
  35                 .name = "max8998-pmic",
  36         }
  37 };
  38
  39 static int max8998_i2c_device_read(struct max8998_dev *max8998, u8 reg, u8 *dest)
  40 {
  41         struct i2c_client *client = max8998->i2c_client;
  42         int ret;
  43
  44         mutex_lock(&max8998->iolock);
  45         ret = i2c_smbus_read_byte_data(client, reg);
  46         mutex_unlock(&max8998->iolock);
  47         if (ret < 0)
  48                 return ret;
  49
  50         ret &= 0xff;
  51         *dest = ret;
  52         return 0;
  53 }
  54
  55 static int max8998_i2c_device_write(struct max8998_dev *max8998, u8 reg, u8 value)
  56 {
  57         struct i2c_client *client = max8998->i2c_client;
  58         int ret;
  59
  60         mutex_lock(&max8998->iolock);
  61         ret = i2c_smbus_write_byte_data(client, reg, value);
  62         mutex_unlock(&max8998->iolock);
  63         return ret;
  64 }
  65
  66 static int max8998_i2c_device_update(struct max8998_dev *max8998, u8 reg,
  67                                      u8 val, u8 mask)
  68 {
  69         struct i2c_client *client = max8998->i2c_client;
  70         int ret;
  71
  72         mutex_lock(&max8998->iolock);
  73         ret = i2c_smbus_read_byte_data(client, reg);
  74         if (ret >= 0) {
  75                 u8 old_val = ret & 0xff;
  76                 u8 new_val = (val & mask) | (old_val & (~mask));
  77                 ret = i2c_smbus_write_byte_data(client, reg, new_val);
  78                 if (ret >= 0)
  79                         ret = 0;
  80         }
  81         mutex_unlock(&max8998->iolock);
  82         return ret;
  83 }
  84
  85 static int max8998_i2c_probe(struct i2c_client *i2c,
  86                             const struct i2c_device_id *id)
  87 {
  88         struct max8998_dev *max8998;
  89         int ret = 0;
  90
  91         max8998 = kzalloc(sizeof(struct max8998_dev), GFP_KERNEL);
  92         if (max8998 == NULL)
  93                 return -ENOMEM;
  94
  95         i2c_set_clientdata(i2c, max8998);
  96         max8998->dev = &i2c->dev;
  97         max8998->i2c_client = i2c;
  98         max8998->dev_read = max8998_i2c_device_read;
  99         max8998->dev_write = max8998_i2c_device_write;
 100         max8998->dev_update = max8998_i2c_device_update;
 101         mutex_init(&max8998->iolock);
 102
 103         ret = mfd_add_devices(max8998->dev, -1,
 104                               max8998_devs, ARRAY_SIZE(max8998_devs),
 105                               NULL, 0);
 106         if (ret < 0)
 107                 goto err;
 108
 109         return ret;
 110
 111 err:
 112         mfd_remove_devices(max8998->dev);
 113         kfree(max8998);
 114         return ret;
 115 }
 116
 117 static int max8998_i2c_remove(struct i2c_client *i2c)
 118 {
 119         struct max8998_dev *max8998 = i2c_get_clientdata(i2c);
 120
 121         mfd_remove_devices(max8998->dev);
 122         kfree(max8998);
 123
 124         return 0;
 125 }
 126
 127 static const struct i2c_device_id max8998_i2c_id[] = {
 128        { "max8998", 0 },
 129        { }
 130 };
 131 MODULE_DEVICE_TABLE(i2c, max8998_i2c_id);
 132
 133 static struct i2c_driver max8998_i2c_driver = {
 134         .driver = {
 135                    .name = "max8998",
 136                    .owner = THIS_MODULE,
 137         },
 138         .probe = max8998_i2c_probe,
 139         .remove = max8998_i2c_remove,
 140         .id_table = max8998_i2c_id,
 141 };
 142
 143 static int __init max8998_i2c_init(void)
 144 {
 145         return i2c_add_driver(&max8998_i2c_driver);
 146 }
 147 /* init early so consumer devices can complete system boot */
 148 subsys_initcall(max8998_i2c_init);
 149
 150 static void __exit max8998_i2c_exit(void)
 151 {
 152         i2c_del_driver(&max8998_i2c_driver);
 153 }
 154 module_exit(max8998_i2c_exit);
 155
 156 MODULE_DESCRIPTION("MAXIM 8998 multi-function core driver");
 157 MODULE_AUTHOR("Kyungmin Park <kyungmin.park@samsung.com>");
 158 MODULE_LICENSE("GPL");