drivers/mfd/tps6507x.c

   1 /*
   2  * tps6507x.c  --  TPS6507x chip family multi-function driver
   3  *
   4  *  Copyright (c) 2010 RidgeRun (todd.fischer@ridgerun.com)
   5  *
   6  * Author: Todd Fischer
   7  *         todd.fischer@ridgerun.com
   8  *
   9  * Credits:
  10  *
  11  *    Using code from wm831x-*.c, wm8400-core, Wolfson Microelectronics PLC.
  12  *
  13  * For licencing details see kernel-base/COPYING
  14  *
  15  */
  16
  17 #include <linux/module.h>
  18 #include <linux/moduleparam.h>
  19 #include <linux/init.h>
  20 #include <linux/slab.h>
  21 #include <linux/i2c.h>
  22 #include <linux/mfd/core.h>
  23 #include <linux/mfd/tps6507x.h>
  24
  25 static struct mfd_cell tps6507x_devs[] = {
  26         {
  27                 .name = "tps6507x-pmic",
  28         },
  29         {
  30                 .name = "tps6507x-ts",
  31         },
  32 };
  33
  34
  35 static int tps6507x_i2c_read_device(struct tps6507x_dev *tps6507x, char reg,
  36                                   int bytes, void *dest)
  37 {
  38         struct i2c_client *i2c = tps6507x->i2c_client;
  39         struct i2c_msg xfer[2];
  40         int ret;
  41
  42         /* Write register */
  43         xfer[0].addr = i2c->addr;
  44         xfer[0].flags = 0;
  45         xfer[0].len = 1;
  46         xfer[0].buf = &reg;
  47
  48         /* Read data */
  49         xfer[1].addr = i2c->addr;
  50         xfer[1].flags = I2C_M_RD;
  51         xfer[1].len = bytes;
  52         xfer[1].buf = dest;
  53
  54         ret = i2c_transfer(i2c->adapter, xfer, 2);
  55         if (ret == 2)
  56                 ret = 0;
  57         else if (ret >= 0)
  58                 ret = -EIO;
  59
  60         return ret;
  61 }
  62
  63 static int tps6507x_i2c_write_device(struct tps6507x_dev *tps6507x, char reg,
  64                                    int bytes, void *src)
  65 {
  66         struct i2c_client *i2c = tps6507x->i2c_client;
  67         /* we add 1 byte for device register */
  68         u8 msg[TPS6507X_MAX_REGISTER + 1];
  69         int ret;
  70
  71         if (bytes > TPS6507X_MAX_REGISTER)
  72                 return -EINVAL;
  73
  74         msg[0] = reg;
  75         memcpy(&msg[1], src, bytes);
  76
  77         ret = i2c_master_send(i2c, msg, bytes + 1);
  78         if (ret < 0)
  79                 return ret;
  80         if (ret != bytes + 1)
  81                 return -EIO;
  82         return 0;
  83 }
  84
  85 static int tps6507x_i2c_probe(struct i2c_client *i2c,
  86                             const struct i2c_device_id *id)
  87 {
  88         struct tps6507x_dev *tps6507x;
  89         int ret = 0;
  90
  91         tps6507x = kzalloc(sizeof(struct tps6507x_dev), GFP_KERNEL);
  92         if (tps6507x == NULL)
  93                 return -ENOMEM;
  94
  95         i2c_set_clientdata(i2c, tps6507x);
  96         tps6507x->dev = &i2c->dev;
  97         tps6507x->i2c_client = i2c;
  98         tps6507x->read_dev = tps6507x_i2c_read_device;
  99         tps6507x->write_dev = tps6507x_i2c_write_device;
 100
 101         ret = mfd_add_devices(tps6507x->dev, -1,
 102                               tps6507x_devs, ARRAY_SIZE(tps6507x_devs),
 103                               NULL, 0);
 104
 105         if (ret < 0)
 106                 goto err;
 107
 108         return ret;
 109
 110 err:
 111         mfd_remove_devices(tps6507x->dev);
 112         kfree(tps6507x);
 113         return ret;
 114 }
 115
 116 static int tps6507x_i2c_remove(struct i2c_client *i2c)
 117 {
 118         struct tps6507x_dev *tps6507x = i2c_get_clientdata(i2c);
 119
 120         mfd_remove_devices(tps6507x->dev);
 121         kfree(tps6507x);
 122
 123         return 0;
 124 }
 125
 126 static const struct i2c_device_id tps6507x_i2c_id[] = {
 127        { "tps6507x", 0 },
 128        { }
 129 };
 130 MODULE_DEVICE_TABLE(i2c, tps6507x_i2c_id);
 131
 132
 133 static struct i2c_driver tps6507x_i2c_driver = {
 134         .driver = {
 135                    .name = "tps6507x",
 136                    .owner = THIS_MODULE,
 137         },
 138         .probe = tps6507x_i2c_probe,
 139         .remove = tps6507x_i2c_remove,
 140         .id_table = tps6507x_i2c_id,
 141 };
 142
 143 static int __init tps6507x_i2c_init(void)
 144 {
 145         return i2c_add_driver(&tps6507x_i2c_driver);
 146 }
 147 /* init early so consumer devices can complete system boot */
 148 subsys_initcall(tps6507x_i2c_init);
 149
 150 static void __exit tps6507x_i2c_exit(void)
 151 {
 152         i2c_del_driver(&tps6507x_i2c_driver);
 153 }
 154 module_exit(tps6507x_i2c_exit);
 155
 156 MODULE_DESCRIPTION("TPS6507x chip family multi-function driver");
 157 MODULE_LICENSE("GPL");