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
  31
  32 static int tps6507x_i2c_read_device(struct tps6507x_dev *tps6507x, char reg,
  33                                   int bytes, void *dest)
  34 {
  35         struct i2c_client *i2c = tps6507x->i2c_client;
  36         struct i2c_msg xfer[2];
  37         int ret;
  38
  39         /* Write register */
  40         xfer[0].addr = i2c->addr;
  41         xfer[0].flags = 0;
  42         xfer[0].len = 1;
  43         xfer[0].buf = &reg;
  44
  45         /* Read data */
  46         xfer[1].addr = i2c->addr;
  47         xfer[1].flags = I2C_M_RD;
  48         xfer[1].len = bytes;
  49         xfer[1].buf = dest;
  50
  51         ret = i2c_transfer(i2c->adapter, xfer, 2);
  52         if (ret == 2)
  53                 ret = 0;
  54         else if (ret >= 0)
  55                 ret = -EIO;
  56
  57         return ret;
  58 }
  59
  60 static int tps6507x_i2c_write_device(struct tps6507x_dev *tps6507x, char reg,
  61                                    int bytes, void *src)
  62 {
  63         struct i2c_client *i2c = tps6507x->i2c_client;
  64         /* we add 1 byte for device register */
  65         u8 msg[TPS6507X_MAX_REGISTER + 1];
  66         int ret;
  67
  68         if (bytes > (TPS6507X_MAX_REGISTER + 1))
  69                 return -EINVAL;
  70
  71         msg[0] = reg;
  72         memcpy(&msg[1], src, bytes);
  73
  74         ret = i2c_master_send(i2c, msg, bytes + 1);
  75         if (ret < 0)
  76                 return ret;
  77         if (ret != bytes + 1)
  78                 return -EIO;
  79         return 0;
  80 }
  81
  82 static int tps6507x_i2c_probe(struct i2c_client *i2c,
  83                             const struct i2c_device_id *id)
  84 {
  85         struct tps6507x_dev *tps6507x;
  86         int ret = 0;
  87
  88         tps6507x = kzalloc(sizeof(struct tps6507x_dev), GFP_KERNEL);
  89         if (tps6507x == NULL) {
  90                 kfree(i2c);
  91                 return -ENOMEM;
  92         }
  93
  94         i2c_set_clientdata(i2c, tps6507x);
  95         tps6507x->dev = &i2c->dev;
  96         tps6507x->i2c_client = i2c;
  97         tps6507x->read_dev = tps6507x_i2c_read_device;
  98         tps6507x->write_dev = tps6507x_i2c_write_device;
  99
 100         ret = mfd_add_devices(tps6507x->dev, -1,
 101                               tps6507x_devs, ARRAY_SIZE(tps6507x_devs),
 102                               NULL, 0);
 103
 104         if (ret < 0)
 105                 goto err;
 106
 107         return ret;
 108
 109 err:
 110         mfd_remove_devices(tps6507x->dev);
 111         kfree(tps6507x);
 112         return ret;
 113 }
 114
 115 static int tps6507x_i2c_remove(struct i2c_client *i2c)
 116 {
 117         struct tps6507x_dev *tps6507x = i2c_get_clientdata(i2c);
 118
 119         mfd_remove_devices(tps6507x->dev);
 120         kfree(tps6507x);
 121
 122         return 0;
 123 }
 124
 125 static const struct i2c_device_id tps6507x_i2c_id[] = {
 126        { "tps6507x", 0 },
 127        { }
 128 };
 129 MODULE_DEVICE_TABLE(i2c, tps6507x_i2c_id);
 130
 131
 132 static struct i2c_driver tps6507x_i2c_driver = {
 133         .driver = {
 134                    .name = "tps6507x",
 135                    .owner = THIS_MODULE,
 136         },
 137         .probe = tps6507x_i2c_probe,
 138         .remove = tps6507x_i2c_remove,
 139         .id_table = tps6507x_i2c_id,
 140 };
 141
 142 static int __init tps6507x_i2c_init(void)
 143 {
 144         return i2c_add_driver(&tps6507x_i2c_driver);
 145 }
 146 /* init early so consumer devices can complete system boot */
 147 subsys_initcall(tps6507x_i2c_init);
 148
 149 static void __exit tps6507x_i2c_exit(void)
 150 {
 151         i2c_del_driver(&tps6507x_i2c_driver);
 152 }
 153 module_exit(tps6507x_i2c_exit);
 154
 155 MODULE_DESCRIPTION("TPS6507x chip family multi-function driver");
 156 MODULE_LICENSE("GPL");