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 + 1))
  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                 kfree(i2c);
  94                 return -ENOMEM;
  95         }
  96
  97         i2c_set_clientdata(i2c, tps6507x);
  98         tps6507x->dev = &i2c->dev;
  99         tps6507x->i2c_client = i2c;
 100         tps6507x->read_dev = tps6507x_i2c_read_device;
 101         tps6507x->write_dev = tps6507x_i2c_write_device;
 102
 103         ret = mfd_add_devices(tps6507x->dev, -1,
 104                               tps6507x_devs, ARRAY_SIZE(tps6507x_devs),
 105                               NULL, 0);
 106
 107         if (ret < 0)
 108                 goto err;
 109
 110         return ret;
 111
 112 err:
 113         mfd_remove_devices(tps6507x->dev);
 114         kfree(tps6507x);
 115         return ret;
 116 }
 117
 118 static int tps6507x_i2c_remove(struct i2c_client *i2c)
 119 {
 120         struct tps6507x_dev *tps6507x = i2c_get_clientdata(i2c);
 121
 122         mfd_remove_devices(tps6507x->dev);
 123         kfree(tps6507x);
 124
 125         return 0;
 126 }
 127
 128 static const struct i2c_device_id tps6507x_i2c_id[] = {
 129        { "tps6507x", 0 },
 130        { }
 131 };
 132 MODULE_DEVICE_TABLE(i2c, tps6507x_i2c_id);
 133
 134
 135 static struct i2c_driver tps6507x_i2c_driver = {
 136         .driver = {
 137                    .name = "tps6507x",
 138                    .owner = THIS_MODULE,
 139         },
 140         .probe = tps6507x_i2c_probe,
 141         .remove = tps6507x_i2c_remove,
 142         .id_table = tps6507x_i2c_id,
 143 };
 144
 145 static int __init tps6507x_i2c_init(void)
 146 {
 147         return i2c_add_driver(&tps6507x_i2c_driver);
 148 }
 149 /* init early so consumer devices can complete system boot */
 150 subsys_initcall(tps6507x_i2c_init);
 151
 152 static void __exit tps6507x_i2c_exit(void)
 153 {
 154         i2c_del_driver(&tps6507x_i2c_driver);
 155 }
 156 module_exit(tps6507x_i2c_exit);
 157
 158 MODULE_DESCRIPTION("TPS6507x chip family multi-function driver");
 159 MODULE_LICENSE("GPL");