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/of.h>
  23 #include <linux/mfd/core.h>
  24 #include <linux/mfd/tps6507x.h>
  25
  26 static const struct mfd_cell tps6507x_devs[] = {
  27         {
  28                 .name = "tps6507x-pmic",
  29         },
  30         {
  31                 .name = "tps6507x-ts",
  32         },
  33 };
  34
  35
  36 static int tps6507x_i2c_read_device(struct tps6507x_dev *tps6507x, char reg,
  37                                   int bytes, void *dest)
  38 {
  39         struct i2c_client *i2c = tps6507x->i2c_client;
  40         struct i2c_msg xfer[2];
  41         int ret;
  42
  43         /* Write register */
  44         xfer[0].addr = i2c->addr;
  45         xfer[0].flags = 0;
  46         xfer[0].len = 1;
  47         xfer[0].buf = &reg;
  48
  49         /* Read data */
  50         xfer[1].addr = i2c->addr;
  51         xfer[1].flags = I2C_M_RD;
  52         xfer[1].len = bytes;
  53         xfer[1].buf = dest;
  54
  55         ret = i2c_transfer(i2c->adapter, xfer, 2);
  56         if (ret == 2)
  57                 ret = 0;
  58         else if (ret >= 0)
  59                 ret = -EIO;
  60
  61         return ret;
  62 }
  63
  64 static int tps6507x_i2c_write_device(struct tps6507x_dev *tps6507x, char reg,
  65                                    int bytes, void *src)
  66 {
  67         struct i2c_client *i2c = tps6507x->i2c_client;
  68         /* we add 1 byte for device register */
  69         u8 msg[TPS6507X_MAX_REGISTER + 1];
  70         int ret;
  71
  72         if (bytes > TPS6507X_MAX_REGISTER)
  73                 return -EINVAL;
  74
  75         msg[0] = reg;
  76         memcpy(&msg[1], src, bytes);
  77
  78         ret = i2c_master_send(i2c, msg, bytes + 1);
  79         if (ret < 0)
  80                 return ret;
  81         if (ret != bytes + 1)
  82                 return -EIO;
  83         return 0;
  84 }
  85
  86 static int tps6507x_i2c_probe(struct i2c_client *i2c)
  87 {
  88         struct tps6507x_dev *tps6507x;
  89
  90         tps6507x = devm_kzalloc(&i2c->dev, sizeof(struct tps6507x_dev),
  91                                 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         return devm_mfd_add_devices(tps6507x->dev, -1, tps6507x_devs,
 102                                     ARRAY_SIZE(tps6507x_devs), NULL, 0, NULL);
 103 }
 104
 105 static const struct i2c_device_id tps6507x_i2c_id[] = {
 106         { "tps6507x", 0 },
 107         { }
 108 };
 109 MODULE_DEVICE_TABLE(i2c, tps6507x_i2c_id);
 110
 111 #ifdef CONFIG_OF
 112 static const struct of_device_id tps6507x_of_match[] = {
 113         {.compatible = "ti,tps6507x", },
 114         {},
 115 };
 116 MODULE_DEVICE_TABLE(of, tps6507x_of_match);
 117 #endif
 118
 119 static struct i2c_driver tps6507x_i2c_driver = {
 120         .driver = {
 121                    .name = "tps6507x",
 122                    .of_match_table = of_match_ptr(tps6507x_of_match),
 123         },
 124         .probe = tps6507x_i2c_probe,
 125         .id_table = tps6507x_i2c_id,
 126 };
 127
 128 static int __init tps6507x_i2c_init(void)
 129 {
 130         return i2c_add_driver(&tps6507x_i2c_driver);
 131 }
 132 /* init early so consumer devices can complete system boot */
 133 subsys_initcall(tps6507x_i2c_init);
 134
 135 static void __exit tps6507x_i2c_exit(void)
 136 {
 137         i2c_del_driver(&tps6507x_i2c_driver);
 138 }
 139 module_exit(tps6507x_i2c_exit);
 140
 141 MODULE_DESCRIPTION("TPS6507x chip family multi-function driver");
 142 MODULE_LICENSE("GPL");