LXR linux/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/of_device.h>
  24#include <linux/mfd/core.h>
  25#include <linux/mfd/tps6507x.h>
  26
  27static const struct mfd_cell tps6507x_devs[] = {
  28        {
  29                .name = "tps6507x-pmic",
  30        },
  31        {
  32                .name = "tps6507x-ts",
  33        },
  34};
  35
  36
  37static int tps6507x_i2c_read_device(struct tps6507x_dev *tps6507x, char reg,
  38                                  int bytes, void *dest)
  39{
  40        struct i2c_client *i2c = tps6507x->i2c_client;
  41        struct i2c_msg xfer[2];
  42        int ret;
  43
  44        /* Write register */
  45        xfer[0].addr = i2c->addr;
  46        xfer[0].flags = 0;
  47        xfer[0].len = 1;
  48        xfer[0].buf = &reg;
  49
  50        /* Read data */
  51        xfer[1].addr = i2c->addr;
  52        xfer[1].flags = I2C_M_RD;
  53        xfer[1].len = bytes;
  54        xfer[1].buf = dest;
  55
  56        ret = i2c_transfer(i2c->adapter, xfer, 2);
  57        if (ret == 2)
  58                ret = 0;
  59        else if (ret >= 0)
  60                ret = -EIO;
  61
  62        return ret;
  63}
  64
  65static int tps6507x_i2c_write_device(struct tps6507x_dev *tps6507x, char reg,
  66                                   int bytes, void *src)
  67{
  68        struct i2c_client *i2c = tps6507x->i2c_client;
  69        /* we add 1 byte for device register */
  70        u8 msg[TPS6507X_MAX_REGISTER + 1];
  71        int ret;
  72
  73        if (bytes > TPS6507X_MAX_REGISTER)
  74                return -EINVAL;
  75
  76        msg[0] = reg;
  77        memcpy(&msg[1], src, bytes);
  78
  79        ret = i2c_master_send(i2c, msg, bytes + 1);
  80        if (ret < 0)
  81                return ret;
  82        if (ret != bytes + 1)
  83                return -EIO;
  84        return 0;
  85}
  86
  87static int tps6507x_i2c_probe(struct i2c_client *i2c,
  88                            const struct i2c_device_id *id)
  89{
  90        struct tps6507x_dev *tps6507x;
  91
  92        tps6507x = devm_kzalloc(&i2c->dev, sizeof(struct tps6507x_dev),
  93                                GFP_KERNEL);
  94        if (tps6507x == NULL)
  95                return -ENOMEM;
  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        return devm_mfd_add_devices(tps6507x->dev, -1, tps6507x_devs,
 104                                    ARRAY_SIZE(tps6507x_devs), NULL, 0, NULL);
 105}
 106
 107static const struct i2c_device_id tps6507x_i2c_id[] = {
 108        { "tps6507x", 0 },
 109        { }
 110};
 111MODULE_DEVICE_TABLE(i2c, tps6507x_i2c_id);
 112
 113#ifdef CONFIG_OF
 114static const struct of_device_id tps6507x_of_match[] = {
 115        {.compatible = "ti,tps6507x", },
 116        {},
 117};
 118MODULE_DEVICE_TABLE(of, tps6507x_of_match);
 119#endif
 120
 121static struct i2c_driver tps6507x_i2c_driver = {
 122        .driver = {
 123                   .name = "tps6507x",
 124                   .of_match_table = of_match_ptr(tps6507x_of_match),
 125        },
 126        .probe = tps6507x_i2c_probe,
 127        .id_table = tps6507x_i2c_id,
 128};
 129
 130static int __init tps6507x_i2c_init(void)
 131{
 132        return i2c_add_driver(&tps6507x_i2c_driver);
 133}
 134/* init early so consumer devices can complete system boot */
 135subsys_initcall(tps6507x_i2c_init);
 136
 137static void __exit tps6507x_i2c_exit(void)
 138{
 139        i2c_del_driver(&tps6507x_i2c_driver);
 140}
 141module_exit(tps6507x_i2c_exit);
 142
 143MODULE_DESCRIPTION("TPS6507x chip family multi-function driver");
 144MODULE_LICENSE("GPL");
 145