LXR linux/drivers/misc/ad525x

   1/*
   2 * Driver for the Analog Devices digital potentiometers (SPI bus)
   3 *
   4 * Copyright (C) 2010-2011 Michael Hennerich, Analog Devices Inc.
   5 *
   6 * Licensed under the GPL-2 or later.
   7 */
   8
   9#include <linux/spi/spi.h>
  10#include <linux/module.h>
  11
  12#include "ad525x_dpot.h"
  13
  14/* SPI bus functions */
  15static int write8(void *client, u8 val)
  16{
  17        u8 data = val;
  18        return spi_write(client, &data, 1);
  19}
  20
  21static int write16(void *client, u8 reg, u8 val)
  22{
  23        u8 data[2] = {reg, val};
  24        return spi_write(client, data, 2);
  25}
  26
  27static int write24(void *client, u8 reg, u16 val)
  28{
  29        u8 data[3] = {reg, val >> 8, val};
  30        return spi_write(client, data, 3);
  31}
  32
  33static int read8(void *client)
  34{
  35        int ret;
  36        u8 data;
  37        ret = spi_read(client, &data, 1);
  38        if (ret < 0)
  39                return ret;
  40
  41        return data;
  42}
  43
  44static int read16(void *client, u8 reg)
  45{
  46        int ret;
  47        u8 buf_rx[2];
  48
  49        write16(client, reg, 0);
  50        ret = spi_read(client, buf_rx, 2);
  51        if (ret < 0)
  52                return ret;
  53
  54        return (buf_rx[0] << 8) |  buf_rx[1];
  55}
  56
  57static int read24(void *client, u8 reg)
  58{
  59        int ret;
  60        u8 buf_rx[3];
  61
  62        write24(client, reg, 0);
  63        ret = spi_read(client, buf_rx, 3);
  64        if (ret < 0)
  65                return ret;
  66
  67        return (buf_rx[1] << 8) |  buf_rx[2];
  68}
  69
  70static const struct ad_dpot_bus_ops bops = {
  71        .read_d8        = read8,
  72        .read_r8d8      = read16,
  73        .read_r8d16     = read24,
  74        .write_d8       = write8,
  75        .write_r8d8     = write16,
  76        .write_r8d16    = write24,
  77};
  78static int __devinit ad_dpot_spi_probe(struct spi_device *spi)
  79{
  80        struct ad_dpot_bus_data bdata = {
  81                .client = spi,
  82                .bops = &bops,
  83        };
  84
  85        return ad_dpot_probe(&spi->dev, &bdata,
  86                             spi_get_device_id(spi)->driver_data,
  87                             spi_get_device_id(spi)->name);
  88}
  89
  90static int __devexit ad_dpot_spi_remove(struct spi_device *spi)
  91{
  92        return ad_dpot_remove(&spi->dev);
  93}
  94
  95static const struct spi_device_id ad_dpot_spi_id[] = {
  96        {"ad5160", AD5160_ID},
  97        {"ad5161", AD5161_ID},
  98        {"ad5162", AD5162_ID},
  99        {"ad5165", AD5165_ID},
 100        {"ad5200", AD5200_ID},
 101        {"ad5201", AD5201_ID},
 102        {"ad5203", AD5203_ID},
 103        {"ad5204", AD5204_ID},
 104        {"ad5206", AD5206_ID},
 105        {"ad5207", AD5207_ID},
 106        {"ad5231", AD5231_ID},
 107        {"ad5232", AD5232_ID},
 108        {"ad5233", AD5233_ID},
 109        {"ad5235", AD5235_ID},
 110        {"ad5260", AD5260_ID},
 111        {"ad5262", AD5262_ID},
 112        {"ad5263", AD5263_ID},
 113        {"ad5290", AD5290_ID},
 114        {"ad5291", AD5291_ID},
 115        {"ad5292", AD5292_ID},
 116        {"ad5293", AD5293_ID},
 117        {"ad7376", AD7376_ID},
 118        {"ad8400", AD8400_ID},
 119        {"ad8402", AD8402_ID},
 120        {"ad8403", AD8403_ID},
 121        {"adn2850", ADN2850_ID},
 122        {"ad5270", AD5270_ID},
 123        {"ad5271", AD5271_ID},
 124        {}
 125};
 126MODULE_DEVICE_TABLE(spi, ad_dpot_spi_id);
 127
 128static struct spi_driver ad_dpot_spi_driver = {
 129        .driver = {
 130                .name   = "ad_dpot",
 131                .owner  = THIS_MODULE,
 132        },
 133        .probe          = ad_dpot_spi_probe,
 134        .remove         = __devexit_p(ad_dpot_spi_remove),
 135        .id_table       = ad_dpot_spi_id,
 136};
 137
 138static int __init ad_dpot_spi_init(void)
 139{
 140        return spi_register_driver(&ad_dpot_spi_driver);
 141}
 142module_init(ad_dpot_spi_init);
 143
 144static void __exit ad_dpot_spi_exit(void)
 145{
 146        spi_unregister_driver(&ad_dpot_spi_driver);
 147}
 148module_exit(ad_dpot_spi_exit);
 149
 150MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 151MODULE_DESCRIPTION("digital potentiometer SPI bus driver");
 152MODULE_LICENSE("GPL");
 153MODULE_ALIAS("spi:ad_dpot");
 154