drivers/misc/ad525x_dpot-spi.c

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