drivers/misc/ad525x_dpot-spi.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Driver for the Analog Devices digital potentiometers (SPI bus)
   4  *
   5  * Copyright (C) 2010-2011 Michael Hennerich, Analog Devices Inc.
   6  */
   7
   8 #include <linux/spi/spi.h>
   9 #include <linux/module.h>
  10
  11 #include "ad525x_dpot.h"
  12
  13 /* SPI bus functions */
  14 static int write8(void *client, u8 val)
  15 {
  16         u8 data = val;
  17
  18         return spi_write(client, &data, 1);
  19 }
  20
  21 static int write16(void *client, u8 reg, u8 val)
  22 {
  23         u8 data[2] = {reg, val};
  24
  25         return spi_write(client, data, 2);
  26 }
  27
  28 static int write24(void *client, u8 reg, u16 val)
  29 {
  30         u8 data[3] = {reg, val >> 8, val};
  31
  32         return spi_write(client, data, 3);
  33 }
  34
  35 static int read8(void *client)
  36 {
  37         int ret;
  38         u8 data;
  39
  40         ret = spi_read(client, &data, 1);
  41         if (ret < 0)
  42                 return ret;
  43
  44         return data;
  45 }
  46
  47 static int read16(void *client, u8 reg)
  48 {
  49         int ret;
  50         u8 buf_rx[2];
  51
  52         write16(client, reg, 0);
  53         ret = spi_read(client, buf_rx, 2);
  54         if (ret < 0)
  55                 return ret;
  56
  57         return (buf_rx[0] << 8) |  buf_rx[1];
  58 }
  59
  60 static int read24(void *client, u8 reg)
  61 {
  62         int ret;
  63         u8 buf_rx[3];
  64
  65         write24(client, reg, 0);
  66         ret = spi_read(client, buf_rx, 3);
  67         if (ret < 0)
  68                 return ret;
  69
  70         return (buf_rx[1] << 8) |  buf_rx[2];
  71 }
  72
  73 static const struct ad_dpot_bus_ops bops = {
  74         .read_d8        = read8,
  75         .read_r8d8      = read16,
  76         .read_r8d16     = read24,
  77         .write_d8       = write8,
  78         .write_r8d8     = write16,
  79         .write_r8d16    = write24,
  80 };
  81 static int ad_dpot_spi_probe(struct spi_device *spi)
  82 {
  83         struct ad_dpot_bus_data bdata = {
  84                 .client = spi,
  85                 .bops = &bops,
  86         };
  87
  88         return ad_dpot_probe(&spi->dev, &bdata,
  89                              spi_get_device_id(spi)->driver_data,
  90                              spi_get_device_id(spi)->name);
  91 }
  92
  93 static int ad_dpot_spi_remove(struct spi_device *spi)
  94 {
  95         return ad_dpot_remove(&spi->dev);
  96 }
  97
  98 static const struct spi_device_id ad_dpot_spi_id[] = {
  99         {"ad5160", AD5160_ID},
 100         {"ad5161", AD5161_ID},
 101         {"ad5162", AD5162_ID},
 102         {"ad5165", AD5165_ID},
 103         {"ad5200", AD5200_ID},
 104         {"ad5201", AD5201_ID},
 105         {"ad5203", AD5203_ID},
 106         {"ad5204", AD5204_ID},
 107         {"ad5206", AD5206_ID},
 108         {"ad5207", AD5207_ID},
 109         {"ad5231", AD5231_ID},
 110         {"ad5232", AD5232_ID},
 111         {"ad5233", AD5233_ID},
 112         {"ad5235", AD5235_ID},
 113         {"ad5260", AD5260_ID},
 114         {"ad5262", AD5262_ID},
 115         {"ad5263", AD5263_ID},
 116         {"ad5290", AD5290_ID},
 117         {"ad5291", AD5291_ID},
 118         {"ad5292", AD5292_ID},
 119         {"ad5293", AD5293_ID},
 120         {"ad7376", AD7376_ID},
 121         {"ad8400", AD8400_ID},
 122         {"ad8402", AD8402_ID},
 123         {"ad8403", AD8403_ID},
 124         {"adn2850", ADN2850_ID},
 125         {"ad5270", AD5270_ID},
 126         {"ad5271", AD5271_ID},
 127         {}
 128 };
 129 MODULE_DEVICE_TABLE(spi, ad_dpot_spi_id);
 130
 131 static struct spi_driver ad_dpot_spi_driver = {
 132         .driver = {
 133                 .name   = "ad_dpot",
 134         },
 135         .probe          = ad_dpot_spi_probe,
 136         .remove         = ad_dpot_spi_remove,
 137         .id_table       = ad_dpot_spi_id,
 138 };
 139
 140 module_spi_driver(ad_dpot_spi_driver);
 141
 142 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
 143 MODULE_DESCRIPTION("digital potentiometer SPI bus driver");
 144 MODULE_LICENSE("GPL");
 145 MODULE_ALIAS("spi:ad_dpot");