drivers/misc/ad525x_dpot-spi.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * Driver for the Analog Devices digital potentiometers (SPI bus)
0004  *
0005  * Copyright (C) 2010-2011 Michael Hennerich, Analog Devices Inc.
0006  */
0007
0008 #include <linux/spi/spi.h>
0009 #include <linux/module.h>
0010
0011 #include "ad525x_dpot.h"
0012
0013 /* SPI bus functions */
0014 static int write8(void *client, u8 val)
0015 {
0016     u8 data = val;
0017
0018     return spi_write(client, &data, 1);
0019 }
0020
0021 static int write16(void *client, u8 reg, u8 val)
0022 {
0023     u8 data[2] = {reg, val};
0024
0025     return spi_write(client, data, 2);
0026 }
0027
0028 static int write24(void *client, u8 reg, u16 val)
0029 {
0030     u8 data[3] = {reg, val >> 8, val};
0031
0032     return spi_write(client, data, 3);
0033 }
0034
0035 static int read8(void *client)
0036 {
0037     int ret;
0038     u8 data;
0039
0040     ret = spi_read(client, &data, 1);
0041     if (ret < 0)
0042         return ret;
0043
0044     return data;
0045 }
0046
0047 static int read16(void *client, u8 reg)
0048 {
0049     int ret;
0050     u8 buf_rx[2];
0051
0052     write16(client, reg, 0);
0053     ret = spi_read(client, buf_rx, 2);
0054     if (ret < 0)
0055         return ret;
0056
0057     return (buf_rx[0] << 8) |  buf_rx[1];
0058 }
0059
0060 static int read24(void *client, u8 reg)
0061 {
0062     int ret;
0063     u8 buf_rx[3];
0064
0065     write24(client, reg, 0);
0066     ret = spi_read(client, buf_rx, 3);
0067     if (ret < 0)
0068         return ret;
0069
0070     return (buf_rx[1] << 8) |  buf_rx[2];
0071 }
0072
0073 static const struct ad_dpot_bus_ops bops = {
0074     .read_d8    = read8,
0075     .read_r8d8  = read16,
0076     .read_r8d16 = read24,
0077     .write_d8   = write8,
0078     .write_r8d8 = write16,
0079     .write_r8d16    = write24,
0080 };
0081 static int ad_dpot_spi_probe(struct spi_device *spi)
0082 {
0083     struct ad_dpot_bus_data bdata = {
0084         .client = spi,
0085         .bops = &bops,
0086     };
0087
0088     return ad_dpot_probe(&spi->dev, &bdata,
0089                  spi_get_device_id(spi)->driver_data,
0090                  spi_get_device_id(spi)->name);
0091 }
0092
0093 static void ad_dpot_spi_remove(struct spi_device *spi)
0094 {
0095     ad_dpot_remove(&spi->dev);
0096 }
0097
0098 static const struct spi_device_id ad_dpot_spi_id[] = {
0099     {"ad5160", AD5160_ID},
0100     {"ad5161", AD5161_ID},
0101     {"ad5162", AD5162_ID},
0102     {"ad5165", AD5165_ID},
0103     {"ad5200", AD5200_ID},
0104     {"ad5201", AD5201_ID},
0105     {"ad5203", AD5203_ID},
0106     {"ad5204", AD5204_ID},
0107     {"ad5206", AD5206_ID},
0108     {"ad5207", AD5207_ID},
0109     {"ad5231", AD5231_ID},
0110     {"ad5232", AD5232_ID},
0111     {"ad5233", AD5233_ID},
0112     {"ad5235", AD5235_ID},
0113     {"ad5260", AD5260_ID},
0114     {"ad5262", AD5262_ID},
0115     {"ad5263", AD5263_ID},
0116     {"ad5290", AD5290_ID},
0117     {"ad5291", AD5291_ID},
0118     {"ad5292", AD5292_ID},
0119     {"ad5293", AD5293_ID},
0120     {"ad7376", AD7376_ID},
0121     {"ad8400", AD8400_ID},
0122     {"ad8402", AD8402_ID},
0123     {"ad8403", AD8403_ID},
0124     {"adn2850", ADN2850_ID},
0125     {"ad5270", AD5270_ID},
0126     {"ad5271", AD5271_ID},
0127     {}
0128 };
0129 MODULE_DEVICE_TABLE(spi, ad_dpot_spi_id);
0130
0131 static struct spi_driver ad_dpot_spi_driver = {
0132     .driver = {
0133         .name   = "ad_dpot",
0134     },
0135     .probe      = ad_dpot_spi_probe,
0136     .remove     = ad_dpot_spi_remove,
0137     .id_table   = ad_dpot_spi_id,
0138 };
0139
0140 module_spi_driver(ad_dpot_spi_driver);
0141
0142 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
0143 MODULE_DESCRIPTION("digital potentiometer SPI bus driver");
0144 MODULE_LICENSE("GPL");
0145 MODULE_ALIAS("spi:ad_dpot");