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 */
14static int write8(void *client, u8 val)
15{
16 u8 data = val;
17
18 return spi_write(spi: client, buf: &data, len: 1);
19}
20
21static int write16(void *client, u8 reg, u8 val)
22{
23 u8 data[2] = {reg, val};
24
25 return spi_write(spi: client, buf: data, len: 2);
26}
27
28static int write24(void *client, u8 reg, u16 val)
29{
30 u8 data[3] = {reg, val >> 8, val};
31
32 return spi_write(spi: client, buf: data, len: 3);
33}
34
35static int read8(void *client)
36{
37 int ret;
38 u8 data;
39
40 ret = spi_read(spi: client, buf: &data, len: 1);
41 if (ret < 0)
42 return ret;
43
44 return data;
45}
46
47static int read16(void *client, u8 reg)
48{
49 int ret;
50 u8 buf_rx[2];
51
52 write16(client, reg, val: 0);
53 ret = spi_read(spi: client, buf: buf_rx, len: 2);
54 if (ret < 0)
55 return ret;
56
57 return (buf_rx[0] << 8) | buf_rx[1];
58}
59
60static int read24(void *client, u8 reg)
61{
62 int ret;
63 u8 buf_rx[3];
64
65 write24(client, reg, val: 0);
66 ret = spi_read(spi: client, buf: buf_rx, len: 3);
67 if (ret < 0)
68 return ret;
69
70 return (buf_rx[1] << 8) | buf_rx[2];
71}
72
73static 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};
81static 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(dev: &spi->dev, bdata: &bdata,
89 devid: spi_get_device_id(sdev: spi)->driver_data,
90 name: spi_get_device_id(sdev: spi)->name);
91}
92
93static void ad_dpot_spi_remove(struct spi_device *spi)
94{
95 ad_dpot_remove(dev: &spi->dev);
96}
97
98static 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};
129MODULE_DEVICE_TABLE(spi, ad_dpot_spi_id);
130
131static 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
140module_spi_driver(ad_dpot_spi_driver);
141
142MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
143MODULE_DESCRIPTION("digital potentiometer SPI bus driver");
144MODULE_LICENSE("GPL");
145MODULE_ALIAS("spi:ad_dpot");
146

source code of linux/drivers/misc/ad525x_dpot-spi.c