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 void ad_dpot_spi_remove(struct spi_device *spi)
94 {
95 	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");
146