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Michael Hennerich6c536e42010-05-24 14:33:14 -07001/*
2 * Driver for the Analog Devices digital potentiometers (SPI bus)
3 *
4 * Copyright (C) 2010 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
14static const struct ad_dpot_id ad_dpot_spi_devlist[] = {
15 {.name = "ad5160", .devid = AD5160_ID},
16 {.name = "ad5161", .devid = AD5161_ID},
17 {.name = "ad5162", .devid = AD5162_ID},
18 {.name = "ad5165", .devid = AD5165_ID},
19 {.name = "ad5200", .devid = AD5200_ID},
20 {.name = "ad5201", .devid = AD5201_ID},
21 {.name = "ad5203", .devid = AD5203_ID},
22 {.name = "ad5204", .devid = AD5204_ID},
23 {.name = "ad5206", .devid = AD5206_ID},
24 {.name = "ad5207", .devid = AD5207_ID},
25 {.name = "ad5231", .devid = AD5231_ID},
26 {.name = "ad5232", .devid = AD5232_ID},
27 {.name = "ad5233", .devid = AD5233_ID},
28 {.name = "ad5235", .devid = AD5235_ID},
29 {.name = "ad5260", .devid = AD5260_ID},
30 {.name = "ad5262", .devid = AD5262_ID},
31 {.name = "ad5263", .devid = AD5263_ID},
32 {.name = "ad5290", .devid = AD5290_ID},
33 {.name = "ad5291", .devid = AD5291_ID},
34 {.name = "ad5292", .devid = AD5292_ID},
35 {.name = "ad5293", .devid = AD5293_ID},
36 {.name = "ad7376", .devid = AD7376_ID},
37 {.name = "ad8400", .devid = AD8400_ID},
38 {.name = "ad8402", .devid = AD8402_ID},
39 {.name = "ad8403", .devid = AD8403_ID},
40 {.name = "adn2850", .devid = ADN2850_ID},
41 {}
42};
43
44/* ------------------------------------------------------------------------- */
45
46/* SPI bus functions */
47static int write8(void *client, u8 val)
48{
49 u8 data = val;
50 return spi_write(client, &data, 1);
51}
52
53static int write16(void *client, u8 reg, u8 val)
54{
55 u8 data[2] = {reg, val};
56 return spi_write(client, data, 1);
57}
58
59static int write24(void *client, u8 reg, u16 val)
60{
61 u8 data[3] = {reg, val >> 8, val};
62 return spi_write(client, data, 1);
63}
64
65static int read8(void *client)
66{
67 int ret;
68 u8 data;
69 ret = spi_read(client, &data, 1);
70 if (ret < 0)
71 return ret;
72
73 return data;
74}
75
76static int read16(void *client, u8 reg)
77{
78 int ret;
79 u8 buf_rx[2];
80
81 write16(client, reg, 0);
82 ret = spi_read(client, buf_rx, 2);
83 if (ret < 0)
84 return ret;
85
86 return (buf_rx[0] << 8) | buf_rx[1];
87}
88
89static int read24(void *client, u8 reg)
90{
91 int ret;
92 u8 buf_rx[3];
93
94 write24(client, reg, 0);
95 ret = spi_read(client, buf_rx, 3);
96 if (ret < 0)
97 return ret;
98
99 return (buf_rx[1] << 8) | buf_rx[2];
100}
101
102static const struct ad_dpot_bus_ops bops = {
103 .read_d8 = read8,
104 .read_r8d8 = read16,
105 .read_r8d16 = read24,
106 .write_d8 = write8,
107 .write_r8d8 = write16,
108 .write_r8d16 = write24,
109};
110
111static const struct ad_dpot_id *dpot_match_id(const struct ad_dpot_id *id,
112 char *name)
113{
114 while (id->name && id->name[0]) {
115 if (strcmp(name, id->name) == 0)
116 return id;
117 id++;
118 }
119 return NULL;
120}
121
122static int __devinit ad_dpot_spi_probe(struct spi_device *spi)
123{
124 char *name = spi->dev.platform_data;
125 const struct ad_dpot_id *dpot_id;
126
127 struct ad_dpot_bus_data bdata = {
128 .client = spi,
129 .bops = &bops,
130 };
131
132 dpot_id = dpot_match_id(ad_dpot_spi_devlist, name);
133
134 if (dpot_id == NULL) {
135 dev_err(&spi->dev, "%s not in supported device list", name);
136 return -ENODEV;
137 }
138
139 return ad_dpot_probe(&spi->dev, &bdata, dpot_id);
140}
141
142static int __devexit ad_dpot_spi_remove(struct spi_device *spi)
143{
144 return ad_dpot_remove(&spi->dev);
145}
146
147static struct spi_driver ad_dpot_spi_driver = {
148 .driver = {
149 .name = "ad_dpot",
150 .bus = &spi_bus_type,
151 .owner = THIS_MODULE,
152 },
153 .probe = ad_dpot_spi_probe,
154 .remove = __devexit_p(ad_dpot_spi_remove),
155};
156
157static int __init ad_dpot_spi_init(void)
158{
159 return spi_register_driver(&ad_dpot_spi_driver);
160}
161module_init(ad_dpot_spi_init);
162
163static void __exit ad_dpot_spi_exit(void)
164{
165 spi_unregister_driver(&ad_dpot_spi_driver);
166}
167module_exit(ad_dpot_spi_exit);
168
169MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
170MODULE_DESCRIPTION("digital potentiometer SPI bus driver");
171MODULE_LICENSE("GPL");
172MODULE_ALIAS("spi:ad_dpot");