tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
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 {.name = "ad5270", .devid = AD5270_ID},
42 {.name = "ad5271", .devid = AD5271_ID},
43 {}
44};
45
46/* ------------------------------------------------------------------------- */
47
48/* SPI bus functions */
49static int write8(void *client, u8 val)
50{
51 u8 data = val;
52 return spi_write(client, &data, 1);
53}
54
55static int write16(void *client, u8 reg, u8 val)
56{
57 u8 data[2] = {reg, val};
58 return spi_write(client, data, 2);
59}
60
61static int write24(void *client, u8 reg, u16 val)
62{
63 u8 data[3] = {reg, val >> 8, val};
64 return spi_write(client, data, 3);
65}
66
67static int read8(void *client)
68{
69 int ret;
70 u8 data;
71 ret = spi_read(client, &data, 1);
72 if (ret < 0)
73 return ret;
74
75 return data;
76}
77
78static int read16(void *client, u8 reg)
79{
80 int ret;
81 u8 buf_rx[2];
82
83 write16(client, reg, 0);
84 ret = spi_read(client, buf_rx, 2);
85 if (ret < 0)
86 return ret;
87
88 return (buf_rx[0] << 8) | buf_rx[1];
89}
90
91static int read24(void *client, u8 reg)
92{
93 int ret;
94 u8 buf_rx[3];
95
96 write24(client, reg, 0);
97 ret = spi_read(client, buf_rx, 3);
98 if (ret < 0)
99 return ret;
100
101 return (buf_rx[1] << 8) | buf_rx[2];
102}
103
104static const struct ad_dpot_bus_ops bops = {
105 .read_d8 = read8,
106 .read_r8d8 = read16,
107 .read_r8d16 = read24,
108 .write_d8 = write8,
109 .write_r8d8 = write16,
110 .write_r8d16 = write24,
111};
112
113static const struct ad_dpot_id *dpot_match_id(const struct ad_dpot_id *id,
114 char *name)
115{
116 while (id->name && id->name[0]) {
117 if (strcmp(name, id->name) == 0)
118 return id;
119 id++;
120 }
121 return NULL;
122}
123
124static int __devinit ad_dpot_spi_probe(struct spi_device *spi)
125{
126 char *name = spi->dev.platform_data;
127 const struct ad_dpot_id *dpot_id;
128
129 struct ad_dpot_bus_data bdata = {
130 .client = spi,
131 .bops = &bops,
132 };
133
134 dpot_id = dpot_match_id(ad_dpot_spi_devlist, name);
135
136 if (dpot_id == NULL) {
137 dev_err(&spi->dev, "%s not in supported device list", name);
138 return -ENODEV;
139 }
140
141 return ad_dpot_probe(&spi->dev, &bdata, dpot_id);
142}
143
144static int __devexit ad_dpot_spi_remove(struct spi_device *spi)
145{
146 return ad_dpot_remove(&spi->dev);
147}
148
149static struct spi_driver ad_dpot_spi_driver = {
150 .driver = {
151 .name = "ad_dpot",
152 .bus = &spi_bus_type,
153 .owner = THIS_MODULE,
154 },
155 .probe = ad_dpot_spi_probe,
156 .remove = __devexit_p(ad_dpot_spi_remove),
157};
158
159static int __init ad_dpot_spi_init(void)
160{
161 return spi_register_driver(&ad_dpot_spi_driver);
162}
163module_init(ad_dpot_spi_init);
164
165static void __exit ad_dpot_spi_exit(void)
166{
167 spi_unregister_driver(&ad_dpot_spi_driver);
168}
169module_exit(ad_dpot_spi_exit);
170
171MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
172MODULE_DESCRIPTION("digital potentiometer SPI bus driver");
173MODULE_LICENSE("GPL");
174MODULE_ALIAS("spi:ad_dpot");