/drivers/staging/iio/addac/adt7316-spi.c
C | 180 lines | 131 code | 33 blank | 16 comment | 7 complexity | 13484eec0955312ac08b585504574282 MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
1/*
2 * API bus driver for ADT7316/7/8 ADT7516/7/9 digital temperature
3 * sensor, ADC and DAC
4 *
5 * Copyright 2010 Analog Devices Inc.
6 *
7 * Licensed under the GPL-2 or later.
8 */
9
10#include <linux/device.h>
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/interrupt.h>
14#include <linux/spi/spi.h>
15
16#include "adt7316.h"
17
18#define ADT7316_SPI_MAX_FREQ_HZ 5000000
19#define ADT7316_SPI_CMD_READ 0x91
20#define ADT7316_SPI_CMD_WRITE 0x90
21
22/*
23 * adt7316 register access by SPI
24 */
25
26static int adt7316_spi_multi_read(void *client, u8 reg, u8 count, u8 *data)
27{
28 struct spi_device *spi_dev = client;
29 u8 cmd[2];
30 int ret = 0;
31
32 if (count > ADT7316_REG_MAX_ADDR)
33 count = ADT7316_REG_MAX_ADDR;
34
35 cmd[0] = ADT7316_SPI_CMD_WRITE;
36 cmd[1] = reg;
37
38 ret = spi_write(spi_dev, cmd, 2);
39 if (ret < 0) {
40 dev_err(&spi_dev->dev, "SPI fail to select reg\n");
41 return ret;
42 }
43
44 cmd[0] = ADT7316_SPI_CMD_READ;
45
46 ret = spi_write_then_read(spi_dev, cmd, 1, data, count);
47 if (ret < 0) {
48 dev_err(&spi_dev->dev, "SPI read data error\n");
49 return ret;
50 }
51
52 return 0;
53}
54
55static int adt7316_spi_multi_write(void *client, u8 reg, u8 count, u8 *data)
56{
57 struct spi_device *spi_dev = client;
58 u8 buf[ADT7316_REG_MAX_ADDR + 2];
59 int i, ret = 0;
60
61 if (count > ADT7316_REG_MAX_ADDR)
62 count = ADT7316_REG_MAX_ADDR;
63
64 buf[0] = ADT7316_SPI_CMD_WRITE;
65 buf[1] = reg;
66 for (i = 0; i < count; i++)
67 buf[i + 2] = data[i];
68
69 ret = spi_write(spi_dev, buf, count + 2);
70 if (ret < 0) {
71 dev_err(&spi_dev->dev, "SPI write error\n");
72 return ret;
73 }
74
75 return ret;
76}
77
78static int adt7316_spi_read(void *client, u8 reg, u8 *data)
79{
80 return adt7316_spi_multi_read(client, reg, 1, data);
81}
82
83static int adt7316_spi_write(void *client, u8 reg, u8 val)
84{
85 return adt7316_spi_multi_write(client, reg, 1, &val);
86}
87
88/*
89 * device probe and remove
90 */
91
92static int __devinit adt7316_spi_probe(struct spi_device *spi_dev)
93{
94 struct adt7316_bus bus = {
95 .client = spi_dev,
96 .irq = spi_dev->irq,
97 .irq_flags = IRQF_TRIGGER_LOW,
98 .read = adt7316_spi_read,
99 .write = adt7316_spi_write,
100 .multi_read = adt7316_spi_multi_read,
101 .multi_write = adt7316_spi_multi_write,
102 };
103
104 /* don't exceed max specified SPI CLK frequency */
105 if (spi_dev->max_speed_hz > ADT7316_SPI_MAX_FREQ_HZ) {
106 dev_err(&spi_dev->dev, "SPI CLK %d Hz?\n",
107 spi_dev->max_speed_hz);
108 return -EINVAL;
109 }
110
111 /* switch from default I2C protocol to SPI protocol */
112 adt7316_spi_write(spi_dev, 0, 0);
113 adt7316_spi_write(spi_dev, 0, 0);
114 adt7316_spi_write(spi_dev, 0, 0);
115
116 return adt7316_probe(&spi_dev->dev, &bus, spi_dev->modalias);
117}
118
119static int __devexit adt7316_spi_remove(struct spi_device *spi_dev)
120{
121 return adt7316_remove(&spi_dev->dev);
122}
123
124static const struct spi_device_id adt7316_spi_id[] = {
125 { "adt7316", 0 },
126 { "adt7317", 0 },
127 { "adt7318", 0 },
128 { "adt7516", 0 },
129 { "adt7517", 0 },
130 { "adt7519", 0 },
131 { }
132};
133
134MODULE_DEVICE_TABLE(spi, adt7316_spi_id);
135
136#ifdef CONFIG_PM
137static int adt7316_spi_suspend(struct spi_device *spi_dev, pm_message_t message)
138{
139 return adt7316_disable(&spi_dev->dev);
140}
141
142static int adt7316_spi_resume(struct spi_device *spi_dev)
143{
144 return adt7316_enable(&spi_dev->dev);
145}
146#else
147# define adt7316_spi_suspend NULL
148# define adt7316_spi_resume NULL
149#endif
150
151static struct spi_driver adt7316_driver = {
152 .driver = {
153 .name = "adt7316",
154 .bus = &spi_bus_type,
155 .owner = THIS_MODULE,
156 },
157 .probe = adt7316_spi_probe,
158 .remove = __devexit_p(adt7316_spi_remove),
159 .suspend = adt7316_spi_suspend,
160 .resume = adt7316_spi_resume,
161 .id_table = adt7316_spi_id,
162};
163
164static __init int adt7316_spi_init(void)
165{
166 return spi_register_driver(&adt7316_driver);
167}
168
169static __exit void adt7316_spi_exit(void)
170{
171 spi_unregister_driver(&adt7316_driver);
172}
173
174MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>");
175MODULE_DESCRIPTION("SPI bus driver for Analog Devices ADT7316/7/8 and"
176 "ADT7516/7/9 digital temperature sensor, ADC and DAC");
177MODULE_LICENSE("GPL v2");
178
179module_init(adt7316_spi_init);
180module_exit(adt7316_spi_exit);