tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * AD5592R Digital <-> Analog converters driver
3 *
4 * Copyright 2015-2016 Analog Devices Inc.
5 * Author: Paul Cercueil <paul.cercueil@analog.com>
6 *
7 * Licensed under the GPL-2.
8 */
9
10#include "ad5592r-base.h"
11
12#include <linux/bitops.h>
13#include <linux/module.h>
14#include <linux/of.h>
15#include <linux/spi/spi.h>
16
17#define AD5592R_GPIO_READBACK_EN BIT(10)
18#define AD5592R_LDAC_READBACK_EN BIT(6)
19
20static int ad5592r_spi_wnop_r16(struct ad5592r_state *st, __be16 *buf)
21{
22 struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
23 struct spi_transfer t = {
24 .tx_buf = &st->spi_msg_nop,
25 .rx_buf = buf,
26 .len = 2
27 };
28
29 st->spi_msg_nop = 0; /* NOP */
30
31 return spi_sync_transfer(spi, &t, 1);
32}
33
34static int ad5592r_write_dac(struct ad5592r_state *st, unsigned chan, u16 value)
35{
36 struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
37
38 st->spi_msg = cpu_to_be16(BIT(15) | (chan << 12) | value);
39
40 return spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
41}
42
43static int ad5592r_read_adc(struct ad5592r_state *st, unsigned chan, u16 *value)
44{
45 struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
46 int ret;
47
48 st->spi_msg = cpu_to_be16((AD5592R_REG_ADC_SEQ << 11) | BIT(chan));
49
50 ret = spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
51 if (ret)
52 return ret;
53
54 /*
55 * Invalid data:
56 * See Figure 40. Single-Channel ADC Conversion Sequence
57 */
58 ret = ad5592r_spi_wnop_r16(st, &st->spi_msg);
59 if (ret)
60 return ret;
61
62 ret = ad5592r_spi_wnop_r16(st, &st->spi_msg);
63 if (ret)
64 return ret;
65
66 *value = be16_to_cpu(st->spi_msg);
67
68 return 0;
69}
70
71static int ad5592r_reg_write(struct ad5592r_state *st, u8 reg, u16 value)
72{
73 struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
74
75 st->spi_msg = cpu_to_be16((reg << 11) | value);
76
77 return spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
78}
79
80static int ad5592r_reg_read(struct ad5592r_state *st, u8 reg, u16 *value)
81{
82 struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
83 int ret;
84
85 st->spi_msg = cpu_to_be16((AD5592R_REG_LDAC << 11) |
86 AD5592R_LDAC_READBACK_EN | (reg << 2));
87
88 ret = spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
89 if (ret)
90 return ret;
91
92 ret = ad5592r_spi_wnop_r16(st, &st->spi_msg);
93 if (ret)
94 return ret;
95
96 *value = be16_to_cpu(st->spi_msg);
97
98 return 0;
99}
100
101static int ad5593r_gpio_read(struct ad5592r_state *st, u8 *value)
102{
103 int ret;
104
105 ret = ad5592r_reg_write(st, AD5592R_REG_GPIO_IN_EN,
106 AD5592R_GPIO_READBACK_EN | st->gpio_in);
107 if (ret)
108 return ret;
109
110 ret = ad5592r_spi_wnop_r16(st, &st->spi_msg);
111 if (ret)
112 return ret;
113
114 *value = (u8) be16_to_cpu(st->spi_msg);
115
116 return 0;
117}
118
119static const struct ad5592r_rw_ops ad5592r_rw_ops = {
120 .write_dac = ad5592r_write_dac,
121 .read_adc = ad5592r_read_adc,
122 .reg_write = ad5592r_reg_write,
123 .reg_read = ad5592r_reg_read,
124 .gpio_read = ad5593r_gpio_read,
125};
126
127static int ad5592r_spi_probe(struct spi_device *spi)
128{
129 const struct spi_device_id *id = spi_get_device_id(spi);
130
131 return ad5592r_probe(&spi->dev, id->name, &ad5592r_rw_ops);
132}
133
134static int ad5592r_spi_remove(struct spi_device *spi)
135{
136 return ad5592r_remove(&spi->dev);
137}
138
139static const struct spi_device_id ad5592r_spi_ids[] = {
140 { .name = "ad5592r", },
141 {}
142};
143MODULE_DEVICE_TABLE(spi, ad5592r_spi_ids);
144
145static const struct of_device_id ad5592r_of_match[] = {
146 { .compatible = "adi,ad5592r", },
147 {},
148};
149MODULE_DEVICE_TABLE(of, ad5592r_of_match);
150
151static struct spi_driver ad5592r_spi_driver = {
152 .driver = {
153 .name = "ad5592r",
154 .of_match_table = of_match_ptr(ad5592r_of_match),
155 },
156 .probe = ad5592r_spi_probe,
157 .remove = ad5592r_spi_remove,
158 .id_table = ad5592r_spi_ids,
159};
160module_spi_driver(ad5592r_spi_driver);
161
162MODULE_AUTHOR("Paul Cercueil <paul.cercueil@analog.com>");
163MODULE_DESCRIPTION("Analog Devices AD5592R multi-channel converters");
164MODULE_LICENSE("GPL v2");