xref: /openbmc/linux/drivers/iio/dac/ad5592r.c (revision fb574682)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * AD5592R Digital <-> Analog converters driver
4  *
5  * Copyright 2015-2016 Analog Devices Inc.
6  * Author: Paul Cercueil <paul.cercueil@analog.com>
7  */
8 
9 #include "ad5592r-base.h"
10 
11 #include <linux/bitops.h>
12 #include <linux/module.h>
13 #include <linux/of.h>
14 #include <linux/spi/spi.h>
15 #include <linux/acpi.h>
16 
17 #define AD5592R_GPIO_READBACK_EN	BIT(10)
18 #define AD5592R_LDAC_READBACK_EN	BIT(6)
19 
20 static 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 
34 static 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 
43 static 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 
71 static 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 
80 static 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 
101 static int ad5592r_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 
119 static 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 = ad5592r_gpio_read,
125 };
126 
127 static 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 
134 static int ad5592r_spi_remove(struct spi_device *spi)
135 {
136 	return ad5592r_remove(&spi->dev);
137 }
138 
139 static const struct spi_device_id ad5592r_spi_ids[] = {
140 	{ .name = "ad5592r", },
141 	{}
142 };
143 MODULE_DEVICE_TABLE(spi, ad5592r_spi_ids);
144 
145 static const struct of_device_id ad5592r_of_match[] = {
146 	{ .compatible = "adi,ad5592r", },
147 	{},
148 };
149 MODULE_DEVICE_TABLE(of, ad5592r_of_match);
150 
151 static const struct acpi_device_id ad5592r_acpi_match[] = {
152 	{"ADS5592", },
153 	{ },
154 };
155 MODULE_DEVICE_TABLE(acpi, ad5592r_acpi_match);
156 
157 static struct spi_driver ad5592r_spi_driver = {
158 	.driver = {
159 		.name = "ad5592r",
160 		.of_match_table = of_match_ptr(ad5592r_of_match),
161 		.acpi_match_table = ACPI_PTR(ad5592r_acpi_match),
162 	},
163 	.probe = ad5592r_spi_probe,
164 	.remove = ad5592r_spi_remove,
165 	.id_table = ad5592r_spi_ids,
166 };
167 module_spi_driver(ad5592r_spi_driver);
168 
169 MODULE_AUTHOR("Paul Cercueil <paul.cercueil@analog.com>");
170 MODULE_DESCRIPTION("Analog Devices AD5592R multi-channel converters");
171 MODULE_LICENSE("GPL v2");
172