xref: /openbmc/linux/drivers/iio/dac/ad5592r.c (revision b737eecd)
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/mod_devicetable.h>
14 #include <linux/spi/spi.h>
15 
16 #define AD5592R_GPIO_READBACK_EN	BIT(10)
17 #define AD5592R_LDAC_READBACK_EN	BIT(6)
18 
19 static int ad5592r_spi_wnop_r16(struct ad5592r_state *st, __be16 *buf)
20 {
21 	struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
22 	struct spi_transfer t = {
23 			.tx_buf	= &st->spi_msg_nop,
24 			.rx_buf	= buf,
25 			.len = 2
26 		};
27 
28 	st->spi_msg_nop = 0; /* NOP */
29 
30 	return spi_sync_transfer(spi, &t, 1);
31 }
32 
33 static int ad5592r_write_dac(struct ad5592r_state *st, unsigned chan, u16 value)
34 {
35 	struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
36 
37 	st->spi_msg = cpu_to_be16(BIT(15) | (chan << 12) | value);
38 
39 	return spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
40 }
41 
42 static int ad5592r_read_adc(struct ad5592r_state *st, unsigned chan, u16 *value)
43 {
44 	struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
45 	int ret;
46 
47 	st->spi_msg = cpu_to_be16((AD5592R_REG_ADC_SEQ << 11) | BIT(chan));
48 
49 	ret = spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
50 	if (ret)
51 		return ret;
52 
53 	/*
54 	 * Invalid data:
55 	 * See Figure 40. Single-Channel ADC Conversion Sequence
56 	 */
57 	ret = ad5592r_spi_wnop_r16(st, &st->spi_msg);
58 	if (ret)
59 		return ret;
60 
61 	ret = ad5592r_spi_wnop_r16(st, &st->spi_msg);
62 	if (ret)
63 		return ret;
64 
65 	*value = be16_to_cpu(st->spi_msg);
66 
67 	return 0;
68 }
69 
70 static int ad5592r_reg_write(struct ad5592r_state *st, u8 reg, u16 value)
71 {
72 	struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
73 
74 	st->spi_msg = cpu_to_be16((reg << 11) | value);
75 
76 	return spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
77 }
78 
79 static int ad5592r_reg_read(struct ad5592r_state *st, u8 reg, u16 *value)
80 {
81 	struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
82 	int ret;
83 
84 	st->spi_msg = cpu_to_be16((AD5592R_REG_LDAC << 11) |
85 				   AD5592R_LDAC_READBACK_EN | (reg << 2));
86 
87 	ret = spi_write(spi, &st->spi_msg, sizeof(st->spi_msg));
88 	if (ret)
89 		return ret;
90 
91 	ret = ad5592r_spi_wnop_r16(st, &st->spi_msg);
92 	if (ret)
93 		return ret;
94 
95 	*value = be16_to_cpu(st->spi_msg);
96 
97 	return 0;
98 }
99 
100 static int ad5592r_gpio_read(struct ad5592r_state *st, u8 *value)
101 {
102 	int ret;
103 
104 	ret = ad5592r_reg_write(st, AD5592R_REG_GPIO_IN_EN,
105 				AD5592R_GPIO_READBACK_EN | st->gpio_in);
106 	if (ret)
107 		return ret;
108 
109 	ret = ad5592r_spi_wnop_r16(st, &st->spi_msg);
110 	if (ret)
111 		return ret;
112 
113 	*value = (u8) be16_to_cpu(st->spi_msg);
114 
115 	return 0;
116 }
117 
118 static const struct ad5592r_rw_ops ad5592r_rw_ops = {
119 	.write_dac = ad5592r_write_dac,
120 	.read_adc = ad5592r_read_adc,
121 	.reg_write = ad5592r_reg_write,
122 	.reg_read = ad5592r_reg_read,
123 	.gpio_read = ad5592r_gpio_read,
124 };
125 
126 static int ad5592r_spi_probe(struct spi_device *spi)
127 {
128 	const struct spi_device_id *id = spi_get_device_id(spi);
129 
130 	return ad5592r_probe(&spi->dev, id->name, &ad5592r_rw_ops);
131 }
132 
133 static int ad5592r_spi_remove(struct spi_device *spi)
134 {
135 	return ad5592r_remove(&spi->dev);
136 }
137 
138 static const struct spi_device_id ad5592r_spi_ids[] = {
139 	{ .name = "ad5592r", },
140 	{}
141 };
142 MODULE_DEVICE_TABLE(spi, ad5592r_spi_ids);
143 
144 static const struct of_device_id ad5592r_of_match[] = {
145 	{ .compatible = "adi,ad5592r", },
146 	{},
147 };
148 MODULE_DEVICE_TABLE(of, ad5592r_of_match);
149 
150 static const struct acpi_device_id ad5592r_acpi_match[] = {
151 	{"ADS5592", },
152 	{ },
153 };
154 MODULE_DEVICE_TABLE(acpi, ad5592r_acpi_match);
155 
156 static struct spi_driver ad5592r_spi_driver = {
157 	.driver = {
158 		.name = "ad5592r",
159 		.of_match_table = ad5592r_of_match,
160 		.acpi_match_table = ad5592r_acpi_match,
161 	},
162 	.probe = ad5592r_spi_probe,
163 	.remove = ad5592r_spi_remove,
164 	.id_table = ad5592r_spi_ids,
165 };
166 module_spi_driver(ad5592r_spi_driver);
167 
168 MODULE_AUTHOR("Paul Cercueil <paul.cercueil@analog.com>");
169 MODULE_DESCRIPTION("Analog Devices AD5592R multi-channel converters");
170 MODULE_LICENSE("GPL v2");
171