1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Analog Devices AD7091R8 12-bit SAR ADC driver
4 *
5 * Copyright 2023 Analog Devices Inc.
6 */
7
8#include <linux/bitfield.h>
9#include <linux/iio/iio.h>
10#include <linux/module.h>
11#include <linux/regmap.h>
12#include <linux/gpio/consumer.h>
13#include <linux/spi/spi.h>
14
15#include "ad7091r-base.h"
16
17#define AD7091R8_REG_ADDR_MSK				GENMASK(15, 11)
18#define AD7091R8_RD_WR_FLAG_MSK				BIT(10)
19#define AD7091R8_REG_DATA_MSK				GENMASK(9, 0)
20
21#define AD7091R_SPI_REGMAP_CONFIG(n) {					\
22	.reg_bits = 8,							\
23	.val_bits = 16,							\
24	.volatile_reg = ad7091r_volatile_reg,				\
25	.writeable_reg = ad7091r_writeable_reg,				\
26	.max_register = AD7091R_REG_CH_HYSTERESIS(n),			\
27}
28
29static int ad7091r8_set_mode(struct ad7091r_state *st, enum ad7091r_mode mode)
30{
31	/* AD7091R-2/-4/-8 don't set sample/command/autocycle mode in conf reg */
32	st->mode = mode;
33	return 0;
34}
35
36static unsigned int ad7091r8_reg_result_chan_id(unsigned int val)
37{
38	return AD7091R8_REG_RESULT_CH_ID(val);
39}
40
41#define AD7091R_SPI_CHIP_INFO(_n, _name) {				\
42	.name = _name,							\
43	.channels = ad7091r##_n##_channels,				\
44	.num_channels = ARRAY_SIZE(ad7091r##_n##_channels),		\
45	.vref_mV = 2500,						\
46	.reg_result_chan_id = &ad7091r8_reg_result_chan_id,	\
47	.set_mode = &ad7091r8_set_mode,				\
48}
49
50#define AD7091R_SPI_CHIP_INFO_IRQ(_n, _name) {				\
51	.name = _name,							\
52	.channels = ad7091r##_n##_channels_irq,				\
53	.num_channels = ARRAY_SIZE(ad7091r##_n##_channels_irq),		\
54	.vref_mV = 2500,						\
55	.reg_result_chan_id = &ad7091r8_reg_result_chan_id,	\
56	.set_mode = &ad7091r8_set_mode,				\
57}
58
59enum ad7091r8_info_ids {
60	AD7091R2_INFO,
61	AD7091R4_INFO,
62	AD7091R4_INFO_IRQ,
63	AD7091R8_INFO,
64	AD7091R8_INFO_IRQ,
65};
66
67static const struct iio_chan_spec ad7091r2_channels[] = {
68	AD7091R_CHANNEL(0, 12, NULL, 0),
69	AD7091R_CHANNEL(1, 12, NULL, 0),
70};
71
72static const struct iio_chan_spec ad7091r4_channels[] = {
73	AD7091R_CHANNEL(0, 12, NULL, 0),
74	AD7091R_CHANNEL(1, 12, NULL, 0),
75	AD7091R_CHANNEL(2, 12, NULL, 0),
76	AD7091R_CHANNEL(3, 12, NULL, 0),
77};
78
79static const struct iio_chan_spec ad7091r4_channels_irq[] = {
80	AD7091R_CHANNEL(0, 12, ad7091r_events, ARRAY_SIZE(ad7091r_events)),
81	AD7091R_CHANNEL(1, 12, ad7091r_events, ARRAY_SIZE(ad7091r_events)),
82	AD7091R_CHANNEL(2, 12, ad7091r_events, ARRAY_SIZE(ad7091r_events)),
83	AD7091R_CHANNEL(3, 12, ad7091r_events, ARRAY_SIZE(ad7091r_events)),
84};
85
86static const struct iio_chan_spec ad7091r8_channels[] = {
87	AD7091R_CHANNEL(0, 12, NULL, 0),
88	AD7091R_CHANNEL(1, 12, NULL, 0),
89	AD7091R_CHANNEL(2, 12, NULL, 0),
90	AD7091R_CHANNEL(3, 12, NULL, 0),
91	AD7091R_CHANNEL(4, 12, NULL, 0),
92	AD7091R_CHANNEL(5, 12, NULL, 0),
93	AD7091R_CHANNEL(6, 12, NULL, 0),
94	AD7091R_CHANNEL(7, 12, NULL, 0),
95};
96
97static const struct iio_chan_spec ad7091r8_channels_irq[] = {
98	AD7091R_CHANNEL(0, 12, ad7091r_events, ARRAY_SIZE(ad7091r_events)),
99	AD7091R_CHANNEL(1, 12, ad7091r_events, ARRAY_SIZE(ad7091r_events)),
100	AD7091R_CHANNEL(2, 12, ad7091r_events, ARRAY_SIZE(ad7091r_events)),
101	AD7091R_CHANNEL(3, 12, ad7091r_events, ARRAY_SIZE(ad7091r_events)),
102	AD7091R_CHANNEL(4, 12, ad7091r_events, ARRAY_SIZE(ad7091r_events)),
103	AD7091R_CHANNEL(5, 12, ad7091r_events, ARRAY_SIZE(ad7091r_events)),
104	AD7091R_CHANNEL(6, 12, ad7091r_events, ARRAY_SIZE(ad7091r_events)),
105	AD7091R_CHANNEL(7, 12, ad7091r_events, ARRAY_SIZE(ad7091r_events)),
106};
107
108static void ad7091r_pulse_convst(struct ad7091r_state *st)
109{
110	gpiod_set_value_cansleep(st->convst_gpio, 1);
111	gpiod_set_value_cansleep(st->convst_gpio, 0);
112}
113
114static int ad7091r_regmap_bus_reg_read(void *context, unsigned int reg,
115				       unsigned int *val)
116{
117	struct ad7091r_state *st = context;
118	struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
119	int ret;
120
121	struct spi_transfer t[] = {
122		{
123			.tx_buf = &st->tx_buf,
124			.len = 2,
125			.cs_change = 1,
126		}, {
127			.rx_buf = &st->rx_buf,
128			.len = 2,
129		}
130	};
131
132	if (reg == AD7091R_REG_RESULT)
133		ad7091r_pulse_convst(st);
134
135	st->tx_buf = cpu_to_be16(reg << 11);
136
137	ret = spi_sync_transfer(spi, t, ARRAY_SIZE(t));
138	if (ret < 0)
139		return ret;
140
141	*val = be16_to_cpu(st->rx_buf);
142	return 0;
143}
144
145static int ad7091r_regmap_bus_reg_write(void *context, unsigned int reg,
146					unsigned int val)
147{
148	struct ad7091r_state *st = context;
149	struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
150
151	/*
152	 * AD7091R-2/-4/-8 protocol (datasheet page 31) is to do a single SPI
153	 * transfer with reg address set in bits B15:B11 and value set in B9:B0.
154	 */
155	st->tx_buf = cpu_to_be16(FIELD_PREP(AD7091R8_REG_DATA_MSK, val) |
156				 FIELD_PREP(AD7091R8_RD_WR_FLAG_MSK, 1) |
157				 FIELD_PREP(AD7091R8_REG_ADDR_MSK, reg));
158
159	return spi_write(spi, &st->tx_buf, 2);
160}
161
162static struct regmap_bus ad7091r8_regmap_bus = {
163	.reg_read = ad7091r_regmap_bus_reg_read,
164	.reg_write = ad7091r_regmap_bus_reg_write,
165	.reg_format_endian_default = REGMAP_ENDIAN_BIG,
166	.val_format_endian_default = REGMAP_ENDIAN_BIG,
167};
168
169static const struct ad7091r_chip_info ad7091r8_infos[] = {
170	[AD7091R2_INFO] = AD7091R_SPI_CHIP_INFO(2, "ad7091r-2"),
171	[AD7091R4_INFO] = AD7091R_SPI_CHIP_INFO(4, "ad7091r-4"),
172	[AD7091R4_INFO_IRQ] = AD7091R_SPI_CHIP_INFO_IRQ(4, "ad7091r-4"),
173	[AD7091R8_INFO] = AD7091R_SPI_CHIP_INFO(8, "ad7091r-8"),
174	[AD7091R8_INFO_IRQ] = AD7091R_SPI_CHIP_INFO_IRQ(8, "ad7091r-8")
175};
176
177static const struct regmap_config ad7091r2_reg_conf = AD7091R_SPI_REGMAP_CONFIG(2);
178static const struct regmap_config ad7091r4_reg_conf = AD7091R_SPI_REGMAP_CONFIG(4);
179static const struct regmap_config ad7091r8_reg_conf = AD7091R_SPI_REGMAP_CONFIG(8);
180
181static void ad7091r8_regmap_init(struct ad7091r_state *st,
182				 const struct regmap_config *regmap_conf)
183{
184	st->map = devm_regmap_init(st->dev, &ad7091r8_regmap_bus, st,
185				   regmap_conf);
186}
187
188static int ad7091r8_gpio_setup(struct ad7091r_state *st)
189{
190	st->convst_gpio = devm_gpiod_get(st->dev, "convst", GPIOD_OUT_LOW);
191	if (IS_ERR(st->convst_gpio))
192		return dev_err_probe(st->dev, PTR_ERR(st->convst_gpio),
193				     "Error getting convst GPIO\n");
194
195	st->reset_gpio = devm_gpiod_get_optional(st->dev, "reset",
196						 GPIOD_OUT_HIGH);
197	if (IS_ERR(st->reset_gpio))
198		return dev_err_probe(st->dev, PTR_ERR(st->reset_gpio),
199				     "Error on requesting reset GPIO\n");
200
201	if (st->reset_gpio) {
202		fsleep(20);
203		gpiod_set_value_cansleep(st->reset_gpio, 0);
204	}
205
206	return 0;
207}
208
209static struct ad7091r_init_info ad7091r2_init_info = {
210	.info_no_irq = &ad7091r8_infos[AD7091R2_INFO],
211	.regmap_config = &ad7091r2_reg_conf,
212	.init_adc_regmap = &ad7091r8_regmap_init,
213	.setup = &ad7091r8_gpio_setup
214};
215
216static struct ad7091r_init_info ad7091r4_init_info = {
217	.info_no_irq = &ad7091r8_infos[AD7091R4_INFO],
218	.info_irq = &ad7091r8_infos[AD7091R4_INFO_IRQ],
219	.regmap_config = &ad7091r4_reg_conf,
220	.init_adc_regmap = &ad7091r8_regmap_init,
221	.setup = &ad7091r8_gpio_setup
222};
223
224static struct ad7091r_init_info ad7091r8_init_info = {
225	.info_no_irq = &ad7091r8_infos[AD7091R8_INFO],
226	.info_irq = &ad7091r8_infos[AD7091R8_INFO_IRQ],
227	.regmap_config = &ad7091r8_reg_conf,
228	.init_adc_regmap = &ad7091r8_regmap_init,
229	.setup = &ad7091r8_gpio_setup
230};
231
232static int ad7091r8_spi_probe(struct spi_device *spi)
233{
234	const struct ad7091r_init_info *init_info;
235
236	init_info = spi_get_device_match_data(spi);
237	if (!init_info)
238		return -EINVAL;
239
240	return ad7091r_probe(&spi->dev, init_info, spi->irq);
241}
242
243static const struct of_device_id ad7091r8_of_match[] = {
244	{ .compatible = "adi,ad7091r2", .data = &ad7091r2_init_info },
245	{ .compatible = "adi,ad7091r4", .data = &ad7091r4_init_info },
246	{ .compatible = "adi,ad7091r8", .data = &ad7091r8_init_info },
247	{ }
248};
249MODULE_DEVICE_TABLE(of, ad7091r8_of_match);
250
251static const struct spi_device_id ad7091r8_spi_id[] = {
252	{ "ad7091r2", (kernel_ulong_t)&ad7091r2_init_info },
253	{ "ad7091r4", (kernel_ulong_t)&ad7091r4_init_info },
254	{ "ad7091r8", (kernel_ulong_t)&ad7091r8_init_info },
255	{ }
256};
257MODULE_DEVICE_TABLE(spi, ad7091r8_spi_id);
258
259static struct spi_driver ad7091r8_driver = {
260	.driver = {
261		.name = "ad7091r8",
262		.of_match_table = ad7091r8_of_match,
263	},
264	.probe = ad7091r8_spi_probe,
265	.id_table = ad7091r8_spi_id,
266};
267module_spi_driver(ad7091r8_driver);
268
269MODULE_AUTHOR("Marcelo Schmitt <marcelo.schmitt@analog.com>");
270MODULE_DESCRIPTION("Analog Devices AD7091R8 ADC driver");
271MODULE_LICENSE("GPL");
272MODULE_IMPORT_NS(IIO_AD7091R);
273