xref: /openbmc/linux/drivers/iio/dac/ad5624r_spi.c (revision 7effbd18)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * AD5624R, AD5644R, AD5664R Digital to analog convertors spi driver
4  *
5  * Copyright 2010-2011 Analog Devices Inc.
6  */
7 
8 #include <linux/interrupt.h>
9 #include <linux/fs.h>
10 #include <linux/device.h>
11 #include <linux/kernel.h>
12 #include <linux/spi/spi.h>
13 #include <linux/slab.h>
14 #include <linux/sysfs.h>
15 #include <linux/regulator/consumer.h>
16 #include <linux/module.h>
17 
18 #include <linux/iio/iio.h>
19 #include <linux/iio/sysfs.h>
20 
21 #include <asm/unaligned.h>
22 
23 #include "ad5624r.h"
24 
25 static int ad5624r_spi_write(struct spi_device *spi,
26 			     u8 cmd, u8 addr, u16 val, u8 shift)
27 {
28 	u32 data;
29 	u8 msg[3];
30 
31 	/*
32 	 * The input shift register is 24 bits wide. The first two bits are
33 	 * don't care bits. The next three are the command bits, C2 to C0,
34 	 * followed by the 3-bit DAC address, A2 to A0, and then the
35 	 * 16-, 14-, 12-bit data-word. The data-word comprises the 16-,
36 	 * 14-, 12-bit input code followed by 0, 2, or 4 don't care bits,
37 	 * for the AD5664R, AD5644R, and AD5624R, respectively.
38 	 */
39 	data = (0 << 22) | (cmd << 19) | (addr << 16) | (val << shift);
40 	put_unaligned_be24(data, &msg[0]);
41 
42 	return spi_write(spi, msg, sizeof(msg));
43 }
44 
45 static int ad5624r_read_raw(struct iio_dev *indio_dev,
46 			   struct iio_chan_spec const *chan,
47 			   int *val,
48 			   int *val2,
49 			   long m)
50 {
51 	struct ad5624r_state *st = iio_priv(indio_dev);
52 
53 	switch (m) {
54 	case IIO_CHAN_INFO_SCALE:
55 		*val = st->vref_mv;
56 		*val2 = chan->scan_type.realbits;
57 		return IIO_VAL_FRACTIONAL_LOG2;
58 	}
59 	return -EINVAL;
60 }
61 
62 static int ad5624r_write_raw(struct iio_dev *indio_dev,
63 			       struct iio_chan_spec const *chan,
64 			       int val,
65 			       int val2,
66 			       long mask)
67 {
68 	struct ad5624r_state *st = iio_priv(indio_dev);
69 
70 	switch (mask) {
71 	case IIO_CHAN_INFO_RAW:
72 		if (val >= (1 << chan->scan_type.realbits) || val < 0)
73 			return -EINVAL;
74 
75 		return ad5624r_spi_write(st->us,
76 				AD5624R_CMD_WRITE_INPUT_N_UPDATE_N,
77 				chan->address, val,
78 				chan->scan_type.shift);
79 	default:
80 		return -EINVAL;
81 	}
82 }
83 
84 static const char * const ad5624r_powerdown_modes[] = {
85 	"1kohm_to_gnd",
86 	"100kohm_to_gnd",
87 	"three_state"
88 };
89 
90 static int ad5624r_get_powerdown_mode(struct iio_dev *indio_dev,
91 	const struct iio_chan_spec *chan)
92 {
93 	struct ad5624r_state *st = iio_priv(indio_dev);
94 
95 	return st->pwr_down_mode;
96 }
97 
98 static int ad5624r_set_powerdown_mode(struct iio_dev *indio_dev,
99 	const struct iio_chan_spec *chan, unsigned int mode)
100 {
101 	struct ad5624r_state *st = iio_priv(indio_dev);
102 
103 	st->pwr_down_mode = mode;
104 
105 	return 0;
106 }
107 
108 static const struct iio_enum ad5624r_powerdown_mode_enum = {
109 	.items = ad5624r_powerdown_modes,
110 	.num_items = ARRAY_SIZE(ad5624r_powerdown_modes),
111 	.get = ad5624r_get_powerdown_mode,
112 	.set = ad5624r_set_powerdown_mode,
113 };
114 
115 static ssize_t ad5624r_read_dac_powerdown(struct iio_dev *indio_dev,
116 	uintptr_t private, const struct iio_chan_spec *chan, char *buf)
117 {
118 	struct ad5624r_state *st = iio_priv(indio_dev);
119 
120 	return sysfs_emit(buf, "%d\n",
121 			  !!(st->pwr_down_mask & (1 << chan->channel)));
122 }
123 
124 static ssize_t ad5624r_write_dac_powerdown(struct iio_dev *indio_dev,
125 	uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
126 	size_t len)
127 {
128 	bool pwr_down;
129 	int ret;
130 	struct ad5624r_state *st = iio_priv(indio_dev);
131 
132 	ret = kstrtobool(buf, &pwr_down);
133 	if (ret)
134 		return ret;
135 
136 	if (pwr_down)
137 		st->pwr_down_mask |= (1 << chan->channel);
138 	else
139 		st->pwr_down_mask &= ~(1 << chan->channel);
140 
141 	ret = ad5624r_spi_write(st->us, AD5624R_CMD_POWERDOWN_DAC, 0,
142 				(st->pwr_down_mode << 4) |
143 				st->pwr_down_mask, 16);
144 
145 	return ret ? ret : len;
146 }
147 
148 static const struct iio_info ad5624r_info = {
149 	.write_raw = ad5624r_write_raw,
150 	.read_raw = ad5624r_read_raw,
151 };
152 
153 static const struct iio_chan_spec_ext_info ad5624r_ext_info[] = {
154 	{
155 		.name = "powerdown",
156 		.read = ad5624r_read_dac_powerdown,
157 		.write = ad5624r_write_dac_powerdown,
158 		.shared = IIO_SEPARATE,
159 	},
160 	IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE,
161 		 &ad5624r_powerdown_mode_enum),
162 	IIO_ENUM_AVAILABLE("powerdown_mode", IIO_SHARED_BY_TYPE, &ad5624r_powerdown_mode_enum),
163 	{ },
164 };
165 
166 #define AD5624R_CHANNEL(_chan, _bits) { \
167 	.type = IIO_VOLTAGE, \
168 	.indexed = 1, \
169 	.output = 1, \
170 	.channel = (_chan), \
171 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
172 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
173 	.address = (_chan), \
174 	.scan_type = { \
175 		.sign = 'u', \
176 		.realbits = (_bits), \
177 		.storagebits = 16, \
178 		.shift = 16 - (_bits), \
179 	}, \
180 	.ext_info = ad5624r_ext_info, \
181 }
182 
183 #define DECLARE_AD5624R_CHANNELS(_name, _bits) \
184 	const struct iio_chan_spec _name##_channels[] = { \
185 		AD5624R_CHANNEL(0, _bits), \
186 		AD5624R_CHANNEL(1, _bits), \
187 		AD5624R_CHANNEL(2, _bits), \
188 		AD5624R_CHANNEL(3, _bits), \
189 }
190 
191 static DECLARE_AD5624R_CHANNELS(ad5624r, 12);
192 static DECLARE_AD5624R_CHANNELS(ad5644r, 14);
193 static DECLARE_AD5624R_CHANNELS(ad5664r, 16);
194 
195 static const struct ad5624r_chip_info ad5624r_chip_info_tbl[] = {
196 	[ID_AD5624R3] = {
197 		.channels = ad5624r_channels,
198 		.int_vref_mv = 1250,
199 	},
200 	[ID_AD5624R5] = {
201 		.channels = ad5624r_channels,
202 		.int_vref_mv = 2500,
203 	},
204 	[ID_AD5644R3] = {
205 		.channels = ad5644r_channels,
206 		.int_vref_mv = 1250,
207 	},
208 	[ID_AD5644R5] = {
209 		.channels = ad5644r_channels,
210 		.int_vref_mv = 2500,
211 	},
212 	[ID_AD5664R3] = {
213 		.channels = ad5664r_channels,
214 		.int_vref_mv = 1250,
215 	},
216 	[ID_AD5664R5] = {
217 		.channels = ad5664r_channels,
218 		.int_vref_mv = 2500,
219 	},
220 };
221 
222 static int ad5624r_probe(struct spi_device *spi)
223 {
224 	struct ad5624r_state *st;
225 	struct iio_dev *indio_dev;
226 	int ret, voltage_uv = 0;
227 
228 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
229 	if (!indio_dev)
230 		return -ENOMEM;
231 	st = iio_priv(indio_dev);
232 	st->reg = devm_regulator_get_optional(&spi->dev, "vref");
233 	if (!IS_ERR(st->reg)) {
234 		ret = regulator_enable(st->reg);
235 		if (ret)
236 			return ret;
237 
238 		ret = regulator_get_voltage(st->reg);
239 		if (ret < 0)
240 			goto error_disable_reg;
241 
242 		voltage_uv = ret;
243 	} else {
244 		if (PTR_ERR(st->reg) != -ENODEV)
245 			return PTR_ERR(st->reg);
246 		/* Backwards compatibility. This naming is not correct */
247 		st->reg = devm_regulator_get_optional(&spi->dev, "vcc");
248 		if (!IS_ERR(st->reg)) {
249 			ret = regulator_enable(st->reg);
250 			if (ret)
251 				return ret;
252 
253 			ret = regulator_get_voltage(st->reg);
254 			if (ret < 0)
255 				goto error_disable_reg;
256 
257 			voltage_uv = ret;
258 		}
259 	}
260 
261 	spi_set_drvdata(spi, indio_dev);
262 	st->chip_info =
263 		&ad5624r_chip_info_tbl[spi_get_device_id(spi)->driver_data];
264 
265 	if (voltage_uv)
266 		st->vref_mv = voltage_uv / 1000;
267 	else
268 		st->vref_mv = st->chip_info->int_vref_mv;
269 
270 	st->us = spi;
271 
272 	indio_dev->name = spi_get_device_id(spi)->name;
273 	indio_dev->info = &ad5624r_info;
274 	indio_dev->modes = INDIO_DIRECT_MODE;
275 	indio_dev->channels = st->chip_info->channels;
276 	indio_dev->num_channels = AD5624R_DAC_CHANNELS;
277 
278 	ret = ad5624r_spi_write(spi, AD5624R_CMD_INTERNAL_REFER_SETUP, 0,
279 				!!voltage_uv, 16);
280 	if (ret)
281 		goto error_disable_reg;
282 
283 	ret = iio_device_register(indio_dev);
284 	if (ret)
285 		goto error_disable_reg;
286 
287 	return 0;
288 
289 error_disable_reg:
290 	if (!IS_ERR(st->reg))
291 		regulator_disable(st->reg);
292 
293 	return ret;
294 }
295 
296 static void ad5624r_remove(struct spi_device *spi)
297 {
298 	struct iio_dev *indio_dev = spi_get_drvdata(spi);
299 	struct ad5624r_state *st = iio_priv(indio_dev);
300 
301 	iio_device_unregister(indio_dev);
302 	if (!IS_ERR(st->reg))
303 		regulator_disable(st->reg);
304 }
305 
306 static const struct spi_device_id ad5624r_id[] = {
307 	{"ad5624r3", ID_AD5624R3},
308 	{"ad5644r3", ID_AD5644R3},
309 	{"ad5664r3", ID_AD5664R3},
310 	{"ad5624r5", ID_AD5624R5},
311 	{"ad5644r5", ID_AD5644R5},
312 	{"ad5664r5", ID_AD5664R5},
313 	{}
314 };
315 MODULE_DEVICE_TABLE(spi, ad5624r_id);
316 
317 static struct spi_driver ad5624r_driver = {
318 	.driver = {
319 		   .name = "ad5624r",
320 		   },
321 	.probe = ad5624r_probe,
322 	.remove = ad5624r_remove,
323 	.id_table = ad5624r_id,
324 };
325 module_spi_driver(ad5624r_driver);
326 
327 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
328 MODULE_DESCRIPTION("Analog Devices AD5624/44/64R DAC spi driver");
329 MODULE_LICENSE("GPL v2");
330