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