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