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 len)24 static int ad5624r_spi_write(struct spi_device *spi,
25 u8 cmd, u8 addr, u16 val, u8 len)
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 << (16 - len));
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 unsigned long scale_uv;
54
55 switch (m) {
56 case IIO_CHAN_INFO_SCALE:
57 scale_uv = (st->vref_mv * 1000) >> chan->scan_type.realbits;
58 *val = scale_uv / 1000;
59 *val2 = (scale_uv % 1000) * 1000;
60 return IIO_VAL_INT_PLUS_MICRO;
61
62 }
63 return -EINVAL;
64 }
65
ad5624r_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)66 static int ad5624r_write_raw(struct iio_dev *indio_dev,
67 struct iio_chan_spec const *chan,
68 int val,
69 int val2,
70 long mask)
71 {
72 struct ad5624r_state *st = iio_priv(indio_dev);
73 int ret;
74
75 switch (mask) {
76 case IIO_CHAN_INFO_RAW:
77 if (val >= (1 << chan->scan_type.realbits) || val < 0)
78 return -EINVAL;
79
80 return ad5624r_spi_write(st->us,
81 AD5624R_CMD_WRITE_INPUT_N_UPDATE_N,
82 chan->address, val,
83 chan->scan_type.shift);
84 default:
85 ret = -EINVAL;
86 }
87
88 return -EINVAL;
89 }
90
91 static const char * const ad5624r_powerdown_modes[] = {
92 "1kohm_to_gnd",
93 "100kohm_to_gnd",
94 "three_state"
95 };
96
ad5624r_get_powerdown_mode(struct iio_dev * indio_dev,const struct iio_chan_spec * chan)97 static int ad5624r_get_powerdown_mode(struct iio_dev *indio_dev,
98 const struct iio_chan_spec *chan)
99 {
100 struct ad5624r_state *st = iio_priv(indio_dev);
101
102 return st->pwr_down_mode;
103 }
104
ad5624r_set_powerdown_mode(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,unsigned int mode)105 static int ad5624r_set_powerdown_mode(struct iio_dev *indio_dev,
106 const struct iio_chan_spec *chan, unsigned int mode)
107 {
108 struct ad5624r_state *st = iio_priv(indio_dev);
109
110 st->pwr_down_mode = mode;
111
112 return 0;
113 }
114
115 static const struct iio_enum ad5624r_powerdown_mode_enum = {
116 .items = ad5624r_powerdown_modes,
117 .num_items = ARRAY_SIZE(ad5624r_powerdown_modes),
118 .get = ad5624r_get_powerdown_mode,
119 .set = ad5624r_set_powerdown_mode,
120 };
121
ad5624r_read_dac_powerdown(struct iio_dev * indio_dev,uintptr_t private,const struct iio_chan_spec * chan,char * buf)122 static ssize_t ad5624r_read_dac_powerdown(struct iio_dev *indio_dev,
123 uintptr_t private, const struct iio_chan_spec *chan, char *buf)
124 {
125 struct ad5624r_state *st = iio_priv(indio_dev);
126
127 return sprintf(buf, "%d\n",
128 !!(st->pwr_down_mask & (1 << chan->channel)));
129 }
130
ad5624r_write_dac_powerdown(struct iio_dev * indio_dev,uintptr_t private,const struct iio_chan_spec * chan,const char * buf,size_t len)131 static ssize_t ad5624r_write_dac_powerdown(struct iio_dev *indio_dev,
132 uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
133 size_t len)
134 {
135 bool pwr_down;
136 int ret;
137 struct ad5624r_state *st = iio_priv(indio_dev);
138
139 ret = strtobool(buf, &pwr_down);
140 if (ret)
141 return ret;
142
143 if (pwr_down)
144 st->pwr_down_mask |= (1 << chan->channel);
145 else
146 st->pwr_down_mask &= ~(1 << chan->channel);
147
148 ret = ad5624r_spi_write(st->us, AD5624R_CMD_POWERDOWN_DAC, 0,
149 (st->pwr_down_mode << 4) |
150 st->pwr_down_mask, 16);
151
152 return ret ? ret : len;
153 }
154
155 static const struct iio_info ad5624r_info = {
156 .write_raw = ad5624r_write_raw,
157 .read_raw = ad5624r_read_raw,
158 .driver_module = THIS_MODULE,
159 };
160
161 static const struct iio_chan_spec_ext_info ad5624r_ext_info[] = {
162 {
163 .name = "powerdown",
164 .read = ad5624r_read_dac_powerdown,
165 .write = ad5624r_write_dac_powerdown,
166 },
167 IIO_ENUM("powerdown_mode", true, &ad5624r_powerdown_mode_enum),
168 IIO_ENUM_AVAILABLE("powerdown_mode", &ad5624r_powerdown_mode_enum),
169 { },
170 };
171
172 #define AD5624R_CHANNEL(_chan, _bits) { \
173 .type = IIO_VOLTAGE, \
174 .indexed = 1, \
175 .output = 1, \
176 .channel = (_chan), \
177 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
178 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
179 .address = (_chan), \
180 .scan_type = IIO_ST('u', (_bits), 16, 16 - (_bits)), \
181 .ext_info = ad5624r_ext_info, \
182 }
183
184 #define DECLARE_AD5624R_CHANNELS(_name, _bits) \
185 const struct iio_chan_spec _name##_channels[] = { \
186 AD5624R_CHANNEL(0, _bits), \
187 AD5624R_CHANNEL(1, _bits), \
188 AD5624R_CHANNEL(2, _bits), \
189 AD5624R_CHANNEL(3, _bits), \
190 }
191
192 static DECLARE_AD5624R_CHANNELS(ad5624r, 12);
193 static DECLARE_AD5624R_CHANNELS(ad5644r, 14);
194 static DECLARE_AD5624R_CHANNELS(ad5664r, 16);
195
196 static const struct ad5624r_chip_info ad5624r_chip_info_tbl[] = {
197 [ID_AD5624R3] = {
198 .channels = ad5624r_channels,
199 .int_vref_mv = 1250,
200 },
201 [ID_AD5624R5] = {
202 .channels = ad5624r_channels,
203 .int_vref_mv = 2500,
204 },
205 [ID_AD5644R3] = {
206 .channels = ad5644r_channels,
207 .int_vref_mv = 1250,
208 },
209 [ID_AD5644R5] = {
210 .channels = ad5644r_channels,
211 .int_vref_mv = 2500,
212 },
213 [ID_AD5664R3] = {
214 .channels = ad5664r_channels,
215 .int_vref_mv = 1250,
216 },
217 [ID_AD5664R5] = {
218 .channels = ad5664r_channels,
219 .int_vref_mv = 2500,
220 },
221 };
222
ad5624r_probe(struct spi_device * spi)223 static int ad5624r_probe(struct spi_device *spi)
224 {
225 struct ad5624r_state *st;
226 struct iio_dev *indio_dev;
227 int ret, voltage_uv = 0;
228
229 indio_dev = iio_device_alloc(sizeof(*st));
230 if (indio_dev == NULL) {
231 ret = -ENOMEM;
232 goto error_ret;
233 }
234 st = iio_priv(indio_dev);
235 st->reg = regulator_get(&spi->dev, "vcc");
236 if (!IS_ERR(st->reg)) {
237 ret = regulator_enable(st->reg);
238 if (ret)
239 goto error_put_reg;
240
241 ret = regulator_get_voltage(st->reg);
242 if (ret < 0)
243 goto error_disable_reg;
244
245 voltage_uv = ret;
246 }
247
248 spi_set_drvdata(spi, indio_dev);
249 st->chip_info =
250 &ad5624r_chip_info_tbl[spi_get_device_id(spi)->driver_data];
251
252 if (voltage_uv)
253 st->vref_mv = voltage_uv / 1000;
254 else
255 st->vref_mv = st->chip_info->int_vref_mv;
256
257 st->us = spi;
258
259 indio_dev->dev.parent = &spi->dev;
260 indio_dev->name = spi_get_device_id(spi)->name;
261 indio_dev->info = &ad5624r_info;
262 indio_dev->modes = INDIO_DIRECT_MODE;
263 indio_dev->channels = st->chip_info->channels;
264 indio_dev->num_channels = AD5624R_DAC_CHANNELS;
265
266 ret = ad5624r_spi_write(spi, AD5624R_CMD_INTERNAL_REFER_SETUP, 0,
267 !!voltage_uv, 16);
268 if (ret)
269 goto error_disable_reg;
270
271 ret = iio_device_register(indio_dev);
272 if (ret)
273 goto error_disable_reg;
274
275 return 0;
276
277 error_disable_reg:
278 if (!IS_ERR(st->reg))
279 regulator_disable(st->reg);
280 error_put_reg:
281 if (!IS_ERR(st->reg))
282 regulator_put(st->reg);
283 iio_device_free(indio_dev);
284 error_ret:
285
286 return ret;
287 }
288
ad5624r_remove(struct spi_device * spi)289 static int ad5624r_remove(struct spi_device *spi)
290 {
291 struct iio_dev *indio_dev = spi_get_drvdata(spi);
292 struct ad5624r_state *st = iio_priv(indio_dev);
293
294 iio_device_unregister(indio_dev);
295 if (!IS_ERR(st->reg)) {
296 regulator_disable(st->reg);
297 regulator_put(st->reg);
298 }
299 iio_device_free(indio_dev);
300
301 return 0;
302 }
303
304 static const struct spi_device_id ad5624r_id[] = {
305 {"ad5624r3", ID_AD5624R3},
306 {"ad5644r3", ID_AD5644R3},
307 {"ad5664r3", ID_AD5664R3},
308 {"ad5624r5", ID_AD5624R5},
309 {"ad5644r5", ID_AD5644R5},
310 {"ad5664r5", ID_AD5664R5},
311 {}
312 };
313 MODULE_DEVICE_TABLE(spi, ad5624r_id);
314
315 static struct spi_driver ad5624r_driver = {
316 .driver = {
317 .name = "ad5624r",
318 .owner = THIS_MODULE,
319 },
320 .probe = ad5624r_probe,
321 .remove = ad5624r_remove,
322 .id_table = ad5624r_id,
323 };
324 module_spi_driver(ad5624r_driver);
325
326 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
327 MODULE_DESCRIPTION("Analog Devices AD5624/44/64R DAC spi driver");
328 MODULE_LICENSE("GPL v2");
329