1 /*
2 * AD5504, AD5501 High Voltage Digital to Analog Converter
3 *
4 * Copyright 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 #include <linux/bitops.h>
19
20 #include <linux/iio/iio.h>
21 #include <linux/iio/sysfs.h>
22 #include <linux/iio/events.h>
23 #include <linux/iio/dac/ad5504.h>
24
25 #define AD5504_RES_MASK GENMASK(11, 0)
26 #define AD5504_CMD_READ BIT(15)
27 #define AD5504_CMD_WRITE 0
28 #define AD5504_ADDR(addr) ((addr) << 12)
29
30 /* Registers */
31 #define AD5504_ADDR_NOOP 0
32 #define AD5504_ADDR_DAC(x) ((x) + 1)
33 #define AD5504_ADDR_ALL_DAC 5
34 #define AD5504_ADDR_CTRL 7
35
36 /* Control Register */
37 #define AD5504_DAC_PWR(ch) ((ch) << 2)
38 #define AD5504_DAC_PWRDWN_MODE(mode) ((mode) << 6)
39 #define AD5504_DAC_PWRDN_20K 0
40 #define AD5504_DAC_PWRDN_3STATE 1
41
42 /**
43 * struct ad5446_state - driver instance specific data
44 * @spi: spi_device
45 * @reg: supply regulator
46 * @vref_mv: actual reference voltage used
47 * @pwr_down_mask power down mask
48 * @pwr_down_mode current power down mode
49 * @data: transfer buffer
50 */
51 struct ad5504_state {
52 struct spi_device *spi;
53 struct regulator *reg;
54 unsigned short vref_mv;
55 unsigned pwr_down_mask;
56 unsigned pwr_down_mode;
57
58 __be16 data[2] ____cacheline_aligned;
59 };
60
61 /**
62 * ad5504_supported_device_ids:
63 */
64
65 enum ad5504_supported_device_ids {
66 ID_AD5504,
67 ID_AD5501,
68 };
69
ad5504_spi_write(struct ad5504_state * st,u8 addr,u16 val)70 static int ad5504_spi_write(struct ad5504_state *st, u8 addr, u16 val)
71 {
72 st->data[0] = cpu_to_be16(AD5504_CMD_WRITE | AD5504_ADDR(addr) |
73 (val & AD5504_RES_MASK));
74
75 return spi_write(st->spi, &st->data[0], 2);
76 }
77
ad5504_spi_read(struct ad5504_state * st,u8 addr)78 static int ad5504_spi_read(struct ad5504_state *st, u8 addr)
79 {
80 int ret;
81 struct spi_transfer t = {
82 .tx_buf = &st->data[0],
83 .rx_buf = &st->data[1],
84 .len = 2,
85 };
86
87 st->data[0] = cpu_to_be16(AD5504_CMD_READ | AD5504_ADDR(addr));
88 ret = spi_sync_transfer(st->spi, &t, 1);
89 if (ret < 0)
90 return ret;
91
92 return be16_to_cpu(st->data[1]) & AD5504_RES_MASK;
93 }
94
ad5504_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long m)95 static int ad5504_read_raw(struct iio_dev *indio_dev,
96 struct iio_chan_spec const *chan,
97 int *val,
98 int *val2,
99 long m)
100 {
101 struct ad5504_state *st = iio_priv(indio_dev);
102 int ret;
103
104 switch (m) {
105 case IIO_CHAN_INFO_RAW:
106 ret = ad5504_spi_read(st, chan->address);
107 if (ret < 0)
108 return ret;
109
110 *val = ret;
111
112 return IIO_VAL_INT;
113 case IIO_CHAN_INFO_SCALE:
114 *val = st->vref_mv;
115 *val2 = chan->scan_type.realbits;
116 return IIO_VAL_FRACTIONAL_LOG2;
117 }
118 return -EINVAL;
119 }
120
ad5504_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)121 static int ad5504_write_raw(struct iio_dev *indio_dev,
122 struct iio_chan_spec const *chan,
123 int val,
124 int val2,
125 long mask)
126 {
127 struct ad5504_state *st = iio_priv(indio_dev);
128
129 switch (mask) {
130 case IIO_CHAN_INFO_RAW:
131 if (val >= (1 << chan->scan_type.realbits) || val < 0)
132 return -EINVAL;
133
134 return ad5504_spi_write(st, chan->address, val);
135 default:
136 return -EINVAL;
137 }
138 }
139
140 static const char * const ad5504_powerdown_modes[] = {
141 "20kohm_to_gnd",
142 "three_state",
143 };
144
ad5504_get_powerdown_mode(struct iio_dev * indio_dev,const struct iio_chan_spec * chan)145 static int ad5504_get_powerdown_mode(struct iio_dev *indio_dev,
146 const struct iio_chan_spec *chan)
147 {
148 struct ad5504_state *st = iio_priv(indio_dev);
149
150 return st->pwr_down_mode;
151 }
152
ad5504_set_powerdown_mode(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,unsigned int mode)153 static int ad5504_set_powerdown_mode(struct iio_dev *indio_dev,
154 const struct iio_chan_spec *chan, unsigned int mode)
155 {
156 struct ad5504_state *st = iio_priv(indio_dev);
157
158 st->pwr_down_mode = mode;
159
160 return 0;
161 }
162
163 static const struct iio_enum ad5504_powerdown_mode_enum = {
164 .items = ad5504_powerdown_modes,
165 .num_items = ARRAY_SIZE(ad5504_powerdown_modes),
166 .get = ad5504_get_powerdown_mode,
167 .set = ad5504_set_powerdown_mode,
168 };
169
ad5504_read_dac_powerdown(struct iio_dev * indio_dev,uintptr_t private,const struct iio_chan_spec * chan,char * buf)170 static ssize_t ad5504_read_dac_powerdown(struct iio_dev *indio_dev,
171 uintptr_t private, const struct iio_chan_spec *chan, char *buf)
172 {
173 struct ad5504_state *st = iio_priv(indio_dev);
174
175 return sprintf(buf, "%d\n",
176 !(st->pwr_down_mask & (1 << chan->channel)));
177 }
178
ad5504_write_dac_powerdown(struct iio_dev * indio_dev,uintptr_t private,const struct iio_chan_spec * chan,const char * buf,size_t len)179 static ssize_t ad5504_write_dac_powerdown(struct iio_dev *indio_dev,
180 uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
181 size_t len)
182 {
183 bool pwr_down;
184 int ret;
185 struct ad5504_state *st = iio_priv(indio_dev);
186
187 ret = strtobool(buf, &pwr_down);
188 if (ret)
189 return ret;
190
191 if (pwr_down)
192 st->pwr_down_mask &= ~(1 << chan->channel);
193 else
194 st->pwr_down_mask |= (1 << chan->channel);
195
196 ret = ad5504_spi_write(st, AD5504_ADDR_CTRL,
197 AD5504_DAC_PWRDWN_MODE(st->pwr_down_mode) |
198 AD5504_DAC_PWR(st->pwr_down_mask));
199
200 /* writes to the CTRL register must be followed by a NOOP */
201 ad5504_spi_write(st, AD5504_ADDR_NOOP, 0);
202
203 return ret ? ret : len;
204 }
205
206 static IIO_CONST_ATTR(temp0_thresh_rising_value, "110000");
207 static IIO_CONST_ATTR(temp0_thresh_rising_en, "1");
208
209 static struct attribute *ad5504_ev_attributes[] = {
210 &iio_const_attr_temp0_thresh_rising_value.dev_attr.attr,
211 &iio_const_attr_temp0_thresh_rising_en.dev_attr.attr,
212 NULL,
213 };
214
215 static const struct attribute_group ad5504_ev_attribute_group = {
216 .attrs = ad5504_ev_attributes,
217 };
218
ad5504_event_handler(int irq,void * private)219 static irqreturn_t ad5504_event_handler(int irq, void *private)
220 {
221 iio_push_event(private,
222 IIO_UNMOD_EVENT_CODE(IIO_TEMP,
223 0,
224 IIO_EV_TYPE_THRESH,
225 IIO_EV_DIR_RISING),
226 iio_get_time_ns(private));
227
228 return IRQ_HANDLED;
229 }
230
231 static const struct iio_info ad5504_info = {
232 .write_raw = ad5504_write_raw,
233 .read_raw = ad5504_read_raw,
234 .event_attrs = &ad5504_ev_attribute_group,
235 };
236
237 static const struct iio_chan_spec_ext_info ad5504_ext_info[] = {
238 {
239 .name = "powerdown",
240 .read = ad5504_read_dac_powerdown,
241 .write = ad5504_write_dac_powerdown,
242 .shared = IIO_SEPARATE,
243 },
244 IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE,
245 &ad5504_powerdown_mode_enum),
246 IIO_ENUM_AVAILABLE("powerdown_mode", &ad5504_powerdown_mode_enum),
247 { },
248 };
249
250 #define AD5504_CHANNEL(_chan) { \
251 .type = IIO_VOLTAGE, \
252 .indexed = 1, \
253 .output = 1, \
254 .channel = (_chan), \
255 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
256 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
257 .address = AD5504_ADDR_DAC(_chan), \
258 .scan_type = { \
259 .sign = 'u', \
260 .realbits = 12, \
261 .storagebits = 16, \
262 }, \
263 .ext_info = ad5504_ext_info, \
264 }
265
266 static const struct iio_chan_spec ad5504_channels[] = {
267 AD5504_CHANNEL(0),
268 AD5504_CHANNEL(1),
269 AD5504_CHANNEL(2),
270 AD5504_CHANNEL(3),
271 };
272
ad5504_probe(struct spi_device * spi)273 static int ad5504_probe(struct spi_device *spi)
274 {
275 struct ad5504_platform_data *pdata = spi->dev.platform_data;
276 struct iio_dev *indio_dev;
277 struct ad5504_state *st;
278 struct regulator *reg;
279 int ret, voltage_uv = 0;
280
281 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
282 if (!indio_dev)
283 return -ENOMEM;
284 reg = devm_regulator_get(&spi->dev, "vcc");
285 if (!IS_ERR(reg)) {
286 ret = regulator_enable(reg);
287 if (ret)
288 return ret;
289
290 ret = regulator_get_voltage(reg);
291 if (ret < 0)
292 goto error_disable_reg;
293
294 voltage_uv = ret;
295 }
296
297 spi_set_drvdata(spi, indio_dev);
298 st = iio_priv(indio_dev);
299 if (voltage_uv)
300 st->vref_mv = voltage_uv / 1000;
301 else if (pdata)
302 st->vref_mv = pdata->vref_mv;
303 else
304 dev_warn(&spi->dev, "reference voltage unspecified\n");
305
306 st->reg = reg;
307 st->spi = spi;
308 indio_dev->dev.parent = &spi->dev;
309 indio_dev->name = spi_get_device_id(st->spi)->name;
310 indio_dev->info = &ad5504_info;
311 if (spi_get_device_id(st->spi)->driver_data == ID_AD5501)
312 indio_dev->num_channels = 1;
313 else
314 indio_dev->num_channels = 4;
315 indio_dev->channels = ad5504_channels;
316 indio_dev->modes = INDIO_DIRECT_MODE;
317
318 if (spi->irq) {
319 ret = devm_request_threaded_irq(&spi->dev, spi->irq,
320 NULL,
321 &ad5504_event_handler,
322 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
323 spi_get_device_id(st->spi)->name,
324 indio_dev);
325 if (ret)
326 goto error_disable_reg;
327 }
328
329 ret = iio_device_register(indio_dev);
330 if (ret)
331 goto error_disable_reg;
332
333 return 0;
334
335 error_disable_reg:
336 if (!IS_ERR(reg))
337 regulator_disable(reg);
338
339 return ret;
340 }
341
ad5504_remove(struct spi_device * spi)342 static int ad5504_remove(struct spi_device *spi)
343 {
344 struct iio_dev *indio_dev = spi_get_drvdata(spi);
345 struct ad5504_state *st = iio_priv(indio_dev);
346
347 iio_device_unregister(indio_dev);
348
349 if (!IS_ERR(st->reg))
350 regulator_disable(st->reg);
351
352 return 0;
353 }
354
355 static const struct spi_device_id ad5504_id[] = {
356 {"ad5504", ID_AD5504},
357 {"ad5501", ID_AD5501},
358 {}
359 };
360 MODULE_DEVICE_TABLE(spi, ad5504_id);
361
362 static struct spi_driver ad5504_driver = {
363 .driver = {
364 .name = "ad5504",
365 },
366 .probe = ad5504_probe,
367 .remove = ad5504_remove,
368 .id_table = ad5504_id,
369 };
370 module_spi_driver(ad5504_driver);
371
372 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
373 MODULE_DESCRIPTION("Analog Devices AD5501/AD5501 DAC");
374 MODULE_LICENSE("GPL v2");
375