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
19 #include <linux/iio/iio.h>
20 #include <linux/iio/sysfs.h>
21 #include <linux/iio/events.h>
22 #include <linux/iio/dac/ad5504.h>
23
24 #define AD5505_BITS 12
25 #define AD5504_RES_MASK ((1 << (AD5505_BITS)) - 1)
26
27 #define AD5504_CMD_READ (1 << 15)
28 #define AD5504_CMD_WRITE (0 << 15)
29 #define AD5504_ADDR(addr) ((addr) << 12)
30
31 /* Registers */
32 #define AD5504_ADDR_NOOP 0
33 #define AD5504_ADDR_DAC(x) ((x) + 1)
34 #define AD5504_ADDR_ALL_DAC 5
35 #define AD5504_ADDR_CTRL 7
36
37 /* Control Register */
38 #define AD5504_DAC_PWR(ch) ((ch) << 2)
39 #define AD5504_DAC_PWRDWN_MODE(mode) ((mode) << 6)
40 #define AD5504_DAC_PWRDN_20K 0
41 #define AD5504_DAC_PWRDN_3STATE 1
42
43 /**
44 * struct ad5446_state - driver instance specific data
45 * @us: spi_device
46 * @reg: supply regulator
47 * @vref_mv: actual reference voltage used
48 * @pwr_down_mask power down mask
49 * @pwr_down_mode current power down mode
50 */
51
52 struct ad5504_state {
53 struct spi_device *spi;
54 struct regulator *reg;
55 unsigned short vref_mv;
56 unsigned pwr_down_mask;
57 unsigned pwr_down_mode;
58 };
59
60 /**
61 * ad5504_supported_device_ids:
62 */
63
64 enum ad5504_supported_device_ids {
65 ID_AD5504,
66 ID_AD5501,
67 };
68
ad5504_spi_write(struct spi_device * spi,u8 addr,u16 val)69 static int ad5504_spi_write(struct spi_device *spi, u8 addr, u16 val)
70 {
71 u16 tmp = cpu_to_be16(AD5504_CMD_WRITE |
72 AD5504_ADDR(addr) |
73 (val & AD5504_RES_MASK));
74
75 return spi_write(spi, (u8 *)&tmp, 2);
76 }
77
ad5504_spi_read(struct spi_device * spi,u8 addr)78 static int ad5504_spi_read(struct spi_device *spi, u8 addr)
79 {
80 u16 tmp = cpu_to_be16(AD5504_CMD_READ | AD5504_ADDR(addr));
81 u16 val;
82 int ret;
83 struct spi_transfer t = {
84 .tx_buf = &tmp,
85 .rx_buf = &val,
86 .len = 2,
87 };
88 ret = spi_sync_transfer(spi, &t, 1);
89
90 if (ret < 0)
91 return ret;
92
93 return be16_to_cpu(val) & AD5504_RES_MASK;
94 }
95
ad5504_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long m)96 static int ad5504_read_raw(struct iio_dev *indio_dev,
97 struct iio_chan_spec const *chan,
98 int *val,
99 int *val2,
100 long m)
101 {
102 struct ad5504_state *st = iio_priv(indio_dev);
103 unsigned long scale_uv;
104 int ret;
105
106 switch (m) {
107 case IIO_CHAN_INFO_RAW:
108 ret = ad5504_spi_read(st->spi, chan->address);
109 if (ret < 0)
110 return ret;
111
112 *val = ret;
113
114 return IIO_VAL_INT;
115 case IIO_CHAN_INFO_SCALE:
116 scale_uv = (st->vref_mv * 1000) >> chan->scan_type.realbits;
117 *val = scale_uv / 1000;
118 *val2 = (scale_uv % 1000) * 1000;
119 return IIO_VAL_INT_PLUS_MICRO;
120
121 }
122 return -EINVAL;
123 }
124
ad5504_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)125 static int ad5504_write_raw(struct iio_dev *indio_dev,
126 struct iio_chan_spec const *chan,
127 int val,
128 int val2,
129 long mask)
130 {
131 struct ad5504_state *st = iio_priv(indio_dev);
132 int ret;
133
134 switch (mask) {
135 case IIO_CHAN_INFO_RAW:
136 if (val >= (1 << chan->scan_type.realbits) || val < 0)
137 return -EINVAL;
138
139 return ad5504_spi_write(st->spi, chan->address, val);
140 default:
141 ret = -EINVAL;
142 }
143
144 return -EINVAL;
145 }
146
147 static const char * const ad5504_powerdown_modes[] = {
148 "20kohm_to_gnd",
149 "three_state",
150 };
151
ad5504_get_powerdown_mode(struct iio_dev * indio_dev,const struct iio_chan_spec * chan)152 static int ad5504_get_powerdown_mode(struct iio_dev *indio_dev,
153 const struct iio_chan_spec *chan)
154 {
155 struct ad5504_state *st = iio_priv(indio_dev);
156
157 return st->pwr_down_mode;
158 }
159
ad5504_set_powerdown_mode(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,unsigned int mode)160 static int ad5504_set_powerdown_mode(struct iio_dev *indio_dev,
161 const struct iio_chan_spec *chan, unsigned int mode)
162 {
163 struct ad5504_state *st = iio_priv(indio_dev);
164
165 st->pwr_down_mode = mode;
166
167 return 0;
168 }
169
170 static const struct iio_enum ad5504_powerdown_mode_enum = {
171 .items = ad5504_powerdown_modes,
172 .num_items = ARRAY_SIZE(ad5504_powerdown_modes),
173 .get = ad5504_get_powerdown_mode,
174 .set = ad5504_set_powerdown_mode,
175 };
176
ad5504_read_dac_powerdown(struct iio_dev * indio_dev,uintptr_t private,const struct iio_chan_spec * chan,char * buf)177 static ssize_t ad5504_read_dac_powerdown(struct iio_dev *indio_dev,
178 uintptr_t private, const struct iio_chan_spec *chan, char *buf)
179 {
180 struct ad5504_state *st = iio_priv(indio_dev);
181
182 return sprintf(buf, "%d\n",
183 !(st->pwr_down_mask & (1 << chan->channel)));
184 }
185
ad5504_write_dac_powerdown(struct iio_dev * indio_dev,uintptr_t private,const struct iio_chan_spec * chan,const char * buf,size_t len)186 static ssize_t ad5504_write_dac_powerdown(struct iio_dev *indio_dev,
187 uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
188 size_t len)
189 {
190 bool pwr_down;
191 int ret;
192 struct ad5504_state *st = iio_priv(indio_dev);
193
194 ret = strtobool(buf, &pwr_down);
195 if (ret)
196 return ret;
197
198 if (pwr_down)
199 st->pwr_down_mask |= (1 << chan->channel);
200 else
201 st->pwr_down_mask &= ~(1 << chan->channel);
202
203 ret = ad5504_spi_write(st->spi, AD5504_ADDR_CTRL,
204 AD5504_DAC_PWRDWN_MODE(st->pwr_down_mode) |
205 AD5504_DAC_PWR(st->pwr_down_mask));
206
207 /* writes to the CTRL register must be followed by a NOOP */
208 ad5504_spi_write(st->spi, AD5504_ADDR_NOOP, 0);
209
210 return ret ? ret : len;
211 }
212
213 static IIO_CONST_ATTR(temp0_thresh_rising_value, "110000");
214 static IIO_CONST_ATTR(temp0_thresh_rising_en, "1");
215
216 static struct attribute *ad5504_ev_attributes[] = {
217 &iio_const_attr_temp0_thresh_rising_value.dev_attr.attr,
218 &iio_const_attr_temp0_thresh_rising_en.dev_attr.attr,
219 NULL,
220 };
221
222 static struct attribute_group ad5504_ev_attribute_group = {
223 .attrs = ad5504_ev_attributes,
224 .name = "events",
225 };
226
ad5504_event_handler(int irq,void * private)227 static irqreturn_t ad5504_event_handler(int irq, void *private)
228 {
229 iio_push_event(private,
230 IIO_UNMOD_EVENT_CODE(IIO_TEMP,
231 0,
232 IIO_EV_TYPE_THRESH,
233 IIO_EV_DIR_RISING),
234 iio_get_time_ns());
235
236 return IRQ_HANDLED;
237 }
238
239 static const struct iio_info ad5504_info = {
240 .write_raw = ad5504_write_raw,
241 .read_raw = ad5504_read_raw,
242 .event_attrs = &ad5504_ev_attribute_group,
243 .driver_module = THIS_MODULE,
244 };
245
246 static const struct iio_chan_spec_ext_info ad5504_ext_info[] = {
247 {
248 .name = "powerdown",
249 .read = ad5504_read_dac_powerdown,
250 .write = ad5504_write_dac_powerdown,
251 },
252 IIO_ENUM("powerdown_mode", true, &ad5504_powerdown_mode_enum),
253 IIO_ENUM_AVAILABLE("powerdown_mode", &ad5504_powerdown_mode_enum),
254 { },
255 };
256
257 #define AD5504_CHANNEL(_chan) { \
258 .type = IIO_VOLTAGE, \
259 .indexed = 1, \
260 .output = 1, \
261 .channel = (_chan), \
262 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
263 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
264 .address = AD5504_ADDR_DAC(_chan), \
265 .scan_type = IIO_ST('u', 12, 16, 0), \
266 .ext_info = ad5504_ext_info, \
267 }
268
269 static const struct iio_chan_spec ad5504_channels[] = {
270 AD5504_CHANNEL(0),
271 AD5504_CHANNEL(1),
272 AD5504_CHANNEL(2),
273 AD5504_CHANNEL(3),
274 };
275
ad5504_probe(struct spi_device * spi)276 static int ad5504_probe(struct spi_device *spi)
277 {
278 struct ad5504_platform_data *pdata = spi->dev.platform_data;
279 struct iio_dev *indio_dev;
280 struct ad5504_state *st;
281 struct regulator *reg;
282 int ret, voltage_uv = 0;
283
284 indio_dev = iio_device_alloc(sizeof(*st));
285 if (indio_dev == NULL) {
286 ret = -ENOMEM;
287 goto error_ret;
288 }
289 reg = regulator_get(&spi->dev, "vcc");
290 if (!IS_ERR(reg)) {
291 ret = regulator_enable(reg);
292 if (ret)
293 goto error_put_reg;
294
295 ret = regulator_get_voltage(reg);
296 if (ret < 0)
297 goto error_disable_reg;
298
299 voltage_uv = ret;
300 }
301
302 spi_set_drvdata(spi, indio_dev);
303 st = iio_priv(indio_dev);
304 if (voltage_uv)
305 st->vref_mv = voltage_uv / 1000;
306 else if (pdata)
307 st->vref_mv = pdata->vref_mv;
308 else
309 dev_warn(&spi->dev, "reference voltage unspecified\n");
310
311 st->reg = reg;
312 st->spi = spi;
313 indio_dev->dev.parent = &spi->dev;
314 indio_dev->name = spi_get_device_id(st->spi)->name;
315 indio_dev->info = &ad5504_info;
316 if (spi_get_device_id(st->spi)->driver_data == ID_AD5501)
317 indio_dev->num_channels = 1;
318 else
319 indio_dev->num_channels = 4;
320 indio_dev->channels = ad5504_channels;
321 indio_dev->modes = INDIO_DIRECT_MODE;
322
323 if (spi->irq) {
324 ret = request_threaded_irq(spi->irq,
325 NULL,
326 &ad5504_event_handler,
327 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
328 spi_get_device_id(st->spi)->name,
329 indio_dev);
330 if (ret)
331 goto error_disable_reg;
332 }
333
334 ret = iio_device_register(indio_dev);
335 if (ret)
336 goto error_free_irq;
337
338 return 0;
339
340 error_free_irq:
341 if (spi->irq)
342 free_irq(spi->irq, indio_dev);
343 error_disable_reg:
344 if (!IS_ERR(reg))
345 regulator_disable(reg);
346 error_put_reg:
347 if (!IS_ERR(reg))
348 regulator_put(reg);
349
350 iio_device_free(indio_dev);
351 error_ret:
352 return ret;
353 }
354
ad5504_remove(struct spi_device * spi)355 static int ad5504_remove(struct spi_device *spi)
356 {
357 struct iio_dev *indio_dev = spi_get_drvdata(spi);
358 struct ad5504_state *st = iio_priv(indio_dev);
359
360 iio_device_unregister(indio_dev);
361 if (spi->irq)
362 free_irq(spi->irq, indio_dev);
363
364 if (!IS_ERR(st->reg)) {
365 regulator_disable(st->reg);
366 regulator_put(st->reg);
367 }
368 iio_device_free(indio_dev);
369
370 return 0;
371 }
372
373 static const struct spi_device_id ad5504_id[] = {
374 {"ad5504", ID_AD5504},
375 {"ad5501", ID_AD5501},
376 {}
377 };
378 MODULE_DEVICE_TABLE(spi, ad5504_id);
379
380 static struct spi_driver ad5504_driver = {
381 .driver = {
382 .name = "ad5504",
383 .owner = THIS_MODULE,
384 },
385 .probe = ad5504_probe,
386 .remove = ad5504_remove,
387 .id_table = ad5504_id,
388 };
389 module_spi_driver(ad5504_driver);
390
391 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
392 MODULE_DESCRIPTION("Analog Devices AD5501/AD5501 DAC");
393 MODULE_LICENSE("GPL v2");
394