GNU Linux-libre 4.19.314-gnu1
[releases.git] / drivers / iio / dac / ad5504.c
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
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
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
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
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
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
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
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
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
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
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
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");