2 * AD7780/AD7781 SPI ADC driver
4 * Copyright 2011 Analog Devices Inc.
6 * Licensed under the GPL-2.
9 #include <linux/interrupt.h>
10 #include <linux/device.h>
11 #include <linux/kernel.h>
12 #include <linux/slab.h>
13 #include <linux/sysfs.h>
14 #include <linux/spi/spi.h>
15 #include <linux/regulator/consumer.h>
16 #include <linux/err.h>
17 #include <linux/sched.h>
18 #include <linux/gpio.h>
19 #include <linux/module.h>
21 #include <linux/iio/iio.h>
22 #include <linux/iio/sysfs.h>
23 #include <linux/iio/adc/ad_sigma_delta.h>
27 #define AD7780_RDY (1 << 7)
28 #define AD7780_FILTER (1 << 6)
29 #define AD7780_ERR (1 << 5)
30 #define AD7780_ID1 (1 << 4)
31 #define AD7780_ID0 (1 << 3)
32 #define AD7780_GAIN (1 << 2)
33 #define AD7780_PAT1 (1 << 1)
34 #define AD7780_PAT0 (1 << 0)
36 struct ad7780_chip_info {
37 struct iio_chan_spec channel;
41 const struct ad7780_chip_info *chip_info;
42 struct regulator *reg;
47 struct ad_sigma_delta sd;
50 enum ad7780_supported_device_ids {
55 static struct ad7780_state *ad_sigma_delta_to_ad7780(struct ad_sigma_delta *sd)
57 return container_of(sd, struct ad7780_state, sd);
60 static int ad7780_set_mode(struct ad_sigma_delta *sigma_delta,
61 enum ad_sigma_delta_mode mode)
63 struct ad7780_state *st = ad_sigma_delta_to_ad7780(sigma_delta);
67 case AD_SD_MODE_SINGLE:
68 case AD_SD_MODE_CONTINUOUS:
76 if (gpio_is_valid(st->powerdown_gpio))
77 gpio_set_value(st->powerdown_gpio, val);
82 static int ad7780_read_raw(struct iio_dev *indio_dev,
83 struct iio_chan_spec const *chan,
88 struct ad7780_state *st = iio_priv(indio_dev);
89 unsigned long scale_uv;
92 case IIO_CHAN_INFO_RAW:
93 return ad_sigma_delta_single_conversion(indio_dev, chan, val);
94 case IIO_CHAN_INFO_SCALE:
95 scale_uv = (st->int_vref_mv * 100000 * st->gain)
96 >> (chan->scan_type.realbits - 1);
97 *val = scale_uv / 100000;
98 *val2 = (scale_uv % 100000) * 10;
99 return IIO_VAL_INT_PLUS_MICRO;
100 case IIO_CHAN_INFO_OFFSET:
101 *val -= (1 << (chan->scan_type.realbits - 1));
108 static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta,
109 unsigned int raw_sample)
111 struct ad7780_state *st = ad_sigma_delta_to_ad7780(sigma_delta);
113 if ((raw_sample & AD7780_ERR) ||
114 !((raw_sample & AD7780_PAT0) && !(raw_sample & AD7780_PAT1)))
117 if (raw_sample & AD7780_GAIN)
125 static const struct ad_sigma_delta_info ad7780_sigma_delta_info = {
126 .set_mode = ad7780_set_mode,
127 .postprocess_sample = ad7780_postprocess_sample,
128 .has_registers = false,
131 static const struct ad7780_chip_info ad7780_chip_info_tbl[] = {
133 .channel = AD_SD_CHANNEL(1, 0, 0, 24, 32, 8),
136 .channel = AD_SD_CHANNEL(1, 0, 0, 20, 32, 12),
140 static const struct iio_info ad7780_info = {
141 .read_raw = &ad7780_read_raw,
142 .driver_module = THIS_MODULE,
145 static int __devinit ad7780_probe(struct spi_device *spi)
147 struct ad7780_platform_data *pdata = spi->dev.platform_data;
148 struct ad7780_state *st;
149 struct iio_dev *indio_dev;
150 int ret, voltage_uv = 0;
152 indio_dev = iio_device_alloc(sizeof(*st));
153 if (indio_dev == NULL)
156 st = iio_priv(indio_dev);
159 ad_sd_init(&st->sd, indio_dev, spi, &ad7780_sigma_delta_info);
161 st->reg = regulator_get(&spi->dev, "vcc");
162 if (!IS_ERR(st->reg)) {
163 ret = regulator_enable(st->reg);
167 voltage_uv = regulator_get_voltage(st->reg);
171 &ad7780_chip_info_tbl[spi_get_device_id(spi)->driver_data];
173 if (pdata && pdata->vref_mv)
174 st->int_vref_mv = pdata->vref_mv;
176 st->int_vref_mv = voltage_uv / 1000;
178 dev_warn(&spi->dev, "reference voltage unspecified\n");
180 spi_set_drvdata(spi, indio_dev);
182 indio_dev->dev.parent = &spi->dev;
183 indio_dev->name = spi_get_device_id(spi)->name;
184 indio_dev->modes = INDIO_DIRECT_MODE;
185 indio_dev->channels = &st->chip_info->channel;
186 indio_dev->num_channels = 1;
187 indio_dev->info = &ad7780_info;
189 if (pdata && gpio_is_valid(pdata->gpio_pdrst)) {
191 ret = gpio_request_one(pdata->gpio_pdrst, GPIOF_OUT_INIT_LOW,
194 dev_err(&spi->dev, "failed to request GPIO PDRST\n");
195 goto error_disable_reg;
197 st->powerdown_gpio = pdata->gpio_pdrst;
199 st->powerdown_gpio = -1;
202 ret = ad_sd_setup_buffer_and_trigger(indio_dev);
204 goto error_free_gpio;
206 ret = iio_device_register(indio_dev);
208 goto error_cleanup_buffer_and_trigger;
212 error_cleanup_buffer_and_trigger:
213 ad_sd_cleanup_buffer_and_trigger(indio_dev);
215 if (pdata && gpio_is_valid(pdata->gpio_pdrst))
216 gpio_free(pdata->gpio_pdrst);
218 if (!IS_ERR(st->reg))
219 regulator_disable(st->reg);
221 if (!IS_ERR(st->reg))
222 regulator_put(st->reg);
224 iio_device_free(indio_dev);
229 static int __devexit ad7780_remove(struct spi_device *spi)
231 struct iio_dev *indio_dev = spi_get_drvdata(spi);
232 struct ad7780_state *st = iio_priv(indio_dev);
234 iio_device_unregister(indio_dev);
235 ad_sd_cleanup_buffer_and_trigger(indio_dev);
237 if (gpio_is_valid(st->powerdown_gpio))
238 gpio_free(st->powerdown_gpio);
240 if (!IS_ERR(st->reg)) {
241 regulator_disable(st->reg);
242 regulator_put(st->reg);
244 iio_device_free(indio_dev);
249 static const struct spi_device_id ad7780_id[] = {
250 {"ad7780", ID_AD7780},
251 {"ad7781", ID_AD7781},
254 MODULE_DEVICE_TABLE(spi, ad7780_id);
256 static struct spi_driver ad7780_driver = {
259 .owner = THIS_MODULE,
261 .probe = ad7780_probe,
262 .remove = __devexit_p(ad7780_remove),
263 .id_table = ad7780_id,
265 module_spi_driver(ad7780_driver);
267 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
268 MODULE_DESCRIPTION("Analog Devices AD7780/1 ADC");
269 MODULE_LICENSE("GPL v2");