diff options
Diffstat (limited to 'kernel/drivers/iio/adc/ad7791.c')
| -rw-r--r-- | kernel/drivers/iio/adc/ad7791.c | 453 |
1 files changed, 453 insertions, 0 deletions
diff --git a/kernel/drivers/iio/adc/ad7791.c b/kernel/drivers/iio/adc/ad7791.c new file mode 100644 index 000000000..c19f8fd1b --- /dev/null +++ b/kernel/drivers/iio/adc/ad7791.c @@ -0,0 +1,453 @@ +/* + * AD7787/AD7788/AD7789/AD7790/AD7791 SPI ADC driver + * + * Copyright 2012 Analog Devices Inc. + * Author: Lars-Peter Clausen <lars@metafoo.de> + * + * Licensed under the GPL-2. + */ + +#include <linux/interrupt.h> +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/sysfs.h> +#include <linux/spi/spi.h> +#include <linux/regulator/consumer.h> +#include <linux/err.h> +#include <linux/sched.h> +#include <linux/delay.h> +#include <linux/module.h> + +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/iio/buffer.h> +#include <linux/iio/trigger.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/triggered_buffer.h> +#include <linux/iio/adc/ad_sigma_delta.h> + +#include <linux/platform_data/ad7791.h> + +#define AD7791_REG_COMM 0x0 /* For writes */ +#define AD7791_REG_STATUS 0x0 /* For reads */ +#define AD7791_REG_MODE 0x1 +#define AD7791_REG_FILTER 0x2 +#define AD7791_REG_DATA 0x3 + +#define AD7791_MODE_CONTINUOUS 0x00 +#define AD7791_MODE_SINGLE 0x02 +#define AD7791_MODE_POWERDOWN 0x03 + +#define AD7791_CH_AIN1P_AIN1N 0x00 +#define AD7791_CH_AIN2 0x01 +#define AD7791_CH_AIN1N_AIN1N 0x02 +#define AD7791_CH_AVDD_MONITOR 0x03 + +#define AD7791_FILTER_CLK_DIV_1 (0x0 << 4) +#define AD7791_FILTER_CLK_DIV_2 (0x1 << 4) +#define AD7791_FILTER_CLK_DIV_4 (0x2 << 4) +#define AD7791_FILTER_CLK_DIV_8 (0x3 << 4) +#define AD7791_FILTER_CLK_MASK (0x3 << 4) +#define AD7791_FILTER_RATE_120 0x0 +#define AD7791_FILTER_RATE_100 0x1 +#define AD7791_FILTER_RATE_33_3 0x2 +#define AD7791_FILTER_RATE_20 0x3 +#define AD7791_FILTER_RATE_16_6 0x4 +#define AD7791_FILTER_RATE_16_7 0x5 +#define AD7791_FILTER_RATE_13_3 0x6 +#define AD7791_FILTER_RATE_9_5 0x7 +#define AD7791_FILTER_RATE_MASK 0x7 + +#define AD7791_MODE_BUFFER BIT(1) +#define AD7791_MODE_UNIPOLAR BIT(2) +#define AD7791_MODE_BURNOUT BIT(3) +#define AD7791_MODE_SEL_MASK (0x3 << 6) +#define AD7791_MODE_SEL(x) ((x) << 6) + +#define DECLARE_AD7787_CHANNELS(name, bits, storagebits) \ +const struct iio_chan_spec name[] = { \ + AD_SD_DIFF_CHANNEL(0, 0, 0, AD7791_CH_AIN1P_AIN1N, \ + (bits), (storagebits), 0), \ + AD_SD_CHANNEL(1, 1, AD7791_CH_AIN2, (bits), (storagebits), 0), \ + AD_SD_SHORTED_CHANNEL(2, 0, AD7791_CH_AIN1N_AIN1N, \ + (bits), (storagebits), 0), \ + AD_SD_SUPPLY_CHANNEL(3, 2, AD7791_CH_AVDD_MONITOR, \ + (bits), (storagebits), 0), \ + IIO_CHAN_SOFT_TIMESTAMP(4), \ +} + +#define DECLARE_AD7791_CHANNELS(name, bits, storagebits) \ +const struct iio_chan_spec name[] = { \ + AD_SD_DIFF_CHANNEL(0, 0, 0, AD7791_CH_AIN1P_AIN1N, \ + (bits), (storagebits), 0), \ + AD_SD_SHORTED_CHANNEL(1, 0, AD7791_CH_AIN1N_AIN1N, \ + (bits), (storagebits), 0), \ + AD_SD_SUPPLY_CHANNEL(2, 1, AD7791_CH_AVDD_MONITOR, \ + (bits), (storagebits), 0), \ + IIO_CHAN_SOFT_TIMESTAMP(3), \ +} + +static DECLARE_AD7787_CHANNELS(ad7787_channels, 24, 32); +static DECLARE_AD7791_CHANNELS(ad7790_channels, 16, 16); +static DECLARE_AD7791_CHANNELS(ad7791_channels, 24, 32); + +enum { + AD7787, + AD7788, + AD7789, + AD7790, + AD7791, +}; + +enum ad7791_chip_info_flags { + AD7791_FLAG_HAS_FILTER = (1 << 0), + AD7791_FLAG_HAS_BUFFER = (1 << 1), + AD7791_FLAG_HAS_UNIPOLAR = (1 << 2), + AD7791_FLAG_HAS_BURNOUT = (1 << 3), +}; + +struct ad7791_chip_info { + const struct iio_chan_spec *channels; + unsigned int num_channels; + enum ad7791_chip_info_flags flags; +}; + +static const struct ad7791_chip_info ad7791_chip_infos[] = { + [AD7787] = { + .channels = ad7787_channels, + .num_channels = ARRAY_SIZE(ad7787_channels), + .flags = AD7791_FLAG_HAS_FILTER | AD7791_FLAG_HAS_BUFFER | + AD7791_FLAG_HAS_UNIPOLAR | AD7791_FLAG_HAS_BURNOUT, + }, + [AD7788] = { + .channels = ad7790_channels, + .num_channels = ARRAY_SIZE(ad7790_channels), + .flags = AD7791_FLAG_HAS_UNIPOLAR, + }, + [AD7789] = { + .channels = ad7791_channels, + .num_channels = ARRAY_SIZE(ad7791_channels), + .flags = AD7791_FLAG_HAS_UNIPOLAR, + }, + [AD7790] = { + .channels = ad7790_channels, + .num_channels = ARRAY_SIZE(ad7790_channels), + .flags = AD7791_FLAG_HAS_FILTER | AD7791_FLAG_HAS_BUFFER | + AD7791_FLAG_HAS_BURNOUT, + }, + [AD7791] = { + .channels = ad7791_channels, + .num_channels = ARRAY_SIZE(ad7791_channels), + .flags = AD7791_FLAG_HAS_FILTER | AD7791_FLAG_HAS_BUFFER | + AD7791_FLAG_HAS_UNIPOLAR | AD7791_FLAG_HAS_BURNOUT, + }, +}; + +struct ad7791_state { + struct ad_sigma_delta sd; + uint8_t mode; + uint8_t filter; + + struct regulator *reg; + const struct ad7791_chip_info *info; +}; + +static struct ad7791_state *ad_sigma_delta_to_ad7791(struct ad_sigma_delta *sd) +{ + return container_of(sd, struct ad7791_state, sd); +} + +static int ad7791_set_channel(struct ad_sigma_delta *sd, unsigned int channel) +{ + ad_sd_set_comm(sd, channel); + + return 0; +} + +static int ad7791_set_mode(struct ad_sigma_delta *sd, + enum ad_sigma_delta_mode mode) +{ + struct ad7791_state *st = ad_sigma_delta_to_ad7791(sd); + + switch (mode) { + case AD_SD_MODE_CONTINUOUS: + mode = AD7791_MODE_CONTINUOUS; + break; + case AD_SD_MODE_SINGLE: + mode = AD7791_MODE_SINGLE; + break; + case AD_SD_MODE_IDLE: + case AD_SD_MODE_POWERDOWN: + mode = AD7791_MODE_POWERDOWN; + break; + } + + st->mode &= ~AD7791_MODE_SEL_MASK; + st->mode |= AD7791_MODE_SEL(mode); + + return ad_sd_write_reg(sd, AD7791_REG_MODE, sizeof(st->mode), st->mode); +} + +static const struct ad_sigma_delta_info ad7791_sigma_delta_info = { + .set_channel = ad7791_set_channel, + .set_mode = ad7791_set_mode, + .has_registers = true, + .addr_shift = 4, + .read_mask = BIT(3), +}; + +static int ad7791_read_raw(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, int *val, int *val2, long info) +{ + struct ad7791_state *st = iio_priv(indio_dev); + bool unipolar = !!(st->mode & AD7791_MODE_UNIPOLAR); + + switch (info) { + case IIO_CHAN_INFO_RAW: + return ad_sigma_delta_single_conversion(indio_dev, chan, val); + case IIO_CHAN_INFO_OFFSET: + /** + * Unipolar: 0 to VREF + * Bipolar -VREF to VREF + **/ + if (unipolar) + *val = 0; + else + *val = -(1 << (chan->scan_type.realbits - 1)); + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + /* The monitor channel uses an internal reference. */ + if (chan->address == AD7791_CH_AVDD_MONITOR) { + /* + * The signal is attenuated by a factor of 5 and + * compared against a 1.17V internal reference. + */ + *val = 1170 * 5; + } else { + int voltage_uv; + + voltage_uv = regulator_get_voltage(st->reg); + if (voltage_uv < 0) + return voltage_uv; + + *val = voltage_uv / 1000; + } + if (unipolar) + *val2 = chan->scan_type.realbits; + else + *val2 = chan->scan_type.realbits - 1; + + return IIO_VAL_FRACTIONAL_LOG2; + } + + return -EINVAL; +} + +static const char * const ad7791_sample_freq_avail[] = { + [AD7791_FILTER_RATE_120] = "120", + [AD7791_FILTER_RATE_100] = "100", + [AD7791_FILTER_RATE_33_3] = "33.3", + [AD7791_FILTER_RATE_20] = "20", + [AD7791_FILTER_RATE_16_6] = "16.6", + [AD7791_FILTER_RATE_16_7] = "16.7", + [AD7791_FILTER_RATE_13_3] = "13.3", + [AD7791_FILTER_RATE_9_5] = "9.5", +}; + +static ssize_t ad7791_read_frequency(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct iio_dev *indio_dev = dev_to_iio_dev(dev); + struct ad7791_state *st = iio_priv(indio_dev); + unsigned int rate = st->filter & AD7791_FILTER_RATE_MASK; + + return sprintf(buf, "%s\n", ad7791_sample_freq_avail[rate]); +} + +static ssize_t ad7791_write_frequency(struct device *dev, + struct device_attribute *attr, const char *buf, size_t len) +{ + struct iio_dev *indio_dev = dev_to_iio_dev(dev); + struct ad7791_state *st = iio_priv(indio_dev); + int i, ret; + + mutex_lock(&indio_dev->mlock); + if (iio_buffer_enabled(indio_dev)) { + mutex_unlock(&indio_dev->mlock); + return -EBUSY; + } + mutex_unlock(&indio_dev->mlock); + + ret = -EINVAL; + + for (i = 0; i < ARRAY_SIZE(ad7791_sample_freq_avail); i++) { + if (sysfs_streq(ad7791_sample_freq_avail[i], buf)) { + + mutex_lock(&indio_dev->mlock); + st->filter &= ~AD7791_FILTER_RATE_MASK; + st->filter |= i; + ad_sd_write_reg(&st->sd, AD7791_REG_FILTER, + sizeof(st->filter), st->filter); + mutex_unlock(&indio_dev->mlock); + ret = 0; + break; + } + } + + return ret ? ret : len; +} + +static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO, + ad7791_read_frequency, + ad7791_write_frequency); + +static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("120 100 33.3 20 16.7 16.6 13.3 9.5"); + +static struct attribute *ad7791_attributes[] = { + &iio_dev_attr_sampling_frequency.dev_attr.attr, + &iio_const_attr_sampling_frequency_available.dev_attr.attr, + NULL +}; + +static const struct attribute_group ad7791_attribute_group = { + .attrs = ad7791_attributes, +}; + +static const struct iio_info ad7791_info = { + .read_raw = &ad7791_read_raw, + .attrs = &ad7791_attribute_group, + .validate_trigger = ad_sd_validate_trigger, + .driver_module = THIS_MODULE, +}; + +static const struct iio_info ad7791_no_filter_info = { + .read_raw = &ad7791_read_raw, + .validate_trigger = ad_sd_validate_trigger, + .driver_module = THIS_MODULE, +}; + +static int ad7791_setup(struct ad7791_state *st, + struct ad7791_platform_data *pdata) +{ + /* Set to poweron-reset default values */ + st->mode = AD7791_MODE_BUFFER; + st->filter = AD7791_FILTER_RATE_16_6; + + if (!pdata) + return 0; + + if ((st->info->flags & AD7791_FLAG_HAS_BUFFER) && !pdata->buffered) + st->mode &= ~AD7791_MODE_BUFFER; + + if ((st->info->flags & AD7791_FLAG_HAS_BURNOUT) && + pdata->burnout_current) + st->mode |= AD7791_MODE_BURNOUT; + + if ((st->info->flags & AD7791_FLAG_HAS_UNIPOLAR) && pdata->unipolar) + st->mode |= AD7791_MODE_UNIPOLAR; + + return ad_sd_write_reg(&st->sd, AD7791_REG_MODE, sizeof(st->mode), + st->mode); +} + +static int ad7791_probe(struct spi_device *spi) +{ + struct ad7791_platform_data *pdata = spi->dev.platform_data; + struct iio_dev *indio_dev; + struct ad7791_state *st; + int ret; + + if (!spi->irq) { + dev_err(&spi->dev, "Missing IRQ.\n"); + return -ENXIO; + } + + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); + if (!indio_dev) + return -ENOMEM; + + st = iio_priv(indio_dev); + + st->reg = devm_regulator_get(&spi->dev, "refin"); + if (IS_ERR(st->reg)) + return PTR_ERR(st->reg); + + ret = regulator_enable(st->reg); + if (ret) + return ret; + + st->info = &ad7791_chip_infos[spi_get_device_id(spi)->driver_data]; + ad_sd_init(&st->sd, indio_dev, spi, &ad7791_sigma_delta_info); + + spi_set_drvdata(spi, indio_dev); + + indio_dev->dev.parent = &spi->dev; + indio_dev->name = spi_get_device_id(spi)->name; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = st->info->channels; + indio_dev->num_channels = st->info->num_channels; + if (st->info->flags & AD7791_FLAG_HAS_FILTER) + indio_dev->info = &ad7791_info; + else + indio_dev->info = &ad7791_no_filter_info; + + ret = ad_sd_setup_buffer_and_trigger(indio_dev); + if (ret) + goto error_disable_reg; + + ret = ad7791_setup(st, pdata); + if (ret) + goto error_remove_trigger; + + ret = iio_device_register(indio_dev); + if (ret) + goto error_remove_trigger; + + return 0; + +error_remove_trigger: + ad_sd_cleanup_buffer_and_trigger(indio_dev); +error_disable_reg: + regulator_disable(st->reg); + + return ret; +} + +static int ad7791_remove(struct spi_device *spi) +{ + struct iio_dev *indio_dev = spi_get_drvdata(spi); + struct ad7791_state *st = iio_priv(indio_dev); + + iio_device_unregister(indio_dev); + ad_sd_cleanup_buffer_and_trigger(indio_dev); + + regulator_disable(st->reg); + + return 0; +} + +static const struct spi_device_id ad7791_spi_ids[] = { + { "ad7787", AD7787 }, + { "ad7788", AD7788 }, + { "ad7789", AD7789 }, + { "ad7790", AD7790 }, + { "ad7791", AD7791 }, + {} +}; +MODULE_DEVICE_TABLE(spi, ad7791_spi_ids); + +static struct spi_driver ad7791_driver = { + .driver = { + .name = "ad7791", + .owner = THIS_MODULE, + }, + .probe = ad7791_probe, + .remove = ad7791_remove, + .id_table = ad7791_spi_ids, +}; +module_spi_driver(ad7791_driver); + +MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); +MODULE_DESCRIPTION("Analog Device AD7787/AD7788/AD7789/AD7790/AD7791 ADC driver"); +MODULE_LICENSE("GPL v2"); |