From 9085daa4abcc3a1c19ae4eb00e609842ef28275a Mon Sep 17 00:00:00 2001 From: Renato Lui Geh Date: Fri, 15 Mar 2019 23:12:27 -0300 Subject: [PATCH] staging: iio: ad7780: add gain & filter gpio support Previously, the AD7780 driver only supported gpio for the 'powerdown' pin. This commit adds suppport for the 'gain' and 'filter' pin. Signed-off-by: Renato Lui Geh Signed-off-by: Giuliano Belinassi Co-developed-by: Giuliano Belinassi Signed-off-by: Jonathan Cameron --- drivers/staging/iio/adc/ad7780.c | 114 ++++++++++++++++++++++++++----- 1 file changed, 96 insertions(+), 18 deletions(-) diff --git a/drivers/staging/iio/adc/ad7780.c b/drivers/staging/iio/adc/ad7780.c index c4a85789c2db..a7e004228e57 100644 --- a/drivers/staging/iio/adc/ad7780.c +++ b/drivers/staging/iio/adc/ad7780.c @@ -39,6 +39,9 @@ #define AD7170_PATTERN (AD7780_PAT0 | AD7170_PAT2) #define AD7170_PATTERN_MASK (AD7780_PAT0 | AD7780_PAT1 | AD7170_PAT2) +#define AD7780_GAIN_MIDPOINT 64 +#define AD7780_FILTER_MIDPOINT 13350 + struct ad7780_chip_info { struct iio_chan_spec channel; unsigned int pattern_mask; @@ -50,7 +53,10 @@ struct ad7780_state { const struct ad7780_chip_info *chip_info; struct regulator *reg; struct gpio_desc *powerdown_gpio; - unsigned int gain; + struct gpio_desc *gain_gpio; + struct gpio_desc *filter_gpio; + unsigned int gain; + unsigned int int_vref_mv; struct ad_sigma_delta sd; }; @@ -104,8 +110,10 @@ static int ad7780_read_raw(struct iio_dev *indio_dev, voltage_uv = regulator_get_voltage(st->reg); if (voltage_uv < 0) return voltage_uv; - *val = (voltage_uv / 1000) * st->gain; + voltage_uv /= 1000; + *val = voltage_uv * st->gain; *val2 = chan->scan_type.realbits - 1; + st->int_vref_mv = voltage_uv; return IIO_VAL_FRACTIONAL_LOG2; case IIO_CHAN_INFO_OFFSET: *val = -(1 << (chan->scan_type.realbits - 1)); @@ -115,6 +123,50 @@ static int ad7780_read_raw(struct iio_dev *indio_dev, return -EINVAL; } +static int ad7780_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, + int val2, + long m) +{ + struct ad7780_state *st = iio_priv(indio_dev); + const struct ad7780_chip_info *chip_info = st->chip_info; + unsigned long long vref; + unsigned int full_scale, gain; + + if (!chip_info->is_ad778x) + return -EINVAL; + + switch (m) { + case IIO_CHAN_INFO_SCALE: + if (val != 0) + return -EINVAL; + + vref = st->int_vref_mv * 1000000LL; + full_scale = 1 << (chip_info->channel.scan_type.realbits - 1); + gain = DIV_ROUND_CLOSEST_ULL(vref, full_scale); + gain = DIV_ROUND_CLOSEST(gain, val2); + st->gain = gain; + if (gain < AD7780_GAIN_MIDPOINT) + gain = 0; + else + gain = 1; + gpiod_set_value(st->gain_gpio, gain); + break; + case IIO_CHAN_INFO_SAMP_FREQ: + if (1000*val + val2/1000 < AD7780_FILTER_MIDPOINT) + val = 0; + else + val = 1; + gpiod_set_value(st->filter_gpio, val); + break; + default: + break; + } + + return 0; +} + static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta, unsigned int raw_sample) { @@ -125,13 +177,6 @@ static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta, ((raw_sample & chip_info->pattern_mask) != chip_info->pattern)) return -EIO; - if (chip_info->is_ad778x) { - if (raw_sample & AD7780_GAIN) - st->gain = 1; - else - st->gain = 128; - } - return 0; } @@ -173,8 +218,47 @@ static const struct ad7780_chip_info ad7780_chip_info_tbl[] = { static const struct iio_info ad7780_info = { .read_raw = ad7780_read_raw, + .write_raw = ad7780_write_raw, }; +static int ad7780_init_gpios(struct device *dev, struct ad7780_state *st) +{ + int ret; + + st->powerdown_gpio = devm_gpiod_get_optional(dev, + "powerdown", + GPIOD_OUT_LOW); + if (IS_ERR(st->powerdown_gpio)) { + ret = PTR_ERR(st->powerdown_gpio); + dev_err(dev, "Failed to request powerdown GPIO: %d\n", ret); + return ret; + } + + if (!st->chip_info->is_ad778x) + return 0; + + + st->gain_gpio = devm_gpiod_get_optional(dev, + "adi,gain", + GPIOD_OUT_HIGH); + if (IS_ERR(st->gain_gpio)) { + ret = PTR_ERR(st->gain_gpio); + dev_err(dev, "Failed to request gain GPIO: %d\n", ret); + return ret; + } + + st->filter_gpio = devm_gpiod_get_optional(dev, + "adi,filter", + GPIOD_OUT_HIGH); + if (IS_ERR(st->filter_gpio)) { + ret = PTR_ERR(st->filter_gpio); + dev_err(dev, "Failed to request filter GPIO: %d\n", ret); + return ret; + } + + return 0; +} + static int ad7780_probe(struct spi_device *spi) { struct ad7780_state *st; @@ -212,15 +296,9 @@ static int ad7780_probe(struct spi_device *spi) indio_dev->num_channels = 1; indio_dev->info = &ad7780_info; - st->powerdown_gpio = devm_gpiod_get_optional(&spi->dev, - "powerdown", - GPIOD_OUT_LOW); - if (IS_ERR(st->powerdown_gpio)) { - ret = PTR_ERR(st->powerdown_gpio); - dev_err(&spi->dev, "Failed to request powerdown GPIO: %d\n", - ret); - goto error_disable_reg; - } + ret = ad7780_init_gpios(&spi->dev, st); + if (ret) + goto error_cleanup_buffer_and_trigger; ret = ad_sd_setup_buffer_and_trigger(indio_dev); if (ret)