From: Dumitru Ceclan <dumitru.ceclan@xxxxxxxxxx> Sigma delta ADCs with a sequencer need to disable the previously enabled channel when reading using ad_sigma_delta_single_conversion(). This was done manually in drivers for devices with sequencers. This patch implements handling of single channel disabling after a single conversion. Signed-off-by: Dumitru Ceclan <dumitru.ceclan@xxxxxxxxxx> --- drivers/iio/adc/ad7124.c | 14 ++++++++------ drivers/iio/adc/ad7173.c | 11 ++++++----- drivers/iio/adc/ad_sigma_delta.c | 6 ++++++ include/linux/iio/adc/ad_sigma_delta.h | 14 ++++++++++++++ 4 files changed, 34 insertions(+), 11 deletions(-) diff --git a/drivers/iio/adc/ad7124.c b/drivers/iio/adc/ad7124.c index e7b1d517d3de..3beed78496c5 100644 --- a/drivers/iio/adc/ad7124.c +++ b/drivers/iio/adc/ad7124.c @@ -555,10 +555,18 @@ static int ad7124_disable_all(struct ad_sigma_delta *sd) return 0; } +static int ad7124_disable_one(struct ad_sigma_delta *sd, unsigned int chan) +{ + struct ad7124_state *st = container_of(sd, struct ad7124_state, sd); + + return ad7124_spi_write_mask(st, AD7124_CHANNEL(chan), AD7124_CHANNEL_EN_MSK, 0, 2); +} + static const struct ad_sigma_delta_info ad7124_sigma_delta_info = { .set_channel = ad7124_set_channel, .append_status = ad7124_append_status, .disable_all = ad7124_disable_all, + .disable_one = ad7124_disable_one, .set_mode = ad7124_set_mode, .has_registers = true, .addr_shift = 0, @@ -582,12 +590,6 @@ static int ad7124_read_raw(struct iio_dev *indio_dev, if (ret < 0) return ret; - /* After the conversion is performed, disable the channel */ - ret = ad_sd_write_reg(&st->sd, AD7124_CHANNEL(chan->address), 2, - st->channels[chan->address].ain | AD7124_CHANNEL_EN(0)); - if (ret < 0) - return ret; - return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: mutex_lock(&st->cfgs_lock); diff --git a/drivers/iio/adc/ad7173.c b/drivers/iio/adc/ad7173.c index 638e2468efbf..f3088e8b4b8b 100644 --- a/drivers/iio/adc/ad7173.c +++ b/drivers/iio/adc/ad7173.c @@ -569,10 +569,16 @@ static int ad7173_disable_all(struct ad_sigma_delta *sd) return 0; } +static int ad7173_disable_one(struct ad_sigma_delta *sd, unsigned int chan) +{ + return ad_sd_write_reg(sd, AD7173_REG_CH(chan), 2, 0); +} + static struct ad_sigma_delta_info ad7173_sigma_delta_info = { .set_channel = ad7173_set_channel, .append_status = ad7173_append_status, .disable_all = ad7173_disable_all, + .disable_one = ad7173_disable_one, .set_mode = ad7173_set_mode, .has_registers = true, .addr_shift = 0, @@ -668,11 +674,6 @@ static int ad7173_read_raw(struct iio_dev *indio_dev, if (ret < 0) return ret; - /* disable channel after single conversion */ - ret = ad_sd_write_reg(&st->sd, AD7173_REG_CH(chan->address), 2, 0); - if (ret < 0) - return ret; - return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: if (chan->type == IIO_TEMP) { diff --git a/drivers/iio/adc/ad_sigma_delta.c b/drivers/iio/adc/ad_sigma_delta.c index 97a05f325df7..ec34b3d1336f 100644 --- a/drivers/iio/adc/ad_sigma_delta.c +++ b/drivers/iio/adc/ad_sigma_delta.c @@ -321,6 +321,7 @@ int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev, sigma_delta->keep_cs_asserted = false; ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE); + ad_sigma_delta_disable_one(sigma_delta, chan->address); sigma_delta->bus_locked = false; spi_bus_unlock(sigma_delta->spi->controller); iio_device_release_direct_mode(indio_dev); @@ -671,6 +672,11 @@ int ad_sd_init(struct ad_sigma_delta *sigma_delta, struct iio_dev *indio_dev, dev_err(&spi->dev, "ad_sigma_delta_info lacks disable_all().\n"); return -EINVAL; } + + if (!info->disable_one) { + dev_err(&spi->dev, "ad_sigma_delta_info lacks disable_one().\n"); + return -EINVAL; + } } if (info->irq_line) diff --git a/include/linux/iio/adc/ad_sigma_delta.h b/include/linux/iio/adc/ad_sigma_delta.h index 383614ebd760..f8c1d2505940 100644 --- a/include/linux/iio/adc/ad_sigma_delta.h +++ b/include/linux/iio/adc/ad_sigma_delta.h @@ -37,6 +37,10 @@ struct iio_dev; * @append_status: Will be called to enable status append at the end of the sample, may be NULL. * @set_mode: Will be called to select the current mode, may be NULL. * @disable_all: Will be called to disable all channels, may be NULL. + * @disable_one: Will be called to disable a single channel after + * ad_sigma_delta_single_conversion(), may be NULL. + * Usage of this callback expects iio_chan_spec.address to contain + * the value required for the driver to identify the channel. * @postprocess_sample: Is called for each sampled data word, can be used to * modify or drop the sample data, it, may be NULL. * @has_registers: true if the device has writable and readable registers, false @@ -55,6 +59,7 @@ struct ad_sigma_delta_info { int (*append_status)(struct ad_sigma_delta *, bool append); int (*set_mode)(struct ad_sigma_delta *, enum ad_sigma_delta_mode mode); int (*disable_all)(struct ad_sigma_delta *); + int (*disable_one)(struct ad_sigma_delta *, unsigned int chan); int (*postprocess_sample)(struct ad_sigma_delta *, unsigned int raw_sample); bool has_registers; unsigned int addr_shift; @@ -140,6 +145,15 @@ static inline int ad_sigma_delta_disable_all(struct ad_sigma_delta *sd) return 0; } +static inline int ad_sigma_delta_disable_one(struct ad_sigma_delta *sd, + unsigned int chan) +{ + if (sd->info->disable_one) + return sd->info->disable_one(sd, chan); + + return 0; +} + static inline int ad_sigma_delta_set_mode(struct ad_sigma_delta *sd, unsigned int mode) { -- 2.43.0