From 42776c14c69224a75c781852ae4ca9a4811fd075 Mon Sep 17 00:00:00 2001 From: Mircea Caprioru Date: Mon, 2 Sep 2019 16:08:30 +0300 Subject: [PATCH] staging: iio: adc: ad7192: Add system calibration support This patch will add a system calibration attribute for each channel. Using this option the user will have the ability to calibrate each channel for zero scale and full scale. It uses the iio_chan_spec_ext_info and IIO_ENUM to implement the functionality. Signed-off-by: Mircea Caprioru Signed-off-by: Jonathan Cameron --- .../ABI/testing/sysfs-bus-iio-adc-ad7192 | 24 ++++++ drivers/staging/iio/adc/ad7192.c | 79 ++++++++++++++++++- 2 files changed, 102 insertions(+), 1 deletion(-) diff --git a/Documentation/ABI/testing/sysfs-bus-iio-adc-ad7192 b/Documentation/ABI/testing/sysfs-bus-iio-adc-ad7192 index 74a2873045bf..7627d3be08f5 100644 --- a/Documentation/ABI/testing/sysfs-bus-iio-adc-ad7192 +++ b/Documentation/ABI/testing/sysfs-bus-iio-adc-ad7192 @@ -13,3 +13,27 @@ Description: need to minimize the system current consumption. Reading gives the state of the bridge switch. Writing '1' enables the bridge switch. + +What: /sys/bus/iio/devices/iio:deviceX/in_voltagex_sys_calibration +KernelVersion: +Contact: linux-iio@vger.kernel.org +Description: + Initiates the system calibration procedure. This is done on a + single channel at a time. Write '1' to start the calibration. + +What: /sys/bus/iio/devices/iio:deviceX/in_voltagex_sys_calibration_mode_available +KernelVersion: +Contact: linux-iio@vger.kernel.org +Description: + Reading returns a list with the possible calibration modes. + There are two available options: + "zero_scale" - calibrate to zero scale + "full_scale" - calibrate to full scale + +What: /sys/bus/iio/devices/iio:deviceX/in_voltagex_sys_calibration_mode +KernelVersion: +Contact: linux-iio@vger.kernel.org +Description: + Sets up the calibration mode used in the system calibration + procedure. Reading returns the current calibration mode. + Writing sets the system calibration mode. diff --git a/drivers/staging/iio/adc/ad7192.c b/drivers/staging/iio/adc/ad7192.c index e6b660489165..bf3e2a9cc07f 100644 --- a/drivers/staging/iio/adc/ad7192.c +++ b/drivers/staging/iio/adc/ad7192.c @@ -155,6 +155,11 @@ * The DOUT/RDY output must also be wired to an interrupt capable GPIO. */ +enum { + AD7192_SYSCALIB_ZERO_SCALE, + AD7192_SYSCALIB_FULL_SCALE, +}; + struct ad7192_state { struct regulator *avdd; struct regulator *dvdd; @@ -169,10 +174,80 @@ struct ad7192_state { u8 devid; u8 clock_sel; struct mutex lock; /* protect sensor state */ + u8 syscalib_mode[8]; struct ad_sigma_delta sd; }; +static const char * const ad7192_syscalib_modes[] = { + [AD7192_SYSCALIB_ZERO_SCALE] = "zero_scale", + [AD7192_SYSCALIB_FULL_SCALE] = "full_scale", +}; + +static int ad7192_set_syscalib_mode(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + unsigned int mode) +{ + struct ad7192_state *st = iio_priv(indio_dev); + + st->syscalib_mode[chan->channel] = mode; + + return 0; +} + +static int ad7192_get_syscalib_mode(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan) +{ + struct ad7192_state *st = iio_priv(indio_dev); + + return st->syscalib_mode[chan->channel]; +} + +static ssize_t ad7192_write_syscalib(struct iio_dev *indio_dev, + uintptr_t private, + const struct iio_chan_spec *chan, + const char *buf, size_t len) +{ + struct ad7192_state *st = iio_priv(indio_dev); + bool sys_calib; + int ret, temp; + + ret = strtobool(buf, &sys_calib); + if (ret) + return ret; + + temp = st->syscalib_mode[chan->channel]; + if (sys_calib) { + if (temp == AD7192_SYSCALIB_ZERO_SCALE) + ret = ad_sd_calibrate(&st->sd, AD7192_MODE_CAL_SYS_ZERO, + chan->address); + else + ret = ad_sd_calibrate(&st->sd, AD7192_MODE_CAL_SYS_FULL, + chan->address); + } + + return ret ? ret : len; +} + +static const struct iio_enum ad7192_syscalib_mode_enum = { + .items = ad7192_syscalib_modes, + .num_items = ARRAY_SIZE(ad7192_syscalib_modes), + .set = ad7192_set_syscalib_mode, + .get = ad7192_get_syscalib_mode +}; + +static const struct iio_chan_spec_ext_info ad7192_calibsys_ext_info[] = { + { + .name = "sys_calibration", + .write = ad7192_write_syscalib, + .shared = IIO_SEPARATE, + }, + IIO_ENUM("sys_calibration_mode", IIO_SEPARATE, + &ad7192_syscalib_mode_enum), + IIO_ENUM_AVAILABLE("sys_calibration_mode", &ad7192_syscalib_mode_enum), + {} +}; + static struct ad7192_state *ad_sigma_delta_to_ad7192(struct ad_sigma_delta *sd) { return container_of(sd, struct ad7192_state, sd); @@ -770,9 +845,11 @@ static int ad7192_channels_config(struct iio_dev *indio_dev) *chan = channels[i]; chan->info_mask_shared_by_all |= BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY); - if (chan->type != IIO_TEMP) + if (chan->type != IIO_TEMP) { chan->info_mask_shared_by_type_available |= BIT(IIO_CHAN_INFO_SCALE); + chan->ext_info = ad7192_calibsys_ext_info; + } chan++; }