Re: [PATCH 04/11] staging: iio: tsl2x7x: simplify tsl2x7x_prox_cal()

From: Jonathan Cameron
Date: Sat Mar 24 2018 - 09:35:43 EST


On Wed, 21 Mar 2018 06:29:05 -0400
Brian Masney <masneyb@xxxxxxxxxxxxx> wrote:

> tsl2x7x_prox_cal() would set the interrupt flag, and reset the device to
> start doing the calibration routine. However, this did not actually
> affect the readings since they are polled. This patch drops the interrupt
> code.
>
> This patch also drops the function tsl2x7x_prox_calculate() and removes
> support for the standard deviation and min sample since those values
> were not used.
>
> Driver was tested using a TSL2772 hooked up to a Raspberry Pi 2. I
> performed the following testing at various distances:
>
> - Put hand in front of sensor and keep the sensor and hand stationary.
> - Perform calibration routine.
> - Run iio_event_monitor.
> - Verify that a proximity event is triggered when my hand comes
> anywhere between the sensor and where I performed the calibration
> routine.
>
> Signed-off-by: Brian Masney <masneyb@xxxxxxxxxxxxx>
Applied. Thanks,

Jonathan

> ---
> drivers/staging/iio/light/tsl2x7x.c | 107 +++++-------------------------------
> 1 file changed, 15 insertions(+), 92 deletions(-)
>
> diff --git a/drivers/staging/iio/light/tsl2x7x.c b/drivers/staging/iio/light/tsl2x7x.c
> index 9c929e273135..99230d9313e1 100644
> --- a/drivers/staging/iio/light/tsl2x7x.c
> +++ b/drivers/staging/iio/light/tsl2x7x.c
> @@ -149,13 +149,6 @@ struct tsl2x7x_als_info {
> u16 lux;
> };
>
> -struct tsl2x7x_prox_stat {
> - int min;
> - int max;
> - int mean;
> - unsigned long stddev;
> -};
> -
> struct tsl2x7x_chip_info {
> int chan_table_elements;
> struct iio_chan_spec channel[4];
> @@ -771,106 +764,36 @@ static int tsl2x7x_invoke_change(struct iio_dev *indio_dev)
> return ret;
> }
>
> -static void tsl2x7x_prox_calculate(int *data, int length,
> - struct tsl2x7x_prox_stat *stat)
> -{
> - int i;
> - int sample_sum;
> - int tmp;
> -
> - if (!length)
> - length = 1;
> -
> - sample_sum = 0;
> - stat->min = INT_MAX;
> - stat->max = INT_MIN;
> - for (i = 0; i < length; i++) {
> - sample_sum += data[i];
> - stat->min = min(stat->min, data[i]);
> - stat->max = max(stat->max, data[i]);
> - }
> -
> - stat->mean = sample_sum / length;
> - sample_sum = 0;
> - for (i = 0; i < length; i++) {
> - tmp = data[i] - stat->mean;
> - sample_sum += tmp * tmp;
> - }
> - stat->stddev = int_sqrt((long)sample_sum / length);
> -}
> -
> -/**
> - * tsl2x7x_prox_cal() - Calculates std. and sets thresholds.
> - * @indio_dev: pointer to IIO device
> - *
> - * Calculates a standard deviation based on the samples,
> - * and sets the threshold accordingly.
> - */
> static int tsl2x7x_prox_cal(struct iio_dev *indio_dev)
> {
> - int prox_history[MAX_SAMPLES_CAL + 1];
> - int i, ret;
> - struct tsl2x7x_prox_stat prox_stat_data[2];
> - struct tsl2x7x_prox_stat *cal;
> struct tsl2X7X_chip *chip = iio_priv(indio_dev);
> - u8 tmp_irq_settings;
> - u8 current_state = chip->tsl2x7x_chip_status;
> -
> - if (chip->settings.prox_max_samples_cal > MAX_SAMPLES_CAL) {
> - dev_err(&chip->client->dev,
> - "max prox samples cal is too big: %d\n",
> - chip->settings.prox_max_samples_cal);
> - chip->settings.prox_max_samples_cal = MAX_SAMPLES_CAL;
> - }
> -
> - /* have to stop to change settings */
> - ret = tsl2x7x_chip_off(indio_dev);
> - if (ret < 0)
> - return ret;
> -
> - /* Enable proximity detection save just in case prox not wanted yet*/
> - tmp_irq_settings = chip->settings.interrupts_en;
> - chip->settings.interrupts_en |= TSL2X7X_CNTL_PROX_INT_ENBL;
> + int prox_history[MAX_SAMPLES_CAL + 1];
> + int i, ret, mean, max, sample_sum;
>
> - /*turn on device if not already on*/
> - ret = tsl2x7x_chip_on(indio_dev);
> - if (ret < 0)
> - return ret;
> + if (chip->settings.prox_max_samples_cal < 1 ||
> + chip->settings.prox_max_samples_cal > MAX_SAMPLES_CAL)
> + return -EINVAL;
>
> - /*gather the samples*/
> for (i = 0; i < chip->settings.prox_max_samples_cal; i++) {
> usleep_range(15000, 17500);
> ret = tsl2x7x_get_prox(indio_dev);
> if (ret < 0)
> return ret;
> +
> prox_history[i] = chip->prox_data;
> - dev_info(&chip->client->dev, "2 i=%d prox data= %d\n",
> - i, chip->prox_data);
> }
>
> - ret = tsl2x7x_chip_off(indio_dev);
> - if (ret < 0)
> - return ret;
> - cal = &prox_stat_data[PROX_STAT_CAL];
> - tsl2x7x_prox_calculate(prox_history,
> - chip->settings.prox_max_samples_cal, cal);
> - chip->settings.prox_thres_high = (cal->max << 1) - cal->mean;
> -
> - dev_info(&chip->client->dev, " cal min=%d mean=%d max=%d\n",
> - cal->min, cal->mean, cal->max);
> - dev_info(&chip->client->dev,
> - "%s proximity threshold set to %d\n",
> - chip->client->name, chip->settings.prox_thres_high);
> -
> - /* back to the way they were */
> - chip->settings.interrupts_en = tmp_irq_settings;
> - if (current_state == TSL2X7X_CHIP_WORKING) {
> - ret = tsl2x7x_chip_on(indio_dev);
> - if (ret < 0)
> - return ret;
> + sample_sum = 0;
> + max = INT_MIN;
> + for (i = 0; i < chip->settings.prox_max_samples_cal; i++) {
> + sample_sum += prox_history[i];
> + max = max(max, prox_history[i]);
> }
> + mean = sample_sum / chip->settings.prox_max_samples_cal;
>
> - return 0;
> + chip->settings.prox_thres_high = (max << 1) - mean;
> +
> + return tsl2x7x_invoke_change(indio_dev);
> }
>
> static ssize_t