Commit 04227f95 authored by Claudiu Beznea's avatar Claudiu Beznea Committed by Jonathan Cameron
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iio: adc: at91-sama5d2_adc: update trackx on emr 



Add support for updating trackx bits of EMR register. Having different
values of EMR.TRACKX when measuring temperature give a better accuracy.

Signed-off-by: default avatarClaudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220803102855.2191070-14-claudiu.beznea@microchip.com


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 426b6475

drivers/iio/adc/at91-sama5d2_adc.c

+10 −4
Original line number Diff line number Diff line
@@ -145,6 +145,10 @@ struct at91_adc_reg_layout { 
#define AT91_SAMA5D2_EMR_OSR_64SAMPLES		3

#define AT91_SAMA5D2_EMR_OSR_256SAMPLES		4



/* Extended Mode Register - TRACKX */

#define AT91_SAMA5D2_TRACKX_MASK		GENMASK(23, 22)

#define AT91_SAMA5D2_TRACKX(x)			(((x) << 22) & \

						 AT91_SAMA5D2_TRACKX_MASK)

/* Extended Mode Register - Averaging on single trigger event */

#define AT91_SAMA5D2_EMR_ASTE(V)		((V) << 20)
@@ -746,7 +750,7 @@ static void at91_adc_eoc_ena(struct at91_adc_state *st, unsigned int channel) 
}



static int at91_adc_config_emr(struct at91_adc_state *st,

			       u32 oversampling_ratio)

			       u32 oversampling_ratio, u32 trackx)

{

	/* configure the extended mode register */

	unsigned int emr = at91_adc_readl(st, EMR);
@@ -765,7 +769,7 @@ static int at91_adc_config_emr(struct at91_adc_state *st, 
	emr |= AT91_SAMA5D2_EMR_ASTE(1);



	/* delete leftover content if it's the case */

	emr &= ~osr_mask;

	emr &= ~(osr_mask | AT91_SAMA5D2_TRACKX_MASK);



	/* select oversampling ratio from configuration */

	switch (oversampling_ratio) {
@@ -791,6 +795,8 @@ static int at91_adc_config_emr(struct at91_adc_state *st, 
		break;

	}



	/* Update trackx. */

	emr |= AT91_SAMA5D2_TRACKX(trackx);

	at91_adc_writel(st, EMR, emr);



	st->oversampling_ratio = oversampling_ratio;
@@ -1706,7 +1712,7 @@ static int at91_adc_write_raw(struct iio_dev *indio_dev, 
			return ret;

		mutex_lock(&st->lock);

		/* update ratio */

		ret = at91_adc_config_emr(st, val);

		ret = at91_adc_config_emr(st, val, 0);

		mutex_unlock(&st->lock);

		iio_device_release_direct_mode(indio_dev);

		return ret;
@@ -1904,7 +1910,7 @@ static void at91_adc_hw_init(struct iio_dev *indio_dev) 
	at91_adc_setup_samp_freq(indio_dev, st->soc_info.min_sample_rate);



	/* configure extended mode register */

	at91_adc_config_emr(st, st->oversampling_ratio);

	at91_adc_config_emr(st, st->oversampling_ratio, 0);

}



static ssize_t at91_adc_get_fifo_state(struct device *dev,