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Commit 94b24230 authored by Ludovic Desroches's avatar Ludovic Desroches Committed by Jonathan Cameron
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iio:adc:at91-sama5d2: cleanup mode register use 



Do not erase previous configuration of the mode register when setting
the sampling frequency.

Signed-off-by: default avatarLudovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent 22d199a5

drivers/iio/adc/at91-sama5d2_adc.c

+10 −5
Original line number Diff line number Diff line
@@ -66,8 +66,10 @@ 
#define	AT91_SAMA5D2_MR_PRESCAL(v)	((v) << AT91_SAMA5D2_MR_PRESCAL_OFFSET)

#define	AT91_SAMA5D2_MR_PRESCAL_OFFSET	8

#define	AT91_SAMA5D2_MR_PRESCAL_MAX	0xff

#define AT91_SAMA5D2_MR_PRESCAL_MASK	GENMASK(15, 8)

/* Startup Time */

#define	AT91_SAMA5D2_MR_STARTUP(v)	((v) << 16)

#define AT91_SAMA5D2_MR_STARTUP_MASK	GENMASK(19, 16)

/* Analog Change */

#define	AT91_SAMA5D2_MR_ANACH		BIT(23)

/* Tracking Time */
@@ -226,7 +228,7 @@ static unsigned at91_adc_startup_time(unsigned startup_time_min, 
static void at91_adc_setup_samp_freq(struct at91_adc_state *st, unsigned freq)

{

	struct iio_dev *indio_dev = iio_priv_to_dev(st);

	unsigned f_per, prescal, startup;

	unsigned f_per, prescal, startup, mr;



	f_per = clk_get_rate(st->per_clk);

	prescal = (f_per / (2 * freq)) - 1;
@@ -234,10 +236,11 @@ static void at91_adc_setup_samp_freq(struct at91_adc_state *st, unsigned freq) 
	startup = at91_adc_startup_time(st->soc_info.startup_time,

					freq / 1000);



	at91_adc_writel(st, AT91_SAMA5D2_MR,

			AT91_SAMA5D2_MR_TRANSFER(2)

			| AT91_SAMA5D2_MR_STARTUP(startup)

			| AT91_SAMA5D2_MR_PRESCAL(prescal));

	mr = at91_adc_readl(st, AT91_SAMA5D2_MR);

	mr &= ~(AT91_SAMA5D2_MR_STARTUP_MASK | AT91_SAMA5D2_MR_PRESCAL_MASK);

	mr |= AT91_SAMA5D2_MR_STARTUP(startup);

	mr |= AT91_SAMA5D2_MR_PRESCAL(prescal);

	at91_adc_writel(st, AT91_SAMA5D2_MR, mr);



	dev_dbg(&indio_dev->dev, "freq: %u, startup: %u, prescal: %u\n",

		freq, startup, prescal);
@@ -444,6 +447,8 @@ static int at91_adc_probe(struct platform_device *pdev) 


	at91_adc_writel(st, AT91_SAMA5D2_CR, AT91_SAMA5D2_CR_SWRST);

	at91_adc_writel(st, AT91_SAMA5D2_IDR, 0xffffffff);

	/* Transfer field must be set to 2 according to the datasheet. */

	at91_adc_writel(st, AT91_SAMA5D2_MR, AT91_SAMA5D2_MR_TRANSFER(2));



	at91_adc_setup_samp_freq(st, st->soc_info.min_sample_rate);