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iio: at91_adc: add sleep mode support

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The sleep mode will allow to put the adc in sleep between conversion.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
Jean-Christophe PLAGNIOL-VILLARD 2013-03-29 14:54:00 +00:00 committed by Jonathan Cameron
parent 47be16b668
commit e748783c55
2 changed files with 11 additions and 9 deletions
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1
Documentation/devicetree/bindings/arm/atmel-adc.txt
View File

@ -25,6 +25,7 @@ Optional properties:
- atmel,adc-use-res: String corresponding to an identifier from
atmel,adc-res-names property. If not specified, the highest
resolution will be used.
- atmel,adc-sleep-mode: Boolean to enable sleep mode when no conversion
Optional trigger Nodes:
- Required properties:

19
drivers/iio/adc/at91_adc.c
View File

@ -52,6 +52,7 @@ struct at91_adc_state {
void __iomem *reg_base;
struct at91_adc_reg_desc *registers;
u8 startup_time;
bool sleep_mode;
struct iio_trigger **trig;
struct at91_adc_trigger *trigger_list;
u32 trigger_number;
@ -455,6 +456,8 @@ static int at91_adc_probe_dt(struct at91_adc_state *st,
}
st->num_channels = prop;
st->sleep_mode = of_property_read_bool(node, "atmel,adc-sleep-mode");
if (of_property_read_u32(node, "atmel,adc-startup-time", &prop)) {
dev_err(&idev->dev, "Missing adc-startup-time property in the DT.\n");
ret = -EINVAL;
@ -580,6 +583,7 @@ static int at91_adc_probe(struct platform_device *pdev)
struct iio_dev *idev;
struct at91_adc_state *st;
struct resource *res;
u32 reg;
idev = iio_device_alloc(sizeof(struct at91_adc_state));
if (idev == NULL) {
@ -687,16 +691,13 @@ static int at91_adc_probe(struct platform_device *pdev)
*/
ticks = round_up((st->startup_time * adc_clk /
1000000) - 1, 8) / 8;
reg = AT91_ADC_PRESCAL_(prsc) & AT91_ADC_PRESCAL;
reg |= AT91_ADC_STARTUP_(ticks) & AT91_ADC_STARTUP;
if (st->low_res)
at91_adc_writel(st, AT91_ADC_MR,
AT91_ADC_LOWRES |
(AT91_ADC_PRESCAL_(prsc) & AT91_ADC_PRESCAL) |
(AT91_ADC_STARTUP_(ticks) & AT91_ADC_STARTUP));
else
at91_adc_writel(st, AT91_ADC_MR,
(AT91_ADC_PRESCAL_(prsc) & AT91_ADC_PRESCAL) |
(AT91_ADC_STARTUP_(ticks) & AT91_ADC_STARTUP));
reg |= AT91_ADC_LOWRES;
if (st->sleep_mode)
reg |= AT91_ADC_SLEEP;
at91_adc_writel(st, AT91_ADC_MR, reg);
/* Setup the ADC channels available on the board */
ret = at91_adc_channel_init(idev);