iio: at91_adc: add sleep mode support

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>

1 files changed, 10 insertions, 9 deletions

diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
index 3fb3fe48a98c..7295bc5280bd 100644
--- a/drivers/iio/adc/at91_adc.c
+++ b/drivers/iio/adc/at91_adc.c
@@ -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);