[PATCH v7 3/5] adc: meson-saradc: add support for getting reference voltage value
Marek Szyprowski
m.szyprowski at samsung.com
Thu Feb 18 11:33:16 CET 2021
Add support for getting the 'vref-supply' regulator and register it as
ADC's reference voltage regulator, so clients can translate sampled ADC
values to the voltage.
Signed-off-by: Marek Szyprowski <m.szyprowski at samsung.com>
Reviewed-by: Simon Glass <sjg at chromium.org>
---
drivers/adc/meson-saradc.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/drivers/adc/meson-saradc.c b/drivers/adc/meson-saradc.c
index 21db55831d..1a45a3a265 100644
--- a/drivers/adc/meson-saradc.c
+++ b/drivers/adc/meson-saradc.c
@@ -18,6 +18,7 @@
#include <linux/delay.h>
#include <linux/math64.h>
#include <linux/bitfield.h>
+#include <power/regulator.h>
#define MESON_SAR_ADC_REG0 0x00
#define MESON_SAR_ADC_REG0_PANEL_DETECT BIT(31)
@@ -656,7 +657,10 @@ static int meson_saradc_stop(struct udevice *dev)
static int meson_saradc_probe(struct udevice *dev)
{
+ struct adc_uclass_plat *uc_pdata = dev_get_uclass_plat(dev);
struct meson_saradc_priv *priv = dev_get_priv(dev);
+ struct udevice *vref;
+ int vref_uv;
int ret;
ret = regmap_init_mem(dev_ofnode(dev), &priv->regmap);
@@ -675,6 +679,23 @@ static int meson_saradc_probe(struct udevice *dev)
priv->active_channel = -1;
+ ret = device_get_supply_regulator(dev, "vref-supply", &vref);
+ if (ret) {
+ printf("can't get vref-supply: %d\n", ret);
+ return ret;
+ }
+
+ vref_uv = regulator_get_value(vref);
+ if (vref_uv < 0) {
+ printf("can't get vref-supply value: %d\n", vref_uv);
+ return vref_uv;
+ }
+
+ /* VDD supplied by common vref pin */
+ uc_pdata->vdd_supply = vref;
+ uc_pdata->vdd_microvolts = vref_uv;
+ uc_pdata->vss_microvolts = 0;
+
return 0;
}
--
2.17.1
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