adc: rockchip-saradc: add support for getting reference voltage value
Mirroring commit 97ab802aa36f ("adc: meson-saradc: add support for
getting reference voltage value") for meson-saradc, this adds support
for getting the "vref-supply" regulator and register it as the ADC's
reference voltage regulator, so clients can translate sampled ADC values
to voltage.
Signed-off-by: Peter Cai <peter@typeblog.net>
Reviewed-by: John Keeping <john@metanate.com>
Tested-by: John Keeping <john@metanate.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Philipp Tomsich <philipp.tomsich@vrull.eu>
Cc: Kever Yang <kever.yang@rock-chips.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/drivers/adc/rockchip-saradc.c b/drivers/adc/rockchip-saradc.c
index e0cbab6..760f8fe 100644
--- a/drivers/adc/rockchip-saradc.c
+++ b/drivers/adc/rockchip-saradc.c
@@ -13,6 +13,7 @@
#include <asm/io.h>
#include <linux/bitops.h>
#include <linux/err.h>
+#include <power/regulator.h>
#define SARADC_CTRL_CHN_MASK GENMASK(2, 0)
#define SARADC_CTRL_POWER_CTRL BIT(3)
@@ -100,8 +101,11 @@
int rockchip_saradc_probe(struct udevice *dev)
{
+ struct adc_uclass_plat *uc_pdata = dev_get_uclass_plat(dev);
struct rockchip_saradc_priv *priv = dev_get_priv(dev);
+ struct udevice *vref;
struct clk clk;
+ int vref_uv;
int ret;
ret = clk_get_by_index(dev, 0, &clk);
@@ -114,6 +118,23 @@
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;
}