From 63f004e7aae17a6b6048c88ce7e39d64e58c08c1 Mon Sep 17 00:00:00 2001
From: Fabrice Gasnier
Date: Mon, 12 Nov 2018 14:03:58 +0100
Subject: dm: adc: add uclass's mask and conversion helpers

Add two functions to ADC uclass's:
- adc_raw_to_uV() to ease ADC raw value conversion to microvolts
- adc_channel_mask() to get channels on consumer side

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
---
 drivers/adc/adc-uclass.c | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

(limited to 'drivers')

diff --git a/drivers/adc/adc-uclass.c b/drivers/adc/adc-uclass.c
index 738c1eabdc3..0a492eba543 100644
--- a/drivers/adc/adc-uclass.c
+++ b/drivers/adc/adc-uclass.c
@@ -6,6 +6,7 @@
 
 #include <common.h>
 #include <errno.h>
+#include <div64.h>
 #include <dm.h>
 #include <dm/lists.h>
 #include <dm/device-internal.h>
@@ -77,6 +78,18 @@ int adc_data_mask(struct udevice *dev, unsigned int *data_mask)
 	return 0;
 }
 
+int adc_channel_mask(struct udevice *dev, unsigned int *channel_mask)
+{
+	struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev);
+
+	if (!uc_pdata)
+		return -ENOSYS;
+
+	*channel_mask = uc_pdata->channel_mask;
+
+	return 0;
+}
+
 int adc_stop(struct udevice *dev)
 {
 	const struct adc_ops *ops = dev_get_driver_ops(dev);
@@ -329,6 +342,30 @@ int adc_vss_value(struct udevice *dev, int *uV)
 	return 0;
 }
 
+int adc_raw_to_uV(struct udevice *dev, unsigned int raw, int *uV)
+{
+	unsigned int data_mask;
+	int ret, val, vref;
+	u64 raw64 = raw;
+
+	ret = adc_vdd_value(dev, &vref);
+	if (ret)
+		return ret;
+
+	if (!adc_vss_value(dev, &val))
+		vref -= val;
+
+	ret = adc_data_mask(dev, &data_mask);
+	if (ret)
+		return ret;
+
+	raw64 *= vref;
+	do_div(raw64, data_mask);
+	*uV = raw64;
+
+	return 0;
+}
+
 static int adc_vdd_platdata_set(struct udevice *dev)
 {
 	struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev);
-- 
cgit v1.2.3