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From:   Oleksij Rempel <o.rempel@pengutronix.de>
To:     Jean Delvare <jdelvare@suse.com>, Markus Pietrek <mpie@msc-ge.com>,
        Guenter Roeck <linux@roeck-us.net>
Cc:     Oleksij Rempel <o.rempel@pengutronix.de>, kernel@pengutronix.de,
        linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH V1 2/2] hwmon: (powr1220) add scaled voltage support
Date:   Mon, 27 Jan 2020 11:25:40 +0100
Message-Id: <20200127102540.31742-2-o.rempel@pengutronix.de>
In-Reply-To: <20200127102540.31742-1-o.rempel@pengutronix.de>
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From: Markus Pietrek <mpie@msc-ge.com>

On some (or may be all?) boards, voltage measured by powr1220 do not
reflect real system configuration. This patch provides scale option to
set board specific configuration.

Signed-off-by: Markus Pietrek <mpie@msc-ge.com>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
 drivers/hwmon/powr1220.c | 155 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 155 insertions(+)

diff --git a/drivers/hwmon/powr1220.c b/drivers/hwmon/powr1220.c
index ad7a82f132e6..7cb2a6d3b3d8 100644
--- a/drivers/hwmon/powr1220.c
+++ b/drivers/hwmon/powr1220.c
@@ -74,6 +74,14 @@ enum powr1220_adc_values {
 	MAX_POWR1220_ADC_VALUES
 };
 
+/* Real value = (measured-value * factor) / divisor.
+ * A divisor of 0 disables scaling and is identical to factor==1 && divisor==1.
+ */
+struct adc_scale {
+	int factor;
+	int divisor;
+};
+
 struct powr1220_data {
 	struct i2c_client *client;
 	struct mutex update_lock;
@@ -84,6 +92,7 @@ struct powr1220_data {
 	/* values */
 	int adc_maxes[MAX_POWR1220_ADC_VALUES];
 	int adc_values[MAX_POWR1220_ADC_VALUES];
+	struct adc_scale adc_scales[MAX_POWR1220_ADC_VALUES];
 };
 
 static const char * const input_names[] = {
@@ -184,6 +193,29 @@ static ssize_t powr1220_voltage_show(struct device *dev,
 	return sprintf(buf, "%d\n", adc_val);
 }
 
+static ssize_t powr1220_scaled_voltage_show(struct device *dev,
+	struct device_attribute *dev_attr, char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
+	struct powr1220_data *data = dev_get_drvdata(dev);
+	int adc_val = powr1220_read_adc(dev, attr->index);
+	struct adc_scale *scale;
+
+	if (adc_val < 0)
+		return adc_val;
+
+	scale = &data->adc_scales[attr->index];
+	if (scale->divisor) {
+		int64_t lscaled = adc_val;
+
+		lscaled *= scale->factor;
+		lscaled /= scale->divisor;
+		adc_val = (int) lscaled;
+	}
+
+	return sprintf(buf, "%d\n", adc_val);
+}
+
 /* Shows the maximum setting associated with the specified ADC channel */
 static ssize_t powr1220_max_show(struct device *dev,
 				 struct device_attribute *dev_attr, char *buf)
@@ -204,6 +236,38 @@ static ssize_t powr1220_label_show(struct device *dev,
 	return sprintf(buf, "%s\n", input_names[attr->index]);
 }
 
+/* Shows the scale for the read value.
+ * real value = (measured value * factor) / divisor. n/0 means scaling disabled
+ * and raw values are printed.
+ */
+static ssize_t powr1220_scale_show(struct device *dev,
+	struct device_attribute *dev_attr, char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
+	struct powr1220_data *data = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d/%d\n", data->adc_scales[attr->index].factor,
+		       data->adc_scales[attr->index].divisor);
+}
+
+static ssize_t powr1220_scale_store(struct device *dev,
+				    struct device_attribute *dev_attr,
+				    const char *buf, size_t count)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
+	struct powr1220_data *data = dev_get_drvdata(dev);
+	int factor;
+	int divisor;
+
+	if (sscanf(buf, "%d/%d", &factor, &divisor) != 2)
+		return -EINVAL;
+
+	data->adc_scales[attr->index].factor = factor;
+	data->adc_scales[attr->index].divisor = divisor;
+
+	return count;
+}
+
 static SENSOR_DEVICE_ATTR_RO(in0_input, powr1220_voltage, VMON1);
 static SENSOR_DEVICE_ATTR_RO(in1_input, powr1220_voltage, VMON2);
 static SENSOR_DEVICE_ATTR_RO(in2_input, powr1220_voltage, VMON3);
@@ -219,6 +283,26 @@ static SENSOR_DEVICE_ATTR_RO(in11_input, powr1220_voltage, VMON12);
 static SENSOR_DEVICE_ATTR_RO(in12_input, powr1220_voltage, VCCA);
 static SENSOR_DEVICE_ATTR_RO(in13_input, powr1220_voltage, VCCINP);
 
+static SENSOR_DEVICE_ATTR_RO(in0_scaled_input, powr1220_scaled_voltage, VMON1);
+static SENSOR_DEVICE_ATTR_RO(in1_scaled_input, powr1220_scaled_voltage, VMON2);
+static SENSOR_DEVICE_ATTR_RO(in2_scaled_input, powr1220_scaled_voltage, VMON3);
+static SENSOR_DEVICE_ATTR_RO(in3_scaled_input, powr1220_scaled_voltage, VMON4);
+static SENSOR_DEVICE_ATTR_RO(in4_scaled_input, powr1220_scaled_voltage, VMON5);
+static SENSOR_DEVICE_ATTR_RO(in5_scaled_input, powr1220_scaled_voltage, VMON6);
+static SENSOR_DEVICE_ATTR_RO(in6_scaled_input, powr1220_scaled_voltage, VMON7);
+static SENSOR_DEVICE_ATTR_RO(in7_scaled_input, powr1220_scaled_voltage, VMON8);
+static SENSOR_DEVICE_ATTR_RO(in8_scaled_input, powr1220_scaled_voltage, VMON9);
+static SENSOR_DEVICE_ATTR_RO(in9_scaled_input, powr1220_scaled_voltage,
+			     VMON10);
+static SENSOR_DEVICE_ATTR_RO(in10_scaled_input, powr1220_scaled_voltage,
+			     VMON11);
+static SENSOR_DEVICE_ATTR_RO(in11_scaled_input, powr1220_scaled_voltage,
+			     VMON12);
+static SENSOR_DEVICE_ATTR_RO(in12_scaled_input, powr1220_scaled_voltage,
+			     VCCA);
+static SENSOR_DEVICE_ATTR_RO(in13_scaled_input, powr1220_scaled_voltage,
+			     VCCINP);
+
 static SENSOR_DEVICE_ATTR_RO(in0_highest, powr1220_max, VMON1);
 static SENSOR_DEVICE_ATTR_RO(in1_highest, powr1220_max, VMON2);
 static SENSOR_DEVICE_ATTR_RO(in2_highest, powr1220_max, VMON3);
@@ -249,6 +333,21 @@ static SENSOR_DEVICE_ATTR_RO(in11_label, powr1220_label, VMON12);
 static SENSOR_DEVICE_ATTR_RO(in12_label, powr1220_label, VCCA);
 static SENSOR_DEVICE_ATTR_RO(in13_label, powr1220_label, VCCINP);
 
+static SENSOR_DEVICE_ATTR_RW(in0_scale, powr1220_scale, VMON1);
+static SENSOR_DEVICE_ATTR_RW(in1_scale, powr1220_scale, VMON2);
+static SENSOR_DEVICE_ATTR_RW(in2_scale, powr1220_scale, VMON3);
+static SENSOR_DEVICE_ATTR_RW(in3_scale, powr1220_scale, VMON4);
+static SENSOR_DEVICE_ATTR_RW(in4_scale, powr1220_scale, VMON5);
+static SENSOR_DEVICE_ATTR_RW(in5_scale, powr1220_scale, VMON6);
+static SENSOR_DEVICE_ATTR_RW(in6_scale, powr1220_scale, VMON7);
+static SENSOR_DEVICE_ATTR_RW(in7_scale, powr1220_scale, VMON8);
+static SENSOR_DEVICE_ATTR_RW(in8_scale, powr1220_scale, VMON9);
+static SENSOR_DEVICE_ATTR_RW(in9_scale, powr1220_scale, VMON10);
+static SENSOR_DEVICE_ATTR_RW(in10_scale, powr1220_scale, VMON11);
+static SENSOR_DEVICE_ATTR_RW(in11_scale, powr1220_scale, VMON12);
+static SENSOR_DEVICE_ATTR_RW(in12_scale, powr1220_scale, VCCA);
+static SENSOR_DEVICE_ATTR_RW(in13_scale, powr1220_scale, VCCINP);
+
 static struct attribute *powr1014_attrs[] = {
 	&sensor_dev_attr_in0_input.dev_attr.attr,
 	&sensor_dev_attr_in1_input.dev_attr.attr,
@@ -263,6 +362,19 @@ static struct attribute *powr1014_attrs[] = {
 	&sensor_dev_attr_in12_input.dev_attr.attr,
 	&sensor_dev_attr_in13_input.dev_attr.attr,
 
+	&sensor_dev_attr_in0_scaled_input.dev_attr.attr,
+	&sensor_dev_attr_in1_scaled_input.dev_attr.attr,
+	&sensor_dev_attr_in2_scaled_input.dev_attr.attr,
+	&sensor_dev_attr_in3_scaled_input.dev_attr.attr,
+	&sensor_dev_attr_in4_scaled_input.dev_attr.attr,
+	&sensor_dev_attr_in5_scaled_input.dev_attr.attr,
+	&sensor_dev_attr_in6_scaled_input.dev_attr.attr,
+	&sensor_dev_attr_in7_scaled_input.dev_attr.attr,
+	&sensor_dev_attr_in8_scaled_input.dev_attr.attr,
+	&sensor_dev_attr_in9_scaled_input.dev_attr.attr,
+	&sensor_dev_attr_in12_scaled_input.dev_attr.attr,
+	&sensor_dev_attr_in13_scaled_input.dev_attr.attr,
+
 	&sensor_dev_attr_in0_highest.dev_attr.attr,
 	&sensor_dev_attr_in1_highest.dev_attr.attr,
 	&sensor_dev_attr_in2_highest.dev_attr.attr,
@@ -289,6 +401,19 @@ static struct attribute *powr1014_attrs[] = {
 	&sensor_dev_attr_in12_label.dev_attr.attr,
 	&sensor_dev_attr_in13_label.dev_attr.attr,
 
+	&sensor_dev_attr_in0_scale.dev_attr.attr,
+	&sensor_dev_attr_in1_scale.dev_attr.attr,
+	&sensor_dev_attr_in2_scale.dev_attr.attr,
+	&sensor_dev_attr_in3_scale.dev_attr.attr,
+	&sensor_dev_attr_in4_scale.dev_attr.attr,
+	&sensor_dev_attr_in5_scale.dev_attr.attr,
+	&sensor_dev_attr_in6_scale.dev_attr.attr,
+	&sensor_dev_attr_in7_scale.dev_attr.attr,
+	&sensor_dev_attr_in8_scale.dev_attr.attr,
+	&sensor_dev_attr_in9_scale.dev_attr.attr,
+	&sensor_dev_attr_in12_scale.dev_attr.attr,
+	&sensor_dev_attr_in13_scale.dev_attr.attr,
+
 	NULL
 };
 
@@ -310,6 +435,21 @@ static struct attribute *powr1220_attrs[] = {
 	&sensor_dev_attr_in12_input.dev_attr.attr,
 	&sensor_dev_attr_in13_input.dev_attr.attr,
 
+	&sensor_dev_attr_in0_scaled_input.dev_attr.attr,
+	&sensor_dev_attr_in1_scaled_input.dev_attr.attr,
+	&sensor_dev_attr_in2_scaled_input.dev_attr.attr,
+	&sensor_dev_attr_in3_scaled_input.dev_attr.attr,
+	&sensor_dev_attr_in4_scaled_input.dev_attr.attr,
+	&sensor_dev_attr_in5_scaled_input.dev_attr.attr,
+	&sensor_dev_attr_in6_scaled_input.dev_attr.attr,
+	&sensor_dev_attr_in7_scaled_input.dev_attr.attr,
+	&sensor_dev_attr_in8_scaled_input.dev_attr.attr,
+	&sensor_dev_attr_in9_scaled_input.dev_attr.attr,
+	&sensor_dev_attr_in10_scaled_input.dev_attr.attr,
+	&sensor_dev_attr_in11_scaled_input.dev_attr.attr,
+	&sensor_dev_attr_in12_scaled_input.dev_attr.attr,
+	&sensor_dev_attr_in13_scaled_input.dev_attr.attr,
+
 	&sensor_dev_attr_in0_highest.dev_attr.attr,
 	&sensor_dev_attr_in1_highest.dev_attr.attr,
 	&sensor_dev_attr_in2_highest.dev_attr.attr,
@@ -340,6 +480,21 @@ static struct attribute *powr1220_attrs[] = {
 	&sensor_dev_attr_in12_label.dev_attr.attr,
 	&sensor_dev_attr_in13_label.dev_attr.attr,
 
+	&sensor_dev_attr_in0_scale.dev_attr.attr,
+	&sensor_dev_attr_in1_scale.dev_attr.attr,
+	&sensor_dev_attr_in2_scale.dev_attr.attr,
+	&sensor_dev_attr_in3_scale.dev_attr.attr,
+	&sensor_dev_attr_in4_scale.dev_attr.attr,
+	&sensor_dev_attr_in5_scale.dev_attr.attr,
+	&sensor_dev_attr_in6_scale.dev_attr.attr,
+	&sensor_dev_attr_in7_scale.dev_attr.attr,
+	&sensor_dev_attr_in8_scale.dev_attr.attr,
+	&sensor_dev_attr_in9_scale.dev_attr.attr,
+	&sensor_dev_attr_in10_scale.dev_attr.attr,
+	&sensor_dev_attr_in11_scale.dev_attr.attr,
+	&sensor_dev_attr_in12_scale.dev_attr.attr,
+	&sensor_dev_attr_in13_scale.dev_attr.attr,
+
 	NULL
 };
 
-- 
2.25.0