hwmon: (ltc4245) Read only one GPIO pin

Read only one of the GPIO pins as an analog voltage. The ADC can be
switched to a different GPIO pin at runtime, but this is not supported.

Previously, this driver would report the analog voltage of the currently
selected GPIO pin as all three GPIO voltages: in9_input, in10_input and
in11_input.

Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: stable@kernel.org

Documentation/hwmon/ltc4245

@@ -72,9 +72,7 @@ in6_min_alarm		5v  output undervoltage alarm
 in7_min_alarm		3v  output undervoltage alarm
 in8_min_alarm		Vee (-12v) output undervoltage alarm
 
-in9_input		GPIO #1 voltage data
-in10_input		GPIO #2 voltage data
-in11_input		GPIO #3 voltage data
+in9_input		GPIO voltage data
 
 power1_input		12v power usage (mW)
 power2_input		5v  power usage (mW)

drivers/hwmon/ltc4245.c

@@ -45,9 +45,7 @@ enum ltc4245_cmd {
 	LTC4245_VEEIN			= 0x19,
 	LTC4245_VEESENSE		= 0x1a,
 	LTC4245_VEEOUT			= 0x1b,
-	LTC4245_GPIOADC1		= 0x1c,
-	LTC4245_GPIOADC2		= 0x1d,
-	LTC4245_GPIOADC3		= 0x1e,
+	LTC4245_GPIOADC			= 0x1c,
 };
 
 struct ltc4245_data {
@@ -61,7 +59,7 @@ struct ltc4245_data {
 	u8 cregs[0x08];
 
 	/* Voltage registers */
-	u8 vregs[0x0f];
+	u8 vregs[0x0d];
 };
 
 static struct ltc4245_data *ltc4245_update_device(struct device *dev)
@@ -86,7 +84,7 @@ static struct ltc4245_data *ltc4245_update_device(struct device *dev)
 				data->cregs[i] = val;
 		}
 
-		/* Read voltage registers -- 0x10 to 0x1f */
+		/* Read voltage registers -- 0x10 to 0x1c */
 		for (i = 0; i < ARRAY_SIZE(data->vregs); i++) {
 			val = i2c_smbus_read_byte_data(client, i+0x10);
 			if (unlikely(val < 0))
@@ -128,9 +126,7 @@ static int ltc4245_get_voltage(struct device *dev, u8 reg)
 	case LTC4245_VEEOUT:
 		voltage = regval * -55;
 		break;
-	case LTC4245_GPIOADC1:
-	case LTC4245_GPIOADC2:
-	case LTC4245_GPIOADC3:
+	case LTC4245_GPIOADC:
 		voltage = regval * 10;
 		break;
 	default:
@@ -297,9 +293,7 @@ LTC4245_ALARM(in7_min_alarm,	(1 << 2),	LTC4245_FAULT2);
 LTC4245_ALARM(in8_min_alarm,	(1 << 3),	LTC4245_FAULT2);
 
 /* GPIO voltages */
-LTC4245_VOLTAGE(in9_input,			LTC4245_GPIOADC1);
-LTC4245_VOLTAGE(in10_input,			LTC4245_GPIOADC2);
-LTC4245_VOLTAGE(in11_input,			LTC4245_GPIOADC3);
+LTC4245_VOLTAGE(in9_input,			LTC4245_GPIOADC);
 
 /* Power Consumption (virtual) */
 LTC4245_POWER(power1_input,			LTC4245_12VSENSE);
@@ -342,8 +336,6 @@ static struct attribute *ltc4245_attributes[] = {
 	&sensor_dev_attr_in8_min_alarm.dev_attr.attr,
 
 	&sensor_dev_attr_in9_input.dev_attr.attr,
-	&sensor_dev_attr_in10_input.dev_attr.attr,
-	&sensor_dev_attr_in11_input.dev_attr.attr,
 
 	&sensor_dev_attr_power1_input.dev_attr.attr,
 	&sensor_dev_attr_power2_input.dev_attr.attr,