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path: root/drivers/iio/adc/mcp3911.c
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Diffstat (limited to 'drivers/iio/adc/mcp3911.c')
-rw-r--r--drivers/iio/adc/mcp3911.c28
1 files changed, 22 insertions, 6 deletions
diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c
index 1cb4590fe412..890af7dca62d 100644
--- a/drivers/iio/adc/mcp3911.c
+++ b/drivers/iio/adc/mcp3911.c
@@ -40,8 +40,8 @@
#define MCP3911_CHANNEL(x) (MCP3911_REG_CHANNEL0 + x * 3)
#define MCP3911_OFFCAL(x) (MCP3911_REG_OFFCAL_CH0 + x * 6)
-/* Internal voltage reference in uV */
-#define MCP3911_INT_VREF_UV 1200000
+/* Internal voltage reference in mV */
+#define MCP3911_INT_VREF_MV 1200
#define MCP3911_REG_READ(reg, id) ((((reg) << 1) | ((id) << 5) | (1 << 0)) & 0xff)
#define MCP3911_REG_WRITE(reg, id) ((((reg) << 1) | ((id) << 5) | (0 << 0)) & 0xff)
@@ -113,6 +113,8 @@ static int mcp3911_read_raw(struct iio_dev *indio_dev,
if (ret)
goto out;
+ *val = sign_extend32(*val, 23);
+
ret = IIO_VAL_INT;
break;
@@ -137,11 +139,18 @@ static int mcp3911_read_raw(struct iio_dev *indio_dev,
*val = ret / 1000;
} else {
- *val = MCP3911_INT_VREF_UV;
+ *val = MCP3911_INT_VREF_MV;
}
- *val2 = 24;
- ret = IIO_VAL_FRACTIONAL_LOG2;
+ /*
+ * For 24bit Conversion
+ * Raw = ((Voltage)/(Vref) * 2^23 * Gain * 1.5
+ * Voltage = Raw * (Vref)/(2^23 * Gain * 1.5)
+ */
+
+ /* val2 = (2^23 * 1.5) */
+ *val2 = 12582912;
+ ret = IIO_VAL_FRACTIONAL;
break;
}
@@ -208,7 +217,14 @@ static int mcp3911_config(struct mcp3911 *adc)
u32 configreg;
int ret;
- device_property_read_u32(dev, "device-addr", &adc->dev_addr);
+ ret = device_property_read_u32(dev, "microchip,device-addr", &adc->dev_addr);
+
+ /*
+ * Fallback to "device-addr" due to historical mismatch between
+ * dt-bindings and implementation
+ */
+ if (ret)
+ device_property_read_u32(dev, "device-addr", &adc->dev_addr);
if (adc->dev_addr > 3) {
dev_err(&adc->spi->dev,
"invalid device address (%i). Must be in range 0-3.\n",