diff options
Diffstat (limited to 'drivers/iio/adc/mcp3911.c')
| -rw-r--r-- | drivers/iio/adc/mcp3911.c | 28 |
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", |