From 4ea71e5cee8ad52407ee95c3548d0887eedae301 Mon Sep 17 00:00:00 2001 From: Akinobu Mita Date: Fri, 8 Jan 2016 00:40:30 +0900 Subject: [PATCH] iio: adc: mcp320x: support more differential voltage measurement mcp320x driver supports the pseudo-differential mode by in_voltage'IN+'-voltage'IN-'_raw where (IN+, IN-) = (0, 1), (2, 3), ... mcp320x chips except MCP3X01 can also select swapped IN+ and IN- pairs in the pseudo-differential mode. i.e. in_voltage'IN+'-voltage'IN-'_raw where (IN+, IN-) = (1, 0), (3, 2), ... If the voltage level of IN+ is equal to or less than IN-, the resultant code will be 000h. So it is useful to provide these, too. Signed-off-by: Akinobu Mita Cc: Oskar Andero Cc: Jonathan Cameron Cc: Hartmut Knaack Cc: Lars-Peter Clausen Cc: Peter Meerwald Cc: linux-iio@vger.kernel.org Signed-off-by: Jonathan Cameron --- drivers/iio/adc/mcp320x.c | 31 +++++++++++++++++++------------ 1 file changed, 19 insertions(+), 12 deletions(-) diff --git a/drivers/iio/adc/mcp320x.c b/drivers/iio/adc/mcp320x.c index d1c05f6eed18..a850ca7d1eda 100644 --- a/drivers/iio/adc/mcp320x.c +++ b/drivers/iio/adc/mcp320x.c @@ -187,26 +187,27 @@ out: .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \ } -#define MCP320X_VOLTAGE_CHANNEL_DIFF(num) \ +#define MCP320X_VOLTAGE_CHANNEL_DIFF(chan1, chan2) \ { \ .type = IIO_VOLTAGE, \ .indexed = 1, \ - .channel = (num * 2), \ - .channel2 = (num * 2 + 1), \ - .address = (num * 2), \ + .channel = (chan1), \ + .channel2 = (chan2), \ + .address = (chan1), \ .differential = 1, \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \ } static const struct iio_chan_spec mcp3201_channels[] = { - MCP320X_VOLTAGE_CHANNEL_DIFF(0), + MCP320X_VOLTAGE_CHANNEL_DIFF(0, 1), }; static const struct iio_chan_spec mcp3202_channels[] = { MCP320X_VOLTAGE_CHANNEL(0), MCP320X_VOLTAGE_CHANNEL(1), - MCP320X_VOLTAGE_CHANNEL_DIFF(0), + MCP320X_VOLTAGE_CHANNEL_DIFF(0, 1), + MCP320X_VOLTAGE_CHANNEL_DIFF(1, 0), }; static const struct iio_chan_spec mcp3204_channels[] = { @@ -214,8 +215,10 @@ static const struct iio_chan_spec mcp3204_channels[] = { MCP320X_VOLTAGE_CHANNEL(1), MCP320X_VOLTAGE_CHANNEL(2), MCP320X_VOLTAGE_CHANNEL(3), - MCP320X_VOLTAGE_CHANNEL_DIFF(0), - MCP320X_VOLTAGE_CHANNEL_DIFF(1), + MCP320X_VOLTAGE_CHANNEL_DIFF(0, 1), + MCP320X_VOLTAGE_CHANNEL_DIFF(1, 0), + MCP320X_VOLTAGE_CHANNEL_DIFF(2, 3), + MCP320X_VOLTAGE_CHANNEL_DIFF(3, 2), }; static const struct iio_chan_spec mcp3208_channels[] = { @@ -227,10 +230,14 @@ static const struct iio_chan_spec mcp3208_channels[] = { MCP320X_VOLTAGE_CHANNEL(5), MCP320X_VOLTAGE_CHANNEL(6), MCP320X_VOLTAGE_CHANNEL(7), - MCP320X_VOLTAGE_CHANNEL_DIFF(0), - MCP320X_VOLTAGE_CHANNEL_DIFF(1), - MCP320X_VOLTAGE_CHANNEL_DIFF(2), - MCP320X_VOLTAGE_CHANNEL_DIFF(3), + MCP320X_VOLTAGE_CHANNEL_DIFF(0, 1), + MCP320X_VOLTAGE_CHANNEL_DIFF(1, 0), + MCP320X_VOLTAGE_CHANNEL_DIFF(2, 3), + MCP320X_VOLTAGE_CHANNEL_DIFF(3, 2), + MCP320X_VOLTAGE_CHANNEL_DIFF(4, 5), + MCP320X_VOLTAGE_CHANNEL_DIFF(5, 4), + MCP320X_VOLTAGE_CHANNEL_DIFF(6, 7), + MCP320X_VOLTAGE_CHANNEL_DIFF(7, 6), }; static const struct iio_info mcp320x_info = { -- 2.30.2