On Tue, Jul 14, 2015 at 11:04 PM, Jonathan Cameron <jic23@xxxxxxxxxx> wrote: > > > On 14 July 2015 14:36:20 BST, Andrea Galbusera <gizero@xxxxxxxxx> wrote: >>According to the datasheet, the 2 MSBs for parts 3001 and 3201 are >>unspecified and should be masked out > Theoretical issue or one with observed bad effects? Hi! Thanks for reviewing. While in the business of adding support for 3301, I couldn't figure out why no masking wasn't done for similar parts like 3001 and 3201. Further investigation of previous patches reviews [1], where masking was suggested and initially implemented, convinced me the bit was lost somewhere, with no explicit motivation. Nevertheless, 3301 is the only chip of the family I have at hands: hence, yes, this specific patch in the set is addressing a theoretical issue. [1] http://marc.info/?l=linux-iio&m=140748835509583&w=2 > Changes the path and timing of this getting applied. Patch itself is fine either way! >> >>Signed-off-by: Andrea Galbusera <gizero@xxxxxxxxx> >>--- >> >>This was already suggested but for some reason got lost during review >>of a >>previous patch. See http://marc.info/?l=linux-iio&m=140748835509583&w=2 >>and following discussion >> >> drivers/iio/adc/mcp320x.c | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >>diff --git a/drivers/iio/adc/mcp320x.c b/drivers/iio/adc/mcp320x.c >>index 8d9c9b9..0673ee7 100644 >>--- a/drivers/iio/adc/mcp320x.c >>+++ b/drivers/iio/adc/mcp320x.c >>@@ -114,13 +114,13 @@ static int mcp320x_adc_conversion(struct mcp320x >>*adc, u8 channel, >> >> switch (device_index) { >> case mcp3001: >>- return (adc->rx_buf[0] << 5 | adc->rx_buf[1] >> 3); >>+ return ((adc->rx_buf[0] & 0x1f) << 5 | adc->rx_buf[1] >> 3); >> case mcp3002: >> case mcp3004: >> case mcp3008: >> return (adc->rx_buf[0] << 2 | adc->rx_buf[1] >> 6); >> case mcp3201: >>- return (adc->rx_buf[0] << 7 | adc->rx_buf[1] >> 1); >>+ return ((adc->rx_buf[0] & 0x1f) << 7 | adc->rx_buf[1] >> 1); >> case mcp3202: >> case mcp3204: >> case mcp3208: > > -- > Sent from my Android device with K-9 Mail. Please excuse my brevity. -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
