From: Miquel Raynal Date: Fri, 11 Oct 2019 14:43:40 +0000 (+0200) Subject: iio: adc: max1027: Add debugfs register read support X-Git-Tag: v5.15~5053^2~130^2~62 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=038696f8bd2f2ed188827fbcfec3a38f8a2aea4f;p=platform%2Fkernel%2Flinux-starfive.git iio: adc: max1027: Add debugfs register read support Until now, only write operations were supported. Force two bytes read operation when reading, which should fit most of the development purposes. Of course, extended operations like buffered reads on multiple channels or even temperature + voltage reads will not be read entirely. Usually, just starting a new operation will work but in any case a software reset (done through the debufs interface too) will return the device in a usable state. Signed-off-by: Miquel Raynal Signed-off-by: Jonathan Cameron --- diff --git a/drivers/iio/adc/max1027.c b/drivers/iio/adc/max1027.c index 2148834..6cdfe9e 100644 --- a/drivers/iio/adc/max1027.c +++ b/drivers/iio/adc/max1027.c @@ -309,8 +309,11 @@ static int max1027_debugfs_reg_access(struct iio_dev *indio_dev, struct max1027_state *st = iio_priv(indio_dev); u8 *val = (u8 *)st->buffer; - if (readval != NULL) - return -EINVAL; + if (readval) { + int ret = spi_read(st->spi, val, 2); + *readval = be16_to_cpu(st->buffer[0]); + return ret; + } *val = (u8)writeval; return spi_write(st->spi, val, 1);