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[98.183.112.25]) by smtp.gmail.com with ESMTPSA id 5614622812f47-3f855f69b1asm764315b6e.30.2025.03.10.13.43.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 10 Mar 2025 13:43:18 -0700 (PDT) From: David Lechner Date: Mon, 10 Mar 2025 15:43:08 -0500 Subject: [PATCH 5/5] iio: adc: ad4030: explain rearranging raw sample data Precedence: bulk X-Mailing-List: linux-iio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250310-iio-adc-ad4030-check-scan-type-err-v1-5-589e4ebd9711@baylibre.com> References: <20250310-iio-adc-ad4030-check-scan-type-err-v1-0-589e4ebd9711@baylibre.com> In-Reply-To: <20250310-iio-adc-ad4030-check-scan-type-err-v1-0-589e4ebd9711@baylibre.com> To: Lars-Peter Clausen , Michael Hennerich , =?utf-8?q?Nuno_S=C3=A1?= , Esteban Blanc , Jonathan Cameron Cc: linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, David Lechner X-Mailer: b4 0.14.2 Add a comment explaining why the raw sample data is rearranged in the in the ad4030_conversion() function. It is not so obvious from the code why this is done. Signed-off-by: David Lechner Reviewed-by: Nuno Sá --- drivers/iio/adc/ad4030.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/iio/adc/ad4030.c b/drivers/iio/adc/ad4030.c index 54ad74b96c9f256a67848330f875379edc828b0b..636f9f33e66af73d102722b984dc1230e1417d1e 100644 --- a/drivers/iio/adc/ad4030.c +++ b/drivers/iio/adc/ad4030.c @@ -646,6 +646,12 @@ static int ad4030_conversion(struct iio_dev *indio_dev) &st->rx_data.dual.diff[0], &st->rx_data.dual.diff[1]); + /* + * If no common mode voltage channel is enabled, we can use the raw + * data as is. Otherwise, we need to rearrange the data a bit to match + * the natural alignment of the IIO buffer. + */ + if (st->mode != AD4030_OUT_DATA_MD_16_DIFF_8_COM && st->mode != AD4030_OUT_DATA_MD_24_DIFF_8_COM) return 0;