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Wed, 14 Jun 2023 07:49:33 +0000 (UTC) From: Herve Codina To: Herve Codina , Liam Girdwood , Mark Brown , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Jonathan Cameron , Lars-Peter Clausen , Jaroslav Kysela , Takashi Iwai , Kuninori Morimoto , Andy Shevchenko Cc: alsa-devel@alsa-project.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org, Christophe Leroy , Thomas Petazzoni , Jonathan Cameron Subject: [PATCH v4 04/13] iio: consumer.h: Fix raw values documentation notes Date: Wed, 14 Jun 2023 09:48:55 +0200 Message-Id: <20230614074904.29085-5-herve.codina@bootlin.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230614074904.29085-1-herve.codina@bootlin.com> References: <20230614074904.29085-1-herve.codina@bootlin.com> MIME-Version: 1.0 Message-ID-Hash: ZKHSNPHYNWBV4VBBOKQONQWY3NAFKHQ6 X-Message-ID-Hash: ZKHSNPHYNWBV4VBBOKQONQWY3NAFKHQ6 X-MailFrom: herve.codina@bootlin.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; header-match-alsa-devel.alsa-project.org-0; header-match-alsa-devel.alsa-project.org-1; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.8 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: The raw values notes mention 'ADC counts' and are not fully accurate. Reword the notes in order to remove the 'ADC counts' and describe the conversion needed between a raw value and a value in the standard units. Signed-off-by: Herve Codina Acked-by: Jonathan Cameron Reviewed-by: Andy Shevchenko --- include/linux/iio/consumer.h | 25 +++++++++++++++---------- 1 file changed, 15 insertions(+), 10 deletions(-) diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h index 6802596b017c..f536820b9cf2 100644 --- a/include/linux/iio/consumer.h +++ b/include/linux/iio/consumer.h @@ -201,8 +201,9 @@ struct iio_dev * @chan: The channel being queried. * @val: Value read back. * - * Note raw reads from iio channels are in adc counts and hence - * scale will need to be applied if standard units required. + * Note, if standard units are required, raw reads from iio channels + * need the offset (default 0) and scale (default 1) to be applied + * as (raw + offset) * scale. */ int iio_read_channel_raw(struct iio_channel *chan, int *val); @@ -212,8 +213,9 @@ int iio_read_channel_raw(struct iio_channel *chan, * @chan: The channel being queried. * @val: Value read back. * - * Note raw reads from iio channels are in adc counts and hence - * scale will need to be applied if standard units required. + * Note, if standard units are required, raw reads from iio channels + * need the offset (default 0) and scale (default 1) to be applied + * as (raw + offset) * scale. * * In opposit to the normal iio_read_channel_raw this function * returns the average of multiple reads. @@ -281,8 +283,9 @@ int iio_read_channel_attribute(struct iio_channel *chan, int *val, * @chan: The channel being queried. * @val: Value being written. * - * Note raw writes to iio channels are in dac counts and hence - * scale will need to be applied if standard units required. + * Note that for raw writes to iio channels, if the value provided is + * in standard units, the affect of the scale and offset must be removed + * as (value / scale) - offset. */ int iio_write_channel_raw(struct iio_channel *chan, int val); @@ -292,8 +295,9 @@ int iio_write_channel_raw(struct iio_channel *chan, int val); * @chan: The channel being queried. * @val: Value read back. * - * Note raw reads from iio channels are in adc counts and hence - * scale will need to be applied if standard units are required. + * Note, if standard units are required, raw reads from iio channels + * need the offset (default 0) and scale (default 1) to be applied + * as (raw + offset) * scale. */ int iio_read_max_channel_raw(struct iio_channel *chan, int *val); @@ -308,8 +312,9 @@ int iio_read_max_channel_raw(struct iio_channel *chan, int *val); * For ranges, three vals are always returned; min, step and max. * For lists, all the possible values are enumerated. * - * Note raw available values from iio channels are in adc counts and - * hence scale will need to be applied if standard units are required. + * Note, if standard units are required, raw available values from iio + * channels need the offset (default 0) and scale (default 1) to be applied + * as (raw + offset) * scale. */ int iio_read_avail_channel_raw(struct iio_channel *chan, const int **vals, int *length);