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Wed, 4 Jun 2025 15:38:04 -0400 Received: from ASHBMBX8.ad.analog.com (10.64.17.5) by ASHBMBX8.ad.analog.com (10.64.17.5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1748.10; Wed, 4 Jun 2025 15:38:04 -0400 Received: from zeus.spd.analog.com (10.66.68.11) by ashbmbx8.ad.analog.com (10.64.17.5) with Microsoft SMTP Server id 15.2.1748.10 via Frontend Transport; Wed, 4 Jun 2025 15:38:04 -0400 Received: from JSANTO12-L01.ad.analog.com ([10.65.60.206]) by zeus.spd.analog.com (8.15.1/8.15.1) with ESMTP id 554Jbn6L014372; Wed, 4 Jun 2025 15:37:51 -0400 From: Jonathan Santos To: , , , CC: Jonathan Santos , , , , , , , , , , , , , , , Subject: [PATCH v10 12/12] iio: adc: ad7768-1: add low pass -3dB cutoff attribute Date: Wed, 4 Jun 2025 16:37:49 -0300 Message-ID: X-Mailer: git-send-email 2.34.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-gpio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ADIRuleOP-NewSCL: Rule Triggered X-Proofpoint-GUID: P97-NGToECrFgox5PbUEm23MwEChibJJ X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUwNjA0MDE1NSBTYWx0ZWRfXwMQtq3SCyKku PpZJm3D4Vuk7HOcUSgSv/wsHSYFApnuceQwrpDlGKTjdyxzCU6qeqbHVmU1zBq88pHPJniRXNwQ zPdCB0oeA9udBqkZ6hUTq4cFgNIHOGX1PrBbrtzyRy18FZAY5VogmGpiX/RcPdkAtyf1rGaKPd7 +AbOvlnkyeOv2t0LIN9YkV0a9P/BiECkF6r3vu1TkEXiPyGyAgPIWZdSvfAeHMpM4oEQ6e73+Kq LYsHkUMWW4b30JVkC8wU9pwJNmTNC3Jp8HPMT/cL5gH3t4N4oce+Zfqg9hCZE3kl84OOiERjSrI vjZ9F3JKMZpC6ZKs3nKH7vL7iMmbeNZNo+ErhWksONSFLUeck0nYijFO03AGQbIf17gdVhm2qCr H3dmQPWW/tyaCnDROIpkGk5admXbomAJCZB1zG1R2lbMZfZo9K+U/LBc/W3AyijKjsgMgcvX X-Proofpoint-ORIG-GUID: P97-NGToECrFgox5PbUEm23MwEChibJJ X-Authority-Analysis: v=2.4 cv=Fv4F/3rq c=1 sm=1 tr=0 ts=6840a09d cx=c_pps a=3WNzaoukacrqR9RwcOSAdA==:117 a=3WNzaoukacrqR9RwcOSAdA==:17 a=6IFa9wvqVegA:10 a=gAnH3GRIAAAA:8 a=IpJZQVW2AAAA:8 a=UvUlGJLpmzXXuVQgGPIA:9 a=IawgGOuG5U0WyFbmm1f5:22 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1099,Hydra:6.0.736,FMLib:17.12.80.40 definitions=2025-06-04_04,2025-06-03_02,2025-03-28_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 impostorscore=0 suspectscore=0 mlxlogscore=999 spamscore=0 malwarescore=0 phishscore=0 clxscore=1015 lowpriorityscore=0 priorityscore=1501 bulkscore=0 mlxscore=0 classifier=spam authscore=0 authtc=n/a authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.19.0-2505280000 definitions=main-2506040155 Ad7768-1 has a different -3db frequency multiplier depending on the filter type configured. The cutoff frequency also varies according to the current ODR. Add a readonly low pass -3dB frequency cutoff attribute to clarify to the user which bandwidth is being allowed depending on the filter configurations. Reviewed-by: Marcelo Schmitt Reviewed-by: David Lechner Signed-off-by: Jonathan Santos --- v10 Changes: * None v9 Changes: * Rearraged new BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY) to make the diff look cleaner. v8 Changes: * None v7 Changes: * None v6 Changes: * None v5 Changes: * None v4 Changes: * None v3 Changes: * None v2 Changes: * New patch in v2. --- drivers/iio/adc/ad7768-1.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/drivers/iio/adc/ad7768-1.c b/drivers/iio/adc/ad7768-1.c index 8c56b7243211..475d3e1b55ec 100644 --- a/drivers/iio/adc/ad7768-1.c +++ b/drivers/iio/adc/ad7768-1.c @@ -152,6 +152,17 @@ enum ad7768_scan_type { AD7768_SCAN_TYPE_HIGH_SPEED, }; +/* + * -3dB cutoff frequency multipliers (relative to ODR) for + * each filter type. Values are multiplied by 1000. + */ +static const int ad7768_filter_3db_odr_multiplier[] = { + [AD7768_FILTER_SINC5] = 204, + [AD7768_FILTER_SINC3] = 262, + [AD7768_FILTER_SINC3_REJ60] = 262, + [AD7768_FILTER_WIDEBAND] = 433, +}; + static const int ad7768_mclk_div_rates[] = { 16, 8, 4, 2, }; @@ -746,6 +757,7 @@ static const struct iio_chan_spec ad7768_channels[] = { .type = IIO_VOLTAGE, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY) | BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), .info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), @@ -766,7 +778,7 @@ static int ad7768_read_raw(struct iio_dev *indio_dev, { struct ad7768_state *st = iio_priv(indio_dev); const struct iio_scan_type *scan_type; - int scale_uv, ret; + int scale_uv, ret, temp; scan_type = iio_get_current_scan_type(indio_dev, chan); if (IS_ERR(scan_type)) @@ -804,6 +816,12 @@ static int ad7768_read_raw(struct iio_dev *indio_dev, case IIO_CHAN_INFO_OVERSAMPLING_RATIO: *val = st->oversampling_ratio; + return IIO_VAL_INT; + + case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: + temp = st->samp_freq * ad7768_filter_3db_odr_multiplier[st->filter_type]; + *val = DIV_ROUND_CLOSEST(temp, 1000); + return IIO_VAL_INT; }