From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 683F94C92; Sun, 22 Jun 2025 15:01:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750604464; cv=none; b=F3lmw4EOR4oHigOlQxsJtRgirPyEFYPgiR8kFxZDN/X7gZgHpUMlTp29ZJd39AfmmUr0W+iAam6wv4r9acmBtgBH3B3G2e/3J1j6sTns/LuyR8LXiXpBi0G3k4e5yRk0fkvpK831j9RYi1IUykEtHc5NONolYhwt7Ucmp2nIND0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750604464; c=relaxed/simple; bh=sJ2/YKvAq4zAkGzGocx1GG/np9WXkdppXLhIs/TekLw=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Vhd+D7IipNjmhUSGdsp3hmyzOc/VNHp+sJIgqowbxeqYxD8SG2og31zm7b8Jw108Syalqzygc8MJy0s0l5Ygcxh46saotSZpcvTWFqjwNy30hkJjnT4y9Yyjwh9NXAcTgfOii9j7RvG6KRVvxJLrDihDjw9TKIIp+ic0ZF3UPes= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=knJEdRzy; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="knJEdRzy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BE509C4CEE3; Sun, 22 Jun 2025 15:00:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1750604464; bh=sJ2/YKvAq4zAkGzGocx1GG/np9WXkdppXLhIs/TekLw=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=knJEdRzyKcdSZg9qK7QOMZcVbTnVd3l2qnWWxKbHoQqIeX+1sPUnZQ2QErD75yEAw b+6BRShnIJczJeBSOPxMOCrWPJBslMT56o/MDDP2QB416XuGRX9fY0IBfTfW1uDi5B m/aBVlfPNVLLoo/RwXceA5n6CmH4a5+Hx3+/l1mlO4I34Qt2e0wFNXX473rDQDbXo/ pFaMePkF7DUqh67oBBomB7EolbdGZE2VMKvQkZXcsTRLYLRHjhwXoWLLx7bxB7VKx4 PElydmi67/Lzcy+eI0f+1FNRtP6q0/rbnP8PQ0xHDkpw9RupsPaypu8X2qnTE2IcJk phqlSclQ17nrQ== Date: Sun, 22 Jun 2025 16:00:54 +0100 From: Jonathan Cameron To: David Lechner Cc: Michael Hennerich , Nuno =?UTF-8?B?U8Oh?= , Andy Shevchenko , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Mark Brown , linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-spi@vger.kernel.org Subject: Re: [PATCH 8/9] iio: adc: ad_sigma_delta: add SPI offload support Message-ID: <20250622160054.31cc5103@jic23-huawei> In-Reply-To: <20250620-iio-adc-ad7173-add-spi-offload-support-v1-8-0766f6297430@baylibre.com> References: <20250620-iio-adc-ad7173-add-spi-offload-support-v1-0-0766f6297430@baylibre.com> <20250620-iio-adc-ad7173-add-spi-offload-support-v1-8-0766f6297430@baylibre.com> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.48; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Fri, 20 Jun 2025 17:20:14 -0500 David Lechner wrote: > Add SPI offload support to the ad_sigma_delta module. > > When the SPI controller has SPI offload capabilities, the module will > now use that for buffered reads instead of the RDY interrupt trigger. > > Drivers that use the ad_sigma_delta module will have to opt into this > by setting supports_spi_offload since each driver will likely need > additional changes before SPI offload can be used. This will allow us > to gradually enable SPI offload support for each driver. > > Signed-off-by: David Lechner A few queries inline that again are more about the original code than what you change here. Jonathan > --- > drivers/iio/adc/ad_sigma_delta.c | 160 +++++++++++++++++++++++---------- > include/linux/iio/adc/ad_sigma_delta.h | 14 +++ > 2 files changed, 129 insertions(+), 45 deletions(-) > > diff --git a/drivers/iio/adc/ad_sigma_delta.c b/drivers/iio/adc/ad_sigma_delta.c > index a9b97f5d4107a2e1bb74877d30403445e9b04a44..449b0756be96d3f864a6e7f070467ad7311bf7d5 100644 > --- a/drivers/iio/adc/ad_sigma_delta.c > +++ b/drivers/iio/adc/ad_sigma_delta.c > @@ -14,11 +14,13 @@ > #include > #include > #include > +#include > #include > #include > #include > > #include > +#include > #include > #include > #include > @@ -460,8 +462,7 @@ static int ad_sd_buffer_postenable(struct iio_dev *indio_dev) > struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); > const struct iio_scan_type *scan_type = &indio_dev->channels[0].scan_type; > struct spi_transfer *xfer = sigma_delta->sample_xfer; > - unsigned int i, slot, samples_buf_size; > - unsigned int channel, scan_size; > + unsigned int i, slot, channel; > u8 *samples_buf; > int ret; > > @@ -489,23 +490,33 @@ static int ad_sd_buffer_postenable(struct iio_dev *indio_dev) > sigma_delta->active_slots = slot; > sigma_delta->current_slot = 0; > > - if (sigma_delta->active_slots > 1) { > - ret = ad_sigma_delta_append_status(sigma_delta, true); > - if (ret) > - return ret; > - } > + if (ad_sigma_delta_has_spi_offload(sigma_delta)) { > + xfer[1].offload_flags = SPI_OFFLOAD_XFER_RX_STREAM; > + xfer[1].bits_per_word = scan_type->realbits; > + xfer[1].len = spi_bpw_to_bytes(scan_type->realbits); > + } else { > + unsigned int samples_buf_size, scan_size; > > - samples_buf_size = ALIGN(slot * scan_type->storagebits, 8); > - samples_buf_size += sizeof(int64_t); > - samples_buf = devm_krealloc(&sigma_delta->spi->dev, sigma_delta->samples_buf, > - samples_buf_size, GFP_KERNEL); > - if (!samples_buf) > - return -ENOMEM; > + if (sigma_delta->active_slots > 1) { > + ret = ad_sigma_delta_append_status(sigma_delta, true); > + if (ret) > + return ret; > + } > > - sigma_delta->samples_buf = samples_buf; > - scan_size = BITS_TO_BYTES(scan_type->realbits + scan_type->shift); > - xfer[1].rx_buf = &sigma_delta->rx_buf[scan_size == 3 ? 1 : 0]; > - xfer[1].len = scan_size + (sigma_delta->status_appended ? 1 : 0); > + samples_buf_size = ALIGN(slot * scan_type->storagebits, 8); The code I queried earlier is moved here, so make sure to carry through any changes if it is indeed wrong! > + samples_buf_size += sizeof(int64_t); > + samples_buf = devm_krealloc(&sigma_delta->spi->dev, > + sigma_delta->samples_buf, > + samples_buf_size, GFP_KERNEL); > + if (!samples_buf) > + return -ENOMEM; > + > + sigma_delta->samples_buf = samples_buf; > + scan_size = BITS_TO_BYTES(scan_type->realbits + scan_type->shift); > + > + xfer[1].rx_buf = &sigma_delta->rx_buf[scan_size == 3 ? 1 : 0]; > + xfer[1].len = scan_size + (sigma_delta->status_appended ? 1 : 0); > + } > xfer[1].cs_change = 1; > > if (sigma_delta->info->has_registers) { > @@ -670,7 +700,8 @@ static irqreturn_t ad_sd_data_rdy_trig_poll(int irq, void *private) > if ((!sigma_delta->rdy_gpiod || gpiod_get_value(sigma_delta->rdy_gpiod)) && > ad_sd_disable_irq(sigma_delta)) { > complete(&sigma_delta->completion); > - iio_trigger_poll(sigma_delta->trig); > + if (sigma_delta->trig) Is this defensive or can we actually get here with out a trigger? I would have thought in the offload case (so no trigger here) we'd not call this function at all. Mind you, can't we get here with no trigger when doing a calibration or simple read normally? > + iio_trigger_poll(sigma_delta->trig); > > return IRQ_HANDLED; > }