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 DB3162D7BF for ; Sun, 24 Aug 2025 13:13:06 +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=1756041186; cv=none; b=Xhpw08lYhPSR10l2bf6O6V1ySNHrSs3eTVUA1wI2LDcwVxPhqISR9H6mSFjffdk4w2qsINa6XDDqJIYJXOYslY9Jm7ymNVBz9MXlfBuUNVb+LUKD5UtT724Wq4x4rI0ZwGarproTHES2PbfqxnA+cczOa0wzcWzNMpYvMjRTBdY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756041186; c=relaxed/simple; bh=GcGtUY9/ohflnanoWfhy5ik2ngXkam+ZyWgjVUhtIzg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=OFd4wd2gmCOL502920Yjg+9mSjtJTAvqw+/3yO9lmdWYQtLQPXSAgRR9+Wk6SYXM1CnzbOdF4AACYmTdEKuGTp40PmgI/kbs/6+U6mRqZWrQ5hO/qI2wzLBTnrhUY5pyQmRRFdnqAlpFFGg3K/wyh/A7aEi0cv9Gdy086PUGq08= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=hvbvvlNR; 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="hvbvvlNR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6651AC4CEEB; Sun, 24 Aug 2025 13:13:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756041186; bh=GcGtUY9/ohflnanoWfhy5ik2ngXkam+ZyWgjVUhtIzg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hvbvvlNRlNSRBAyLCVy5BMCovbZ3o8LppqQ6GVn8LuCqcyjsK2iT4p0444k0gRPhI ulnaRO6vFPfWUarg/KIRD8g8vbK3u8ydv4J2OK1xZfwdrhiXqd2n6+ibwWFWK5s9tI NuQ5CdUSvrHYDHAXUPNCQR0KPoNp79TonYMjVrgehVgj7Ik1goEUPTb4uBdX5ms74a FC9GXijpbRJB6s1aMnuXr+n8d07UWx3OoSYSlvcSi9Xo+ZuvS9ZYFKYb6hP0DKff3z phULTmUf5UneDrEez752a4vGs2jK8jJiz+RmrFi539hIvpDM4R9tFLx0MJfhD1A4w0 zOe7Gn3fx6mOw== From: Sasha Levin To: stable@vger.kernel.org Cc: David Lechner , =?UTF-8?q?Nuno=20S=C3=A1?= , Stable@vger.kernel.org, Jonathan Cameron , Sasha Levin Subject: [PATCH 6.1.y] iio: temperature: maxim_thermocouple: use DMA-safe buffer for spi_read() Date: Sun, 24 Aug 2025 09:13:03 -0400 Message-ID: <20250824131303.2806125-1-sashal@kernel.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <2025082300-collapse-wireless-5bdc@gregkh> References: <2025082300-collapse-wireless-5bdc@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: David Lechner [ Upstream commit ae5bc07ec9f73a41734270ef3f800c5c8a7e0ad3 ] Replace using stack-allocated buffers with a DMA-safe buffer for use with spi_read(). This allows the driver to be safely used with DMA-enabled SPI controllers. The buffer array is also converted to a struct with a union to make the usage of the memory in the buffer more clear and ensure proper alignment. Fixes: 1f25ca11d84a ("iio: temperature: add support for Maxim thermocouple chips") Signed-off-by: David Lechner Reviewed-by: Nuno Sá Link: https://patch.msgid.link/20250721-iio-use-more-iio_declare_buffer_with_ts-3-v2-1-0c68d41ccf6c@baylibre.com Cc: Signed-off-by: Jonathan Cameron [ iio_push_to_buffers_with_ts() => iio_push_to_buffers_with_timestamp() ] Signed-off-by: Sasha Levin --- drivers/iio/temperature/maxim_thermocouple.c | 26 ++++++++++++-------- 1 file changed, 16 insertions(+), 10 deletions(-) diff --git a/drivers/iio/temperature/maxim_thermocouple.c b/drivers/iio/temperature/maxim_thermocouple.c index 555a61e2f3fd..44fba61ccfe2 100644 --- a/drivers/iio/temperature/maxim_thermocouple.c +++ b/drivers/iio/temperature/maxim_thermocouple.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include #include @@ -122,8 +123,15 @@ struct maxim_thermocouple_data { struct spi_device *spi; const struct maxim_thermocouple_chip *chip; char tc_type; - - u8 buffer[16] __aligned(IIO_DMA_MINALIGN); + /* Buffer for reading up to 2 hardware channels. */ + struct { + union { + __be16 raw16; + __be32 raw32; + __be16 raw[2]; + }; + aligned_s64 timestamp; + } buffer __aligned(IIO_DMA_MINALIGN); }; static int maxim_thermocouple_read(struct maxim_thermocouple_data *data, @@ -131,18 +139,16 @@ static int maxim_thermocouple_read(struct maxim_thermocouple_data *data, { unsigned int storage_bytes = data->chip->read_size; unsigned int shift = chan->scan_type.shift + (chan->address * 8); - __be16 buf16; - __be32 buf32; int ret; switch (storage_bytes) { case 2: - ret = spi_read(data->spi, (void *)&buf16, storage_bytes); - *val = be16_to_cpu(buf16); + ret = spi_read(data->spi, &data->buffer.raw16, storage_bytes); + *val = be16_to_cpu(data->buffer.raw16); break; case 4: - ret = spi_read(data->spi, (void *)&buf32, storage_bytes); - *val = be32_to_cpu(buf32); + ret = spi_read(data->spi, &data->buffer.raw32, storage_bytes); + *val = be32_to_cpu(data->buffer.raw32); break; default: ret = -EINVAL; @@ -167,9 +173,9 @@ static irqreturn_t maxim_thermocouple_trigger_handler(int irq, void *private) struct maxim_thermocouple_data *data = iio_priv(indio_dev); int ret; - ret = spi_read(data->spi, data->buffer, data->chip->read_size); + ret = spi_read(data->spi, data->buffer.raw, data->chip->read_size); if (!ret) { - iio_push_to_buffers_with_timestamp(indio_dev, data->buffer, + iio_push_to_buffers_with_timestamp(indio_dev, &data->buffer, iio_get_time_ns(indio_dev)); } -- 2.50.1