From: Alexandru Ardelean <alexandru.ardelean@analog.com>
To: <linux-kernel@vger.kernel.org>, <linux-iio@vger.kernel.org>
Cc: <lars@metafoo.de>, <Michael.Hennerich@analog.com>,
<jic23@kernel.org>, <nuno.sa@analog.com>,
<dragos.bogdan@analog.com>,
Alexandru Ardelean <alexandru.ardelean@analog.com>
Subject: [PATCH v3 6/6] iio: buffer-dma: add support for cyclic DMA transfers
Date: Fri, 19 Feb 2021 14:40:12 +0200 [thread overview]
Message-ID: <20210219124012.92897-7-alexandru.ardelean@analog.com> (raw)
In-Reply-To: <20210219124012.92897-1-alexandru.ardelean@analog.com>
From: Lars-Peter Clausen <lars@metafoo.de>
This change adds support for cyclic DMA transfers using the IIO buffer DMA
infrastructure.
To do this, userspace must set the IIO_BUFFER_BLOCK_FLAG_CYCLIC flag on the
block when enqueueing them via the ENQUEUE_BLOCK ioctl().
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
---
.../buffer/industrialio-buffer-dmaengine.c | 24 ++++++++++++-------
include/uapi/linux/iio/buffer.h | 1 +
2 files changed, 17 insertions(+), 8 deletions(-)
diff --git a/drivers/iio/buffer/industrialio-buffer-dmaengine.c b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
index 65458a6cc81a..39cc230c7991 100644
--- a/drivers/iio/buffer/industrialio-buffer-dmaengine.c
+++ b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
@@ -82,14 +82,22 @@ static int iio_dmaengine_buffer_submit_block(struct iio_dma_buffer_queue *queue,
direction = dmaengine_buffer->is_tx ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
- desc = dmaengine_prep_slave_single(dmaengine_buffer->chan,
- block->phys_addr, block->block.bytes_used, direction,
- DMA_PREP_INTERRUPT);
- if (!desc)
- return -ENOMEM;
-
- desc->callback_result = iio_dmaengine_buffer_block_done;
- desc->callback_param = block;
+ if (block->block.flags & IIO_BUFFER_BLOCK_FLAG_CYCLIC) {
+ desc = dmaengine_prep_dma_cyclic(dmaengine_buffer->chan,
+ block->phys_addr, block->block.bytes_used,
+ block->block.bytes_used, direction, 0);
+ if (!desc)
+ return -ENOMEM;
+ } else {
+ desc = dmaengine_prep_slave_single(dmaengine_buffer->chan,
+ block->phys_addr, block->block.bytes_used, direction,
+ DMA_PREP_INTERRUPT);
+ if (!desc)
+ return -ENOMEM;
+
+ desc->callback_result = iio_dmaengine_buffer_block_done;
+ desc->callback_param = block;
+ }
cookie = dmaengine_submit(desc);
if (dma_submit_error(cookie))
diff --git a/include/uapi/linux/iio/buffer.h b/include/uapi/linux/iio/buffer.h
index 4e4ee9befea1..1bde508fe1b9 100644
--- a/include/uapi/linux/iio/buffer.h
+++ b/include/uapi/linux/iio/buffer.h
@@ -33,6 +33,7 @@ struct iio_buffer_block_alloc_req {
/* A function will be assigned later for BIT(0) */
#define IIO_BUFFER_BLOCK_FLAG_RESERVED (1 << 0)
+#define IIO_BUFFER_BLOCK_FLAG_CYCLIC (1 << 1)
/**
* struct iio_buffer_block - Descriptor for a single IIO block
--
2.27.0
next prev parent reply other threads:[~2021-02-19 12:42 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-19 12:40 [PATCH v3 0/6] iio: Add output buffer support Alexandru Ardelean
2021-02-19 12:40 ` [PATCH v3 1/6] " Alexandru Ardelean
2021-02-19 12:40 ` [PATCH v3 2/6] iio: kfifo-buffer: " Alexandru Ardelean
2021-02-19 12:40 ` [PATCH v3 3/6] iio: triggered-buffer: extend support to configure output buffers Alexandru Ardelean
2021-02-19 12:40 ` [PATCH v3 4/6] iio: buffer-dma: Allow to provide custom buffer ops Alexandru Ardelean
2021-02-19 12:40 ` [PATCH v3 5/6] iio: buffer-dma: Add output buffer support Alexandru Ardelean
2021-02-19 12:40 ` Alexandru Ardelean [this message]
2021-02-21 12:09 ` [PATCH v3 6/6] iio: buffer-dma: add support for cyclic DMA transfers Jonathan Cameron
2021-02-23 6:34 ` Alexandru Ardelean
2021-02-21 12:01 ` [PATCH v3 0/6] iio: Add output buffer support Jonathan Cameron
2021-03-05 8:57 ` Hennerich, Michael
2021-03-06 17:34 ` Jonathan Cameron
2021-03-08 10:07 ` Sa, Nuno
2021-03-08 11:52 ` Jonathan Cameron
2021-03-08 13:00 ` Sa, Nuno
2021-03-08 13:17 ` Sa, Nuno
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