From: Sascha Hauer <s.hauer@pengutronix.de>
To: linux-kernel@vger.kernel.org
Cc: Linus Walleij <linus.ml.walleij@gmail.com>,
Dan Williams <dan.j.williams@intel.com>,
linux-arm-kernel@lists.infradead.org,
Sascha Hauer <s.hauer@pengutronix.de>,
Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Subject: [PATCH 1/3] dmaengine: add possibility for cyclic transfers
Date: Mon, 16 Aug 2010 13:07:48 +0200 [thread overview]
Message-ID: <1281956870-12463-2-git-send-email-s.hauer@pengutronix.de> (raw)
In-Reply-To: <1281956870-12463-1-git-send-email-s.hauer@pengutronix.de>
Cyclic transfers are useful for audio where a single buffer divided
in periods has to be transfered endlessly until stopped. After being
prepared the transfer is started using the dma_async_descriptor->tx_submit
function. dma_async_descriptor->callback is called after each period.
The transfer is stopped using the DMA_TERMINATE_ALL callback.
While being used for cyclic transfers the channel cannot be used
for other transfer types.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
---
drivers/dma/dmaengine.c | 2 ++
include/linux/dmaengine.h | 6 +++++-
2 files changed, 7 insertions(+), 1 deletions(-)
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 9d31d5e..e5e79ce 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -692,6 +692,8 @@ int dma_async_device_register(struct dma_device *device)
!device->device_prep_dma_interrupt);
BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) &&
!device->device_prep_slave_sg);
+ BUG_ON(dma_has_cap(DMA_CYCLIC, device->cap_mask) &&
+ !device->device_prep_dma_cyclic);
BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) &&
!device->device_control);
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index c61d4ca..0df7864 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -67,10 +67,11 @@ enum dma_transaction_type {
DMA_PRIVATE,
DMA_ASYNC_TX,
DMA_SLAVE,
+ DMA_CYCLIC,
};
/* last transaction type for creation of the capabilities mask */
-#define DMA_TX_TYPE_END (DMA_SLAVE + 1)
+#define DMA_TX_TYPE_END (DMA_CYCLIC + 1)
/**
@@ -478,6 +479,9 @@ struct dma_device {
struct dma_chan *chan, struct scatterlist *sgl,
unsigned int sg_len, enum dma_data_direction direction,
unsigned long flags);
+ struct dma_async_tx_descriptor *(*device_prep_dma_cyclic)(
+ struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
+ size_t period_len, enum dma_data_direction direction);
int (*device_control)(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
unsigned long arg);
--
1.7.1
next prev parent reply other threads:[~2010-08-16 11:08 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-16 11:07 [RFC] dmaengine: assorted patches and Freescale SDMA support Sascha Hauer
2010-08-16 11:07 ` Sascha Hauer [this message]
2010-08-16 11:56 ` [PATCH 1/3] dmaengine: add possibility for cyclic transfers Lothar Waßmann
2010-08-16 12:27 ` Linus Walleij
2010-08-16 12:32 ` Sascha Hauer
2010-08-16 12:22 ` Linus Walleij
2010-09-20 13:01 ` Sascha Hauer
2010-09-23 19:42 ` Dan Williams
2010-09-24 7:25 ` Sascha Hauer
2010-08-16 11:07 ` [PATCH 2/3] dmaengine: add wrapper functions for dmaengine Sascha Hauer
2010-08-23 7:17 ` Sascha Hauer
2010-09-20 13:02 ` Sascha Hauer
2010-09-23 19:53 ` Dan Williams
2010-09-24 7:25 ` Sascha Hauer
2010-09-24 15:45 ` Dan Williams
2010-08-16 11:07 ` [PATCH 3/3] dmaengine: Add Freescale i.MX SDMA support Sascha Hauer
2010-08-16 12:21 ` Linus Walleij
2010-08-16 14:15 ` Sascha Hauer
2010-08-17 4:36 ` Baruch Siach
2010-08-17 6:47 ` Sascha Hauer
2010-08-18 11:17 ` Philippe Rétornaz
2010-08-24 7:10 ` [PATCH 3/3 v3] " Sascha Hauer
2010-09-02 14:06 ` [PATCH 3/3] " Russell King - ARM Linux
2010-08-23 12:57 ` [PATCH 3/3 v2] " Sascha Hauer
2010-08-23 17:30 ` Linus Walleij
2010-08-24 6:58 ` Sascha Hauer
2010-08-23 17:48 ` Uwe Kleine-König
2010-08-28 15:18 ` Linus Walleij
2010-08-28 15:27 ` Marek Vasut
2010-08-28 16:18 ` Sascha Hauer
2010-08-28 16:30 ` Marek Vasut
2010-08-28 17:20 ` Sascha Hauer
2010-09-02 11:20 ` Russell King - ARM Linux
2010-08-29 12:35 ` Linus Walleij
2010-08-30 12:55 ` Sascha Hauer
2010-08-24 7:58 ` Lothar Waßmann
2010-08-24 15:01 ` Linus Walleij
2010-08-27 12:22 ` [PATCH 3/3 v3] " Sascha Hauer
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