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From 94a73e30dfe6722e9f4ef19f7892901d7d00eab1 Mon Sep 17 00:00:00 2001
From: Maxime Ripard <maxime.ripard@free-electrons.com>
Date: Mon, 17 Nov 2014 14:42:00 +0100
Subject: [PATCH] dmaengine: Introduce a device_config callback
The fact that the channel configuration is done in device_control is rather
misleading, since it's not really advertised as such, plus, the fact that the
framework exposes a function of its own makes it not really intuitive, while
we're losing the type checking whenever we pass that unsigned long argument.
Add a device_config callback to dma_device, with a fallback on the old
behaviour for now for existing drivers to opt in.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
---
include/linux/dmaengine.h | 8 ++++++++
1 file changed, 8 insertions(+)
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -607,6 +607,8 @@ struct dma_tx_state {
* The function takes a buffer of size buf_len. The callback function will
* be called after period_len bytes have been transferred.
* @device_prep_interleaved_dma: Transfer expression in a generic way.
+ * @device_config: Pushes a new configuration to a channel, return 0 or an error
+ * code
* @device_control: manipulate all pending operations on a channel, returns
* zero or error code
* @device_tx_status: poll for transaction completion, the optional
@@ -673,6 +675,9 @@ struct dma_device {
struct dma_async_tx_descriptor *(*device_prep_interleaved_dma)(
struct dma_chan *chan, struct dma_interleaved_template *xt,
unsigned long flags);
+
+ int (*device_config)(struct dma_chan *chan,
+ struct dma_slave_config *config);
int (*device_control)(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
unsigned long arg);
@@ -696,6 +701,9 @@ static inline int dmaengine_device_contr
static inline int dmaengine_slave_config(struct dma_chan *chan,
struct dma_slave_config *config)
{
+ if (chan->device->device_config)
+ return chan->device->device_config(chan, config);
+
return dmaengine_device_control(chan, DMA_SLAVE_CONFIG,
(unsigned long)config);
}
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