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dmaengine: Add devm_dma_request_chan() 

Expand the arsenal of devm functions for DMA devices, this time for
requesting channels.

Signed-off-by: Bence Csókás <csokas.bence@prolan.hu>
Link: https://lore.kernel.org/r/20250610082256.400492-2-csokas.bence@prolan.hu
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Bence Csókás 2025-06-10 10:22:53 +02:00 committed by Vinod Koul
parent 19272b37aa
commit 08bf1663c2
2 changed files with 37 additions and 0 deletions
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30
drivers/dma/dmaengine.c
View File

@ -926,6 +926,36 @@ void dma_release_channel(struct dma_chan *chan)
}
EXPORT_SYMBOL_GPL(dma_release_channel);
static void dmaenginem_release_channel(void *chan)
{
dma_release_channel(chan);
}
/**
* devm_dma_request_chan - try to allocate an exclusive slave channel
* @dev: pointer to client device structure
* @name: slave channel name
*
* Returns pointer to appropriate DMA channel on success or an error pointer.
*
* The operation is managed and will be undone on driver detach.
*/
struct dma_chan *devm_dma_request_chan(struct device *dev, const char *name)
{
struct dma_chan *chan = dma_request_chan(dev, name);
int ret = 0;
if (!IS_ERR(chan))
ret = devm_add_action_or_reset(dev, dmaenginem_release_channel, chan);
if (ret)
return ERR_PTR(ret);
return chan;
}
EXPORT_SYMBOL_GPL(devm_dma_request_chan);
/**
* dmaengine_get - register interest in dma_channels
*/

7
include/linux/dmaengine.h
View File

@ -1524,6 +1524,7 @@ struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
struct dma_chan *dma_request_chan(struct device *dev, const char *name);
struct dma_chan *dma_request_chan_by_mask(const dma_cap_mask_t *mask);
struct dma_chan *devm_dma_request_chan(struct device *dev, const char *name);
void dma_release_channel(struct dma_chan *chan);
int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps);
@ -1560,6 +1561,12 @@ static inline struct dma_chan *dma_request_chan_by_mask(
{
return ERR_PTR(-ENODEV);
}
static inline struct dma_chan *devm_dma_request_chan(struct device *dev, const char *name)
{
return ERR_PTR(-ENODEV);
}
static inline void dma_release_channel(struct dma_chan *chan)
{
}