On 22-12-24, 15:14, Bence Csókás wrote:
> Expand the arsenal of devm functions for DMA
> devices, this time for requesting channels.
Looks good, users for this?
>
> Signed-off-by: Bence Csókás <csokas.bence@xxxxxxxxx>
> ---
>
> Notes:
> Changes in v2:
> * add prototype to header
> * fix ERR_PTR() mixup
>
> drivers/dma/dmaengine.c | 30 ++++++++++++++++++++++++++++++
> include/linux/dmaengine.h | 7 +++++++
> 2 files changed, 37 insertions(+)
>
> diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
> index c1357d7f3dc6..02c29d26ac85 100644
> --- a/drivers/dma/dmaengine.c
> +++ b/drivers/dma/dmaengine.c
> @@ -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
> */
> diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
> index b137fdb56093..631519552c5a 100644
> --- a/include/linux/dmaengine.h
> +++ b/include/linux/dmaengine.h
> @@ -1521,6 +1521,7 @@ 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);
> @@ -1557,6 +1558,12 @@ 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)
> {
> }
> --
> 2.34.1
>
--
~Vinod
