Hi Maxime,
Thank you for the patch.
On Tuesday 28 October 2014 22:25:25 Maxime Ripard wrote:
> dma_slave_caps is very important to the generic layers that might interact
> with dmaengine, such as ASoC. Unfortunately, it has been added as yet
> another dma_device callback, and most of the existing drivers haven't
> implemented it, reducing its reliability.
>
> Introduce a generic behaviour to implement this, that rely on both the split
> of device_control to derive which functions are supported and on new
> variables to be set in the dma_device structure.
>
> These variables holds what used to be the capabilities, that were set
> per-channel. However, this proved to be a bit overkill, since every driver
> filling these so far were hardcoding it, disregarding which channel was
> actually given.
>
> Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
Acked-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
You might want to consider adding "dmaengine: Move dma_get_slave_caps()
implementation to dmaengine.c" to this series.
> ---
> include/linux/dmaengine.h | 41 +++++++++++++++++++++++++++++++++++++----
> 1 file changed, 37 insertions(+), 4 deletions(-)
>
> diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
> index b0efc805937a..be9e60aa8f5e 100644
> --- a/include/linux/dmaengine.h
> +++ b/include/linux/dmaengine.h
> @@ -593,6 +593,14 @@ struct dma_tx_state {
> * @fill_align: alignment shift for memset operations
> * @dev_id: unique device ID
> * @dev: struct device reference for dma mapping api
> + * @src_addr_widths: bit mask of src addr widths the device supports
> + * @dst_addr_widths: bit mask of dst addr widths the device supports
> + * @directions: bit mask of slave direction the device supports since
> + * the enum dma_transfer_direction is not defined as bits for
> + * each type of direction, the dma controller should fill (1 <<
> + * <TYPE>) and same should be checked by controller as well
> + * @residue_granularity: granularity of the transfer residue reported
> + * by tx_status
> * @device_alloc_chan_resources: allocate resources and return the
> * number of allocated descriptors
> * @device_free_chan_resources: release DMA channel's resources
> @@ -642,6 +650,11 @@ struct dma_device {
> int dev_id;
> struct device *dev;
>
> + u32 src_addr_widths;
> + u32 dst_addr_widths;
> + u32 directions;
> + enum dma_residue_granularity residue_granularity;
> +
> int (*device_alloc_chan_resources)(struct dma_chan *chan);
> void (*device_free_chan_resources)(struct dma_chan *chan);
>
> @@ -783,17 +796,37 @@ static inline struct dma_async_tx_descriptor
> *dmaengine_prep_dma_sg(
>
> static inline int dma_get_slave_caps(struct dma_chan *chan, struct
> dma_slave_caps *caps) {
> + struct dma_device *device;
> +
> if (!chan || !caps)
> return -EINVAL;
>
> + device = chan->device;
> +
> /* check if the channel supports slave transactions */
> - if (!test_bit(DMA_SLAVE, chan->device->cap_mask.bits))
> + if (!test_bit(DMA_SLAVE, device->cap_mask.bits))
> + return -ENXIO;
> +
> + if (device->device_slave_caps)
> + return device->device_slave_caps(chan, caps);
> +
> + /*
> + * Check whether it reports it uses the generic slave
> + * capabilities, if not, that means it doesn't support any
> + * kind of slave capabilities reporting.
> + */
> + if (!device->directions)
> return -ENXIO;
>
> - if (chan->device->device_slave_caps)
> - return chan->device->device_slave_caps(chan, caps);
> + caps->src_addr_widths = device->src_addr_widths;
> + caps->dst_addr_widths = device->dst_addr_widths;
> + caps->directions = device->directions;
> + caps->residue_granularity = device->residue_granularity;
> +
> + caps->cmd_pause = !!device->device_pause;
> + caps->cmd_terminate = !!device->device_terminate_all;
>
> - return -ENXIO;
> + return 0;
> }
>
> static inline int dmaengine_terminate_all(struct dma_chan *chan)
--
Regards,
Laurent Pinchart
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