Commit cb8cea51 authored by Maxime Ripard's avatar Maxime Ripard Committed by Vinod Koul
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dmaengine: Create a generic dma_slave_caps callback 



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: default avatarMaxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarVinod Koul <vinod.koul@intel.com>
parent 4f8ef9f4

include/linux/dmaengine.h

+37 −4
Original line number Diff line number Diff line
@@ -594,6 +594,14 @@ 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
@@ -643,6 +651,11 @@ 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);
@@ -784,17 +797,37 @@ 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 (chan->device->device_slave_caps)

		return chan->device->device_slave_caps(chan, caps);

	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;



	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 0;

}



static inline int dmaengine_terminate_all(struct dma_chan *chan)

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