DMA

PowerVR DMA driver More...

Topics
	Transfer Modes
	Transfer modes with TA/PVR DMA and Store Queues

Typedefs
typedef void(*	pvr_dma_callback_t) (void *data)
	PVR DMA interrupt callback type.

Functions
int	pvr_dma_transfer (const void *src, uintptr_t dest, size_t count, pvr_dma_type_t type, int block, pvr_dma_callback_t callback, void *cbdata)
	Perform a DMA transfer to the PVR RAM over 64-bit TA bus.
int	pvr_txr_load_dma (void *src, pvr_ptr_t dest, size_t count, int block, pvr_dma_callback_t callback, void *cbdata)
	Load a texture using TA DMA.
int	pvr_dma_load_ta (void *src, size_t count, int block, pvr_dma_callback_t callback, void *cbdata)
	Load vertex data to the TA using TA DMA.
int	pvr_dma_yuv_conv (void *src, size_t count, int block, pvr_dma_callback_t callback, void *cbdata)
	Load yuv data to the YUV converter using TA DMA.
int	pvr_dma_ready (void)
	Is PVR DMA is inactive?
void	pvr_dma_init (void)
	Initialize TA/PVR DMA.
void	pvr_dma_shutdown (void)
	Shut down TA/PVR DMA.

Detailed Description

PowerVR DMA driver

Typedef Documentation

pvr_dma_callback_t

typedef void(* pvr_dma_callback_t) (void *data)

PVR DMA interrupt callback type.

Functions that act as callbacks when DMA completes should be of this type. These functions will be called inside an interrupt context, so don't try to use anything that might stall.

Parameters

data	User data passed in to the pvr_dma_transfer() function.

Function Documentation

pvr_dma_init()

void pvr_dma_init

(

void

)

Initialize TA/PVR DMA.

pvr_dma_load_ta()

int pvr_dma_load_ta	(	void *	src,
		size_t	count,
		int	block,
		pvr_dma_callback_t	callback,
		void *	cbdata )

Load vertex data to the TA using TA DMA.

This is essentially a convenience wrapper for pvr_dma_transfer(), so all notes that apply to it also apply here.

Parameters

src	Where to copy from. Must be 32-byte aligned.
count	The number of bytes to copy. Must be a multiple of 32.
block	Non-zero if you want the function to block until the DMA completes.
callback	A function to call upon completion of the DMA.
cbdata	Data to pass to the callback function.

Return values

0	On success.
-1	On failure. Sets errno as appropriate.

Error Conditions:

EINPROGRESS - DMA already in progress
EFAULT - dest is not 32-byte aligned
EIO - I/O error

pvr_dma_ready()

int pvr_dma_ready

(

void

)

Is PVR DMA is inactive?

Returns

Non-zero if there is no PVR DMA active, thus a DMA can begin or 0 if there is an active DMA.

pvr_dma_shutdown()

void pvr_dma_shutdown

(

void

)

Shut down TA/PVR DMA.

pvr_dma_transfer()

int pvr_dma_transfer	(	const void *	src,
		uintptr_t	dest,
		size_t	count,
		pvr_dma_type_t	type,
		int	block,
		pvr_dma_callback_t	callback,
		void *	cbdata )

Perform a DMA transfer to the PVR RAM over 64-bit TA bus.

This function copies a block of data to the PVR or its memory via DMA. There are all kinds of constraints that must be fulfilled to actually do this, so make sure to read all the fine print with the parameter list.

If a callback is specified, it will be called in an interrupt context, so keep that in mind in writing the callback.

Parameters

src	Where to copy from. Must be 32-byte aligned.
dest	Where to copy to. Must be 32-byte aligned.
count	The number of bytes to copy. Must be a multiple of 32.
type	The type of DMA transfer to do (see list of modes).
block	Non-zero if you want the function to block until the DMA completes.
callback	A function to call upon completion of the DMA.
cbdata	Data to pass to the callback function.

Return values

0	On success.
-1	On failure. Sets errno as appropriate.

Error Conditions:

EINPROGRESS - DMA already in progress
EFAULT - dest is not 32-byte aligned
EIO - I/O error

See also

pvr_dma_type_t

pvr_dma_yuv_conv()

int pvr_dma_yuv_conv	(	void *	src,
		size_t	count,
		int	block,
		pvr_dma_callback_t	callback,
		void *	cbdata )

Load yuv data to the YUV converter using TA DMA.

This is essentially a convenience wrapper for pvr_dma_transfer(), so all notes that apply to it also apply here.

Parameters

src	Where to copy from. Must be 32-byte aligned.
count	The number of bytes to copy. Must be a multiple of 32.
block	Non-zero if you want the function to block until the DMA completes.
callback	A function to call upon completion of the DMA.
cbdata	Data to pass to the callback function.

Return values

0	On success.
-1	On failure. Sets errno as appropriate.

Error Conditions:

EINPROGRESS - DMA already in progress
EFAULT - dest is not 32-byte aligned
EIO - I/O error

pvr_txr_load_dma()

int pvr_txr_load_dma	(	void *	src,
		pvr_ptr_t	dest,
		size_t	count,
		int	block,
		pvr_dma_callback_t	callback,
		void *	cbdata )

Load a texture using TA DMA.

This is essentially a convenience wrapper for pvr_dma_transfer(), so all notes that apply to it also apply here.

Parameters

src	Where to copy from. Must be 32-byte aligned.
dest	Where to copy to. Must be 32-byte aligned.
count	The number of bytes to copy. Must be a multiple of 32.
block	Non-zero if you want the function to block until the DMA completes.
callback	A function to call upon completion of the DMA.
cbdata	Data to pass to the callback function.

Return values

0	On success.
-1	On failure. Sets errno as appropriate.

Error Conditions:

EINPROGRESS - DMA already in progress
EFAULT - dest is not 32-byte aligned
EIO - I/O error