include/dmac/dma_controller.h File Reference

DMA Controller Interface. More...

#include <dma.h>
#include <slist.h>
#include <types.h>
#include <buffer.h>
#include <chip/dma_controller.h>

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Data Structures
struct	dmac_request
	Asynchronous DMA request. More...
struct	dmac_channel
	A DMA Controller Channel. More...
struct	dma_controller
	A DMA Controller. More...
Enumerations
enum	dmac_reg_width { DMAC_REG_WIDTH_8BIT = 0, DMAC_REG_WIDTH_16BIT = 1, DMAC_REG_WIDTH_32BIT = 2 }
	Peripheral register width. More...
enum	dmac_burst_length {   DMAC_BURST_LENGTH_1 = 0, DMAC_BURST_LENGTH_4 = 1, DMAC_BURST_LENGTH_8 = 2, DMAC_BURST_LENGTH_16 = 3,   DMAC_BURST_LENGTH_32 = 4 }
	Transaction burst length. More...
Functions
static struct dmac_channel *	dmac_alloc_channel (struct dma_controller *dmac, enum dmac_periph_id rx_periph, enum dmac_periph_id tx_periph, phys_addr_t rx_reg_addr, phys_addr_t tx_reg_addr)
	Allocate a channel on a given DMA Controller.
static void	dmac_free_channel (struct dma_controller *dmac, struct dmac_channel *chan)
	Free a previously allocated DMA Controller channel.
static void	dmac_chan_submit_request (struct dmac_channel *chan, struct dmac_request *req)
	Submit a DMA transfer request.
static void	dmac_chan_reset (struct dmac_channel *chan)
	Reset a DMA channel.
static void	dmac_req_init (struct dmac_request *req)
	Initialize a DMA request.
static void	dmac_req_add_buffer (struct dmac_request *req, struct buffer *buf)
	Assign the buffer buf to the DMA request req.

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Detailed Description

DMA Controller Interface.

A DMA Controller (DMAC) is a device capable of doing data transfers between memory and a peripheral device without CPU intervention. Some controllers also support memory-to-memory transfers.

• Compiler: IAR EWAVR32 and GNU GCC for AVR32
• Supported devices: All devices
• AppNote:

Author:

Atmel Corporation: http://www.atmel.com
Support and FAQ: http://support.atmel.no/

Definition in file dma_controller.h.

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Enumeration Type Documentation

enum dmac_burst_length

Transaction burst length.

Enumerator:

DMAC_BURST_LENGTH_1	1 item
DMAC_BURST_LENGTH_4	4 items
DMAC_BURST_LENGTH_8	8 items
DMAC_BURST_LENGTH_16	16 items
DMAC_BURST_LENGTH_32	32 items

Definition at line 71 of file dma_controller.h.

enum dmac_reg_width

Peripheral register width.

Enumerator:

DMAC_REG_WIDTH_8BIT	8 bits
DMAC_REG_WIDTH_16BIT	16 bits
DMAC_REG_WIDTH_32BIT	32 bits

Definition at line 62 of file dma_controller.h.

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Function Documentation

static struct dmac_channel* dmac_alloc_channel	(	struct dma_controller *	dmac,
		enum dmac_periph_id	rx_periph,
		enum dmac_periph_id	tx_periph,
		phys_addr_t	rx_reg_addr,
		phys_addr_t	tx_reg_addr
	)			[static, read]

Allocate a channel on a given DMA Controller.

Parameters:

	dmac	The DMA Controller on which to allocate a channel
	rx_periph	Perpiheral ID to use when receiving data, or DMAC_PERIPH_NONE if the channel is to be used for TX only.
	tx_periph	Perpiheral ID to use when transmitting data, or DMAC_PERIPH_NONE if the channel is to be used for RX only.
	rx_reg_addr	Physical address of the Receive Data Register
	tx_reg_addr	Physical address of the Transmit Data Register

Returns:

A DMA channel object which can be used to submit DMA transfer requests, or NULL if no channels are available.

Definition at line 146 of file dma_controller.h.

References dma_controller::alloc_chan.

static void dmac_chan_reset

(

struct dmac_channel *

chan

)

[inline, static]

Reset a DMA channel.

This function stops the DMA Controller and terminates all pending requests.

Parameters:

chan

The Channel to be reset

Definition at line 191 of file dma_controller.h.

References dmac_channel::reset.

static void dmac_chan_submit_request	(	struct dmac_channel *	chan,
		struct dmac_request *	req
	)			[inline, static]

Submit a DMA transfer request.

This function does not return any value indicating if the request was successful; set up a req_done() callback and check dmac_request::status to verify the status of the request.

Parameters:

	chan	The channel on which to submit the request
	req	The request to be submitted

Definition at line 178 of file dma_controller.h.

References dmac_channel::submit_req.

Referenced by aes_submit_request(), and sdmmc_mcihost_load_data().

static void dmac_free_channel	(	struct dma_controller *	dmac,
		struct dmac_channel *	chan
	)			[inline, static]

Free a previously allocated DMA Controller channel.

Parameters:

	dmac	The DMA Controller from which the channel was allocated
	chan	The Channel to be freed

Definition at line 162 of file dma_controller.h.

References dma_controller::free_chan.

static void dmac_req_add_buffer	(	struct dmac_request *	req,
		struct buffer *	buf
	)			[inline, static]

Assign the buffer buf to the DMA request req.

buf will be transfered after any previously assigned buffers.

Definition at line 210 of file dma_controller.h.

References dmac_request::buf_list, buffer::node, and slist_insert_tail().

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static void dmac_req_init

(

struct dmac_request *

req

)

[inline, static]

Initialize a DMA request.

Parameters:

req

The request to be initialized

Definition at line 200 of file dma_controller.h.

References dmac_request::buf_list, and slist_init().

Referenced by sdmmc_mcihost_init().

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