forked from Minki/linux
85d988fcff
Add kernel-doc documentation for the EP93xx DMA memory to peripheral/peripheral to memory API. Signed-off-by: Ryan Mallon <ryan@bluewatersys.com> Acked-by: Mika Westerberg <mika.westerberg@iki.fi> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
150 lines
4.5 KiB
C
150 lines
4.5 KiB
C
/**
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* DOC: EP93xx DMA M2P memory to peripheral and peripheral to memory engine
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*
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* The EP93xx DMA M2P subsystem handles DMA transfers between memory and
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* peripherals. DMA M2P channels are available for audio, UARTs and IrDA.
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* See chapter 10 of the EP93xx users guide for full details on the DMA M2P
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* engine.
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*
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* See sound/soc/ep93xx/ep93xx-pcm.c for an example use of the DMA M2P code.
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*
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*/
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#ifndef __ASM_ARCH_DMA_H
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#define __ASM_ARCH_DMA_H
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#include <linux/list.h>
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#include <linux/types.h>
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/**
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* struct ep93xx_dma_buffer - Information about a buffer to be transferred
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* using the DMA M2P engine
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*
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* @list: Entry in DMA buffer list
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* @bus_addr: Physical address of the buffer
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* @size: Size of the buffer in bytes
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*/
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struct ep93xx_dma_buffer {
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struct list_head list;
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u32 bus_addr;
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u16 size;
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};
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/**
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* struct ep93xx_dma_m2p_client - Information about a DMA M2P client
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*
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* @name: Unique name for this client
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* @flags: Client flags
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* @cookie: User data to pass to callback functions
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* @buffer_started: Non NULL function to call when a transfer is started.
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* The arguments are the user data cookie and the DMA
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* buffer which is starting.
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* @buffer_finished: Non NULL function to call when a transfer is completed.
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* The arguments are the user data cookie, the DMA buffer
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* which has completed, and a boolean flag indicating if
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* the transfer had an error.
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*/
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struct ep93xx_dma_m2p_client {
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char *name;
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u8 flags;
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void *cookie;
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void (*buffer_started)(void *cookie,
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struct ep93xx_dma_buffer *buf);
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void (*buffer_finished)(void *cookie,
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struct ep93xx_dma_buffer *buf,
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int bytes, int error);
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/* private: Internal use only */
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void *channel;
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};
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/* DMA M2P ports */
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#define EP93XX_DMA_M2P_PORT_I2S1 0x00
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#define EP93XX_DMA_M2P_PORT_I2S2 0x01
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#define EP93XX_DMA_M2P_PORT_AAC1 0x02
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#define EP93XX_DMA_M2P_PORT_AAC2 0x03
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#define EP93XX_DMA_M2P_PORT_AAC3 0x04
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#define EP93XX_DMA_M2P_PORT_I2S3 0x05
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#define EP93XX_DMA_M2P_PORT_UART1 0x06
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#define EP93XX_DMA_M2P_PORT_UART2 0x07
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#define EP93XX_DMA_M2P_PORT_UART3 0x08
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#define EP93XX_DMA_M2P_PORT_IRDA 0x09
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#define EP93XX_DMA_M2P_PORT_MASK 0x0f
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/* DMA M2P client flags */
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#define EP93XX_DMA_M2P_TX 0x00 /* Memory to peripheral */
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#define EP93XX_DMA_M2P_RX 0x10 /* Peripheral to memory */
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/*
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* DMA M2P client error handling flags. See the EP93xx users guide
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* documentation on the DMA M2P CONTROL register for more details
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*/
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#define EP93XX_DMA_M2P_ABORT_ON_ERROR 0x20 /* Abort on peripheral error */
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#define EP93XX_DMA_M2P_IGNORE_ERROR 0x40 /* Ignore peripheral errors */
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#define EP93XX_DMA_M2P_ERROR_MASK 0x60 /* Mask of error bits */
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/**
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* ep93xx_dma_m2p_client_register - Register a client with the DMA M2P
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* subsystem
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*
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* @m2p: Client information to register
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* returns 0 on success
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*
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* The DMA M2P subsystem allocates a channel and an interrupt line for the DMA
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* client
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*/
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int ep93xx_dma_m2p_client_register(struct ep93xx_dma_m2p_client *m2p);
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/**
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* ep93xx_dma_m2p_client_unregister - Unregister a client from the DMA M2P
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* subsystem
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*
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* @m2p: Client to unregister
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*
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* Any transfers currently in progress will be completed in hardware, but
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* ignored in software.
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*/
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void ep93xx_dma_m2p_client_unregister(struct ep93xx_dma_m2p_client *m2p);
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/**
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* ep93xx_dma_m2p_submit - Submit a DMA M2P transfer
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*
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* @m2p: DMA Client to submit the transfer on
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* @buf: DMA Buffer to submit
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*
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* If the current or next transfer positions are free on the M2P client then
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* the transfer is started immediately. If not, the transfer is added to the
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* list of pending transfers. This function must not be called from the
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* buffer_finished callback for an M2P channel.
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*
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*/
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void ep93xx_dma_m2p_submit(struct ep93xx_dma_m2p_client *m2p,
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struct ep93xx_dma_buffer *buf);
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/**
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* ep93xx_dma_m2p_submit_recursive - Put a DMA transfer on the pending list
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* for an M2P channel
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*
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* @m2p: DMA Client to submit the transfer on
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* @buf: DMA Buffer to submit
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*
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* This function must only be called from the buffer_finished callback for an
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* M2P channel. It is commonly used to add the next transfer in a chained list
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* of DMA transfers.
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*/
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void ep93xx_dma_m2p_submit_recursive(struct ep93xx_dma_m2p_client *m2p,
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struct ep93xx_dma_buffer *buf);
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/**
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* ep93xx_dma_m2p_flush - Flush all pending transfers on a DMA M2P client
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*
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* @m2p: DMA client to flush transfers on
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*
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* Any transfers currently in progress will be completed in hardware, but
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* ignored in software.
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*
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*/
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void ep93xx_dma_m2p_flush(struct ep93xx_dma_m2p_client *m2p);
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#endif /* __ASM_ARCH_DMA_H */
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