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/**
* DOC: EP93xx DMA M2P memory to peripheral and peripheral to memory engine
*
* The EP93xx DMA M2P subsystem handles DMA transfers between memory and
* peripherals. DMA M2P channels are available for audio, UARTs and IrDA.
* See chapter 10 of the EP93xx users guide for full details on the DMA M2P
* engine.
*
* See sound/soc/ep93xx/ep93xx-pcm.c for an example use of the DMA M2P code.
*
*/
#ifndef __ASM_ARCH_DMA_H
#define __ASM_ARCH_DMA_H
#include <linux/list.h>
#include <linux/types.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
/**
* struct ep93xx_dma_buffer - Information about a buffer to be transferred
* using the DMA M2P engine
*
* @list: Entry in DMA buffer list
* @bus_addr: Physical address of the buffer
* @size: Size of the buffer in bytes
*/
struct ep93xx_dma_buffer {
struct list_head list;
u32 bus_addr;
u16 size;
};
/**
* struct ep93xx_dma_m2p_client - Information about a DMA M2P client
*
* @name: Unique name for this client
* @flags: Client flags
* @cookie: User data to pass to callback functions
* @buffer_started: Non NULL function to call when a transfer is started.
* The arguments are the user data cookie and the DMA
* buffer which is starting.
* @buffer_finished: Non NULL function to call when a transfer is completed.
* The arguments are the user data cookie, the DMA buffer
* which has completed, and a boolean flag indicating if
* the transfer had an error.
*/
struct ep93xx_dma_m2p_client {
char *name;
u8 flags;
void *cookie;
void (*buffer_started)(void *cookie,
struct ep93xx_dma_buffer *buf);
void (*buffer_finished)(void *cookie,
struct ep93xx_dma_buffer *buf,
int bytes, int error);
/* private: Internal use only */
void *channel;
};
/* DMA M2P ports */
#define EP93XX_DMA_M2P_PORT_I2S1 0x00
#define EP93XX_DMA_M2P_PORT_I2S2 0x01
#define EP93XX_DMA_M2P_PORT_AAC1 0x02
#define EP93XX_DMA_M2P_PORT_AAC2 0x03
#define EP93XX_DMA_M2P_PORT_AAC3 0x04
#define EP93XX_DMA_M2P_PORT_I2S3 0x05
#define EP93XX_DMA_M2P_PORT_UART1 0x06
#define EP93XX_DMA_M2P_PORT_UART2 0x07
#define EP93XX_DMA_M2P_PORT_UART3 0x08
#define EP93XX_DMA_M2P_PORT_IRDA 0x09
#define EP93XX_DMA_M2P_PORT_MASK 0x0f
/* DMA M2P client flags */
#define EP93XX_DMA_M2P_TX 0x00 /* Memory to peripheral */
#define EP93XX_DMA_M2P_RX 0x10 /* Peripheral to memory */
/*
* DMA M2P client error handling flags. See the EP93xx users guide
* documentation on the DMA M2P CONTROL register for more details
*/
#define EP93XX_DMA_M2P_ABORT_ON_ERROR 0x20 /* Abort on peripheral error */
#define EP93XX_DMA_M2P_IGNORE_ERROR 0x40 /* Ignore peripheral errors */
#define EP93XX_DMA_M2P_ERROR_MASK 0x60 /* Mask of error bits */
/**
* ep93xx_dma_m2p_client_register - Register a client with the DMA M2P
* subsystem
*
* @m2p: Client information to register
* returns 0 on success
*
* The DMA M2P subsystem allocates a channel and an interrupt line for the DMA
* client
*/
int ep93xx_dma_m2p_client_register(struct ep93xx_dma_m2p_client *m2p);
/**
* ep93xx_dma_m2p_client_unregister - Unregister a client from the DMA M2P
* subsystem
*
* @m2p: Client to unregister
*
* Any transfers currently in progress will be completed in hardware, but
* ignored in software.
*/
void ep93xx_dma_m2p_client_unregister(struct ep93xx_dma_m2p_client *m2p);
/**
* ep93xx_dma_m2p_submit - Submit a DMA M2P transfer
*
* @m2p: DMA Client to submit the transfer on
* @buf: DMA Buffer to submit
*
* If the current or next transfer positions are free on the M2P client then
* the transfer is started immediately. If not, the transfer is added to the
* list of pending transfers. This function must not be called from the
* buffer_finished callback for an M2P channel.
*
*/
void ep93xx_dma_m2p_submit(struct ep93xx_dma_m2p_client *m2p,
struct ep93xx_dma_buffer *buf);
/**
* ep93xx_dma_m2p_submit_recursive - Put a DMA transfer on the pending list
* for an M2P channel
*
* @m2p: DMA Client to submit the transfer on
* @buf: DMA Buffer to submit
*
* This function must only be called from the buffer_finished callback for an
* M2P channel. It is commonly used to add the next transfer in a chained list
* of DMA transfers.
*/
void ep93xx_dma_m2p_submit_recursive(struct ep93xx_dma_m2p_client *m2p,
struct ep93xx_dma_buffer *buf);
/**
* ep93xx_dma_m2p_flush - Flush all pending transfers on a DMA M2P client
*
* @m2p: DMA client to flush transfers on
*
* Any transfers currently in progress will be completed in hardware, but
* ignored in software.
*
*/
void ep93xx_dma_m2p_flush(struct ep93xx_dma_m2p_client *m2p);
/*
* M2P channels.
*
* Note that these values are also directly used for setting the PPALLOC
* register.
*/
#define EP93XX_DMA_I2S1 0
#define EP93XX_DMA_I2S2 1
#define EP93XX_DMA_AAC1 2
#define EP93XX_DMA_AAC2 3
#define EP93XX_DMA_AAC3 4
#define EP93XX_DMA_I2S3 5
#define EP93XX_DMA_UART1 6
#define EP93XX_DMA_UART2 7
#define EP93XX_DMA_UART3 8
#define EP93XX_DMA_IRDA 9
/* M2M channels */
#define EP93XX_DMA_SSP 10
#define EP93XX_DMA_IDE 11
/**
* struct ep93xx_dma_data - configuration data for the EP93xx dmaengine
* @port: peripheral which is requesting the channel
* @direction: TX/RX channel
* @name: optional name for the channel, this is displayed in /proc/interrupts
*
* This information is passed as private channel parameter in a filter
* function. Note that this is only needed for slave/cyclic channels. For
* memcpy channels %NULL data should be passed.
*/
struct ep93xx_dma_data {
int port;
enum dma_data_direction direction;
const char *name;
};
/**
* struct ep93xx_dma_chan_data - platform specific data for a DMA channel
* @name: name of the channel, used for getting the right clock for the channel
* @base: mapped registers
* @irq: interrupt number used by this channel
*/
struct ep93xx_dma_chan_data {
const char *name;
void __iomem *base;
int irq;
};
/**
* struct ep93xx_dma_platform_data - platform data for the dmaengine driver
* @channels: array of channels which are passed to the driver
* @num_channels: number of channels in the array
*
* This structure is passed to the DMA engine driver via platform data. For
* M2P channels, contract is that even channels are for TX and odd for RX.
* There is no requirement for the M2M channels.
*/
struct ep93xx_dma_platform_data {
struct ep93xx_dma_chan_data *channels;
size_t num_channels;
};
static inline bool ep93xx_dma_chan_is_m2p(struct dma_chan *chan)
{
return !strcmp(dev_name(chan->device->dev), "ep93xx-dma-m2p");
}
/**
* ep93xx_dma_chan_direction - returns direction the channel can be used
* @chan: channel
*
* This function can be used in filter functions to find out whether the
* channel supports given DMA direction. Only M2P channels have such
* limitation, for M2M channels the direction is configurable.
*/
static inline enum dma_data_direction
ep93xx_dma_chan_direction(struct dma_chan *chan)
{
if (!ep93xx_dma_chan_is_m2p(chan))
return DMA_NONE;
/* even channels are for TX, odd for RX */
return (chan->chan_id % 2 == 0) ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
}
#endif /* __ASM_ARCH_DMA_H */
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