-/*
- * arch/arm/mach-ep93xx/include/mach/dma.h
+/**
+ * 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
#include <linux/list.h>
#include <linux/types.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;
struct ep93xx_dma_buffer *buf,
int bytes, int error);
- /* Internal to the DMA code. */
+ /* 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_UART3 0x08
#define EP93XX_DMA_M2P_PORT_IRDA 0x09
#define EP93XX_DMA_M2P_PORT_MASK 0x0f
-#define EP93XX_DMA_M2P_TX 0x00
-#define EP93XX_DMA_M2P_RX 0x10
-#define EP93XX_DMA_M2P_ABORT_ON_ERROR 0x20
-#define EP93XX_DMA_M2P_IGNORE_ERROR 0x40
-#define EP93XX_DMA_M2P_ERROR_MASK 0x60
-int ep93xx_dma_m2p_client_register(struct ep93xx_dma_m2p_client *m2p);
+/* 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);
#endif /* __ASM_ARCH_DMA_H */
git.openpandora.org / pandora-kernel.git / blobdiff