diff options
Diffstat (limited to 'arch/arm/include/asm/dma.h')
| -rw-r--r-- | arch/arm/include/asm/dma.h | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/arch/arm/include/asm/dma.h b/arch/arm/include/asm/dma.h new file mode 100644 index 000000000000..75154b193117 --- /dev/null +++ b/arch/arm/include/asm/dma.h @@ -0,0 +1,143 @@ +#ifndef __ASM_ARM_DMA_H +#define __ASM_ARM_DMA_H + +typedef unsigned int dmach_t; + +#include <linux/spinlock.h> +#include <asm/system.h> +#include <asm/scatterlist.h> +#include <mach/dma.h> + +/* + * This is the maximum virtual address which can be DMA'd from. + */ +#ifndef MAX_DMA_ADDRESS +#define MAX_DMA_ADDRESS 0xffffffff +#endif + +/* + * DMA modes + */ +typedef unsigned int dmamode_t; + +#define DMA_MODE_MASK 3 + +#define DMA_MODE_READ 0 +#define DMA_MODE_WRITE 1 +#define DMA_MODE_CASCADE 2 +#define DMA_AUTOINIT 4 + +extern spinlock_t dma_spin_lock; + +static inline unsigned long claim_dma_lock(void) +{ + unsigned long flags; + spin_lock_irqsave(&dma_spin_lock, flags); + return flags; +} + +static inline void release_dma_lock(unsigned long flags) +{ + spin_unlock_irqrestore(&dma_spin_lock, flags); +} + +/* Clear the 'DMA Pointer Flip Flop'. + * Write 0 for LSB/MSB, 1 for MSB/LSB access. + */ +#define clear_dma_ff(channel) + +/* Set only the page register bits of the transfer address. + * + * NOTE: This is an architecture specific function, and should + * be hidden from the drivers + */ +extern void set_dma_page(dmach_t channel, char pagenr); + +/* Request a DMA channel + * + * Some architectures may need to do allocate an interrupt + */ +extern int request_dma(dmach_t channel, const char * device_id); + +/* Free a DMA channel + * + * Some architectures may need to do free an interrupt + */ +extern void free_dma(dmach_t channel); + +/* Enable DMA for this channel + * + * On some architectures, this may have other side effects like + * enabling an interrupt and setting the DMA registers. + */ +extern void enable_dma(dmach_t channel); + +/* Disable DMA for this channel + * + * On some architectures, this may have other side effects like + * disabling an interrupt or whatever. + */ +extern void disable_dma(dmach_t channel); + +/* Test whether the specified channel has an active DMA transfer + */ +extern int dma_channel_active(dmach_t channel); + +/* Set the DMA scatter gather list for this channel + * + * This should not be called if a DMA channel is enabled, + * especially since some DMA architectures don't update the + * DMA address immediately, but defer it to the enable_dma(). + */ +extern void set_dma_sg(dmach_t channel, struct scatterlist *sg, int nr_sg); + +/* Set the DMA address for this channel + * + * This should not be called if a DMA channel is enabled, + * especially since some DMA architectures don't update the + * DMA address immediately, but defer it to the enable_dma(). + */ +extern void __set_dma_addr(dmach_t channel, void *addr); +#define set_dma_addr(channel, addr) \ + __set_dma_addr(channel, bus_to_virt(addr)) + +/* Set the DMA byte count for this channel + * + * This should not be called if a DMA channel is enabled, + * especially since some DMA architectures don't update the + * DMA count immediately, but defer it to the enable_dma(). + */ +extern void set_dma_count(dmach_t channel, unsigned long count); + +/* Set the transfer direction for this channel + * + * This should not be called if a DMA channel is enabled, + * especially since some DMA architectures don't update the + * DMA transfer direction immediately, but defer it to the + * enable_dma(). + */ +extern void set_dma_mode(dmach_t channel, dmamode_t mode); + +/* Set the transfer speed for this channel + */ +extern void set_dma_speed(dmach_t channel, int cycle_ns); + +/* Get DMA residue count. After a DMA transfer, this + * should return zero. Reading this while a DMA transfer is + * still in progress will return unpredictable results. + * If called before the channel has been used, it may return 1. + * Otherwise, it returns the number of _bytes_ left to transfer. + */ +extern int get_dma_residue(dmach_t channel); + +#ifndef NO_DMA +#define NO_DMA 255 +#endif + +#ifdef CONFIG_PCI +extern int isa_dma_bridge_buggy; +#else +#define isa_dma_bridge_buggy (0) +#endif + +#endif /* _ARM_DMA_H */ |