| /* $Id: dma.h,v 1.7 1992/12/14 00:29:34 root Exp root $ |
| * linux/include/asm/dma.h: Defines for using and allocating dma channels. |
| * Written by Hennus Bergman, 1992. |
| * High DMA channel support & info by Hannu Savolainen |
| * and John Boyd, Nov. 1992. |
| */ |
| |
| #ifndef _ASM_APOLLO_DMA_H |
| #define _ASM_APOLLO_DMA_H |
| |
| #include <asm/apollohw.h> /* need byte IO */ |
| #include <linux/spinlock.h> /* And spinlocks */ |
| #include <linux/delay.h> |
| |
| |
| #define dma_outb(val,addr) (*((volatile unsigned char *)(addr+IO_BASE)) = (val)) |
| #define dma_inb(addr) (*((volatile unsigned char *)(addr+IO_BASE))) |
| |
| /* |
| * NOTES about DMA transfers: |
| * |
| * controller 1: channels 0-3, byte operations, ports 00-1F |
| * controller 2: channels 4-7, word operations, ports C0-DF |
| * |
| * - ALL registers are 8 bits only, regardless of transfer size |
| * - channel 4 is not used - cascades 1 into 2. |
| * - channels 0-3 are byte - addresses/counts are for physical bytes |
| * - channels 5-7 are word - addresses/counts are for physical words |
| * - transfers must not cross physical 64K (0-3) or 128K (5-7) boundaries |
| * - transfer count loaded to registers is 1 less than actual count |
| * - controller 2 offsets are all even (2x offsets for controller 1) |
| * - page registers for 5-7 don't use data bit 0, represent 128K pages |
| * - page registers for 0-3 use bit 0, represent 64K pages |
| * |
| * DMA transfers are limited to the lower 16MB of _physical_ memory. |
| * Note that addresses loaded into registers must be _physical_ addresses, |
| * not logical addresses (which may differ if paging is active). |
| * |
| * Address mapping for channels 0-3: |
| * |
| * A23 ... A16 A15 ... A8 A7 ... A0 (Physical addresses) |
| * | ... | | ... | | ... | |
| * | ... | | ... | | ... | |
| * | ... | | ... | | ... | |
| * P7 ... P0 A7 ... A0 A7 ... A0 |
| * | Page | Addr MSB | Addr LSB | (DMA registers) |
| * |
| * Address mapping for channels 5-7: |
| * |
| * A23 ... A17 A16 A15 ... A9 A8 A7 ... A1 A0 (Physical addresses) |
| * | ... | \ \ ... \ \ \ ... \ \ |
| * | ... | \ \ ... \ \ \ ... \ (not used) |
| * | ... | \ \ ... \ \ \ ... \ |
| * P7 ... P1 (0) A7 A6 ... A0 A7 A6 ... A0 |
| * | Page | Addr MSB | Addr LSB | (DMA registers) |
| * |
| * Again, channels 5-7 transfer _physical_ words (16 bits), so addresses |
| * and counts _must_ be word-aligned (the lowest address bit is _ignored_ at |
| * the hardware level, so odd-byte transfers aren't possible). |
| * |
| * Transfer count (_not # bytes_) is limited to 64K, represented as actual |
| * count - 1 : 64K => 0xFFFF, 1 => 0x0000. Thus, count is always 1 or more, |
| * and up to 128K bytes may be transferred on channels 5-7 in one operation. |
| * |
| */ |
| |
| #define MAX_DMA_CHANNELS 8 |
| |
| /* The maximum address that we can perform a DMA transfer to on this platform */#define MAX_DMA_ADDRESS (PAGE_OFFSET+0x1000000) |
| |
| /* 8237 DMA controllers */ |
| #define IO_DMA1_BASE 0x10C00 /* 8 bit slave DMA, channels 0..3 */ |
| #define IO_DMA2_BASE 0x10D00 /* 16 bit master DMA, ch 4(=slave input)..7 */ |
| |
| /* DMA controller registers */ |
| #define DMA1_CMD_REG (IO_DMA1_BASE+0x08) /* command register (w) */ |
| #define DMA1_STAT_REG (IO_DMA1_BASE+0x08) /* status register (r) */ |
| #define DMA1_REQ_REG (IO_DMA1_BASE+0x09) /* request register (w) */ |
| #define DMA1_MASK_REG (IO_DMA1_BASE+0x0A) /* single-channel mask (w) */ |
| #define DMA1_MODE_REG (IO_DMA1_BASE+0x0B) /* mode register (w) */ |
| #define DMA1_CLEAR_FF_REG (IO_DMA1_BASE+0x0C) /* clear pointer flip-flop (w) */ |
| #define DMA1_TEMP_REG (IO_DMA1_BASE+0x0D) /* Temporary Register (r) */ |
| #define DMA1_RESET_REG (IO_DMA1_BASE+0x0D) /* Master Clear (w) */ |
| #define DMA1_CLR_MASK_REG (IO_DMA1_BASE+0x0E) /* Clear Mask */ |
| #define DMA1_MASK_ALL_REG (IO_DMA1_BASE+0x0F) /* all-channels mask (w) */ |
| |
| #define DMA2_CMD_REG (IO_DMA2_BASE+0x10) /* command register (w) */ |
| #define DMA2_STAT_REG (IO_DMA2_BASE+0x10) /* status register (r) */ |
| #define DMA2_REQ_REG (IO_DMA2_BASE+0x12) /* request register (w) */ |
| #define DMA2_MASK_REG (IO_DMA2_BASE+0x14) /* single-channel mask (w) */ |
| #define DMA2_MODE_REG (IO_DMA2_BASE+0x16) /* mode register (w) */ |
| #define DMA2_CLEAR_FF_REG (IO_DMA2_BASE+0x18) /* clear pointer flip-flop (w) */ |
| #define DMA2_TEMP_REG (IO_DMA2_BASE+0x1A) /* Temporary Register (r) */ |
| #define DMA2_RESET_REG (IO_DMA2_BASE+0x1A) /* Master Clear (w) */ |
| #define DMA2_CLR_MASK_REG (IO_DMA2_BASE+0x1C) /* Clear Mask */ |
| #define DMA2_MASK_ALL_REG (IO_DMA2_BASE+0x1E) /* all-channels mask (w) */ |
| |
| #define DMA_ADDR_0 (IO_DMA1_BASE+0x00) /* DMA address registers */ |
| #define DMA_ADDR_1 (IO_DMA1_BASE+0x02) |
| #define DMA_ADDR_2 (IO_DMA1_BASE+0x04) |
| #define DMA_ADDR_3 (IO_DMA1_BASE+0x06) |
| #define DMA_ADDR_4 (IO_DMA2_BASE+0x00) |
| #define DMA_ADDR_5 (IO_DMA2_BASE+0x04) |
| #define DMA_ADDR_6 (IO_DMA2_BASE+0x08) |
| #define DMA_ADDR_7 (IO_DMA2_BASE+0x0C) |
| |
| #define DMA_CNT_0 (IO_DMA1_BASE+0x01) /* DMA count registers */ |
| #define DMA_CNT_1 (IO_DMA1_BASE+0x03) |
| #define DMA_CNT_2 (IO_DMA1_BASE+0x05) |
| #define DMA_CNT_3 (IO_DMA1_BASE+0x07) |
| #define DMA_CNT_4 (IO_DMA2_BASE+0x02) |
| #define DMA_CNT_5 (IO_DMA2_BASE+0x06) |
| #define DMA_CNT_6 (IO_DMA2_BASE+0x0A) |
| #define DMA_CNT_7 (IO_DMA2_BASE+0x0E) |
| |
| #define DMA_MODE_READ 0x44 /* I/O to memory, no autoinit, increment, single mode */ |
| #define DMA_MODE_WRITE 0x48 /* memory to I/O, no autoinit, increment, single mode */ |
| #define DMA_MODE_CASCADE 0xC0 /* pass thru DREQ->HRQ, DACK<-HLDA only */ |
| |
| #define DMA_AUTOINIT 0x10 |
| |
| #define DMA_8BIT 0 |
| #define DMA_16BIT 1 |
| #define DMA_BUSMASTER 2 |
| |
| 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); |
| } |
| |
| /* enable/disable a specific DMA channel */ |
| static __inline__ void enable_dma(unsigned int dmanr) |
| { |
| if (dmanr<=3) |
| dma_outb(dmanr, DMA1_MASK_REG); |
| else |
| dma_outb(dmanr & 3, DMA2_MASK_REG); |
| } |
| |
| static __inline__ void disable_dma(unsigned int dmanr) |
| { |
| if (dmanr<=3) |
| dma_outb(dmanr | 4, DMA1_MASK_REG); |
| else |
| dma_outb((dmanr & 3) | 4, DMA2_MASK_REG); |
| } |
| |
| /* Clear the 'DMA Pointer Flip Flop'. |
| * Write 0 for LSB/MSB, 1 for MSB/LSB access. |
| * Use this once to initialize the FF to a known state. |
| * After that, keep track of it. :-) |
| * --- In order to do that, the DMA routines below should --- |
| * --- only be used while holding the DMA lock ! --- |
| */ |
| static __inline__ void clear_dma_ff(unsigned int dmanr) |
| { |
| if (dmanr<=3) |
| dma_outb(0, DMA1_CLEAR_FF_REG); |
| else |
| dma_outb(0, DMA2_CLEAR_FF_REG); |
| } |
| |
| /* set mode (above) for a specific DMA channel */ |
| static __inline__ void set_dma_mode(unsigned int dmanr, char mode) |
| { |
| if (dmanr<=3) |
| dma_outb(mode | dmanr, DMA1_MODE_REG); |
| else |
| dma_outb(mode | (dmanr&3), DMA2_MODE_REG); |
| } |
| |
| /* Set transfer address & page bits for specific DMA channel. |
| * Assumes dma flipflop is clear. |
| */ |
| static __inline__ void set_dma_addr(unsigned int dmanr, unsigned int a) |
| { |
| if (dmanr <= 3) { |
| dma_outb( a & 0xff, ((dmanr&3)<<1) + IO_DMA1_BASE ); |
| dma_outb( (a>>8) & 0xff, ((dmanr&3)<<1) + IO_DMA1_BASE ); |
| } else { |
| dma_outb( (a>>1) & 0xff, ((dmanr&3)<<2) + IO_DMA2_BASE ); |
| dma_outb( (a>>9) & 0xff, ((dmanr&3)<<2) + IO_DMA2_BASE ); |
| } |
| } |
| |
| |
| /* Set transfer size (max 64k for DMA1..3, 128k for DMA5..7) for |
| * a specific DMA channel. |
| * You must ensure the parameters are valid. |
| * NOTE: from a manual: "the number of transfers is one more |
| * than the initial word count"! This is taken into account. |
| * Assumes dma flip-flop is clear. |
| * NOTE 2: "count" represents _bytes_ and must be even for channels 5-7. |
| */ |
| static __inline__ void set_dma_count(unsigned int dmanr, unsigned int count) |
| { |
| count--; |
| if (dmanr <= 3) { |
| dma_outb( count & 0xff, ((dmanr&3)<<1) + 1 + IO_DMA1_BASE ); |
| dma_outb( (count>>8) & 0xff, ((dmanr&3)<<1) + 1 + IO_DMA1_BASE ); |
| } else { |
| dma_outb( (count>>1) & 0xff, ((dmanr&3)<<2) + 2 + IO_DMA2_BASE ); |
| dma_outb( (count>>9) & 0xff, ((dmanr&3)<<2) + 2 + IO_DMA2_BASE ); |
| } |
| } |
| |
| |
| /* 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. |
| * |
| * Assumes DMA flip-flop is clear. |
| */ |
| static __inline__ int get_dma_residue(unsigned int dmanr) |
| { |
| unsigned int io_port = (dmanr<=3)? ((dmanr&3)<<1) + 1 + IO_DMA1_BASE |
| : ((dmanr&3)<<2) + 2 + IO_DMA2_BASE; |
| |
| /* using short to get 16-bit wrap around */ |
| unsigned short count; |
| |
| count = 1 + dma_inb(io_port); |
| count += dma_inb(io_port) << 8; |
| |
| return (dmanr<=3)? count : (count<<1); |
| } |
| |
| |
| /* These are in kernel/dma.c: */ |
| extern int request_dma(unsigned int dmanr, const char * device_id); /* reserve a DMA channel */ |
| extern void free_dma(unsigned int dmanr); /* release it again */ |
| |
| /* These are in arch/m68k/apollo/dma.c: */ |
| extern unsigned short dma_map_page(unsigned long phys_addr,int count,int type); |
| extern void dma_unmap_page(unsigned short dma_addr); |
| |
| #endif /* _ASM_APOLLO_DMA_H */ |