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| -rw-r--r-- | arch/parisc/include/asm/dma.h | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/arch/parisc/include/asm/dma.h b/arch/parisc/include/asm/dma.h new file mode 100644 index 0000000000..582fb5d1a5 --- /dev/null +++ b/arch/parisc/include/asm/dma.h @@ -0,0 +1,181 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* 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. + * (c) Copyright 2000, Grant Grundler + */ + +#ifndef _ASM_DMA_H +#define _ASM_DMA_H + +#include <asm/io.h> /* need byte IO */ + +#define dma_outb outb +#define dma_inb inb + +extern unsigned long pcxl_dma_start; + +/* +** DMA_CHUNK_SIZE is used by the SCSI mid-layer to break up +** (or rather not merge) DMAs into manageable chunks. +** On parisc, this is more of the software/tuning constraint +** rather than the HW. I/O MMU allocation algorithms can be +** faster with smaller sizes (to some degree). +*/ +#define DMA_CHUNK_SIZE (BITS_PER_LONG*PAGE_SIZE) + +/* The maximum address that we can perform a DMA transfer to on this platform +** New dynamic DMA interfaces should obsolete this.... +*/ +#define MAX_DMA_ADDRESS (~0UL) + +/* +** We don't have DMA channels... well V-class does but the +** Dynamic DMA Mapping interface will support them... right? :^) +** Note: this is not relevant right now for PA-RISC, but we cannot +** leave this as undefined because some things (e.g. sound) +** won't compile :-( +*/ +#define MAX_DMA_CHANNELS 8 +#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 + +/* 8237 DMA controllers */ +#define IO_DMA1_BASE 0x00 /* 8 bit slave DMA, channels 0..3 */ +#define IO_DMA2_BASE 0xC0 /* 16 bit master DMA, ch 4(=slave input)..7 */ + +/* DMA controller registers */ +#define DMA1_CMD_REG 0x08 /* command register (w) */ +#define DMA1_STAT_REG 0x08 /* status register (r) */ +#define DMA1_REQ_REG 0x09 /* request register (w) */ +#define DMA1_MASK_REG 0x0A /* single-channel mask (w) */ +#define DMA1_MODE_REG 0x0B /* mode register (w) */ +#define DMA1_CLEAR_FF_REG 0x0C /* clear pointer flip-flop (w) */ +#define DMA1_TEMP_REG 0x0D /* Temporary Register (r) */ +#define DMA1_RESET_REG 0x0D /* Master Clear (w) */ +#define DMA1_CLR_MASK_REG 0x0E /* Clear Mask */ +#define DMA1_MASK_ALL_REG 0x0F /* all-channels mask (w) */ +#define DMA1_EXT_MODE_REG (0x400 | DMA1_MODE_REG) + +#define DMA2_CMD_REG 0xD0 /* command register (w) */ +#define DMA2_STAT_REG 0xD0 /* status register (r) */ +#define DMA2_REQ_REG 0xD2 /* request register (w) */ +#define DMA2_MASK_REG 0xD4 /* single-channel mask (w) */ +#define DMA2_MODE_REG 0xD6 /* mode register (w) */ +#define DMA2_CLEAR_FF_REG 0xD8 /* clear pointer flip-flop (w) */ +#define DMA2_TEMP_REG 0xDA /* Temporary Register (r) */ +#define DMA2_RESET_REG 0xDA /* Master Clear (w) */ +#define DMA2_CLR_MASK_REG 0xDC /* Clear Mask */ +#define DMA2_MASK_ALL_REG 0xDE /* all-channels mask (w) */ +#define DMA2_EXT_MODE_REG (0x400 | DMA2_MODE_REG) + +static __inline__ unsigned long claim_dma_lock(void) +{ + return 0; +} + +static __inline__ void release_dma_lock(unsigned long flags) +{ +} + + +/* 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); +} + +/* enable/disable a specific DMA channel */ +static __inline__ void enable_dma(unsigned int dmanr) +{ +#ifdef CONFIG_SUPERIO + if (dmanr<=3) + dma_outb(dmanr, DMA1_MASK_REG); + else + dma_outb(dmanr & 3, DMA2_MASK_REG); +#endif +} + +static __inline__ void disable_dma(unsigned int dmanr) +{ +#ifdef CONFIG_SUPERIO + if (dmanr<=3) + dma_outb(dmanr | 4, DMA1_MASK_REG); + else + dma_outb((dmanr & 3) | 4, DMA2_MASK_REG); +#endif +} + +/* reserve a DMA channel */ +#define request_dma(dmanr, device_id) (0) + +/* 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) +{ +} + +/* set mode (above) for a specific DMA channel */ +static __inline__ void set_dma_mode(unsigned int dmanr, char mode) +{ +} + +/* Set only the page register bits of the transfer address. + * This is used for successive transfers when we know the contents of + * the lower 16 bits of the DMA current address register, but a 64k boundary + * may have been crossed. + */ +static __inline__ void set_dma_page(unsigned int dmanr, char pagenr) +{ +} + + +/* 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) +{ +} + + +/* 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) +{ +} + + +#define free_dma(dmanr) + +#endif /* _ASM_DMA_H */ |