/* linux/drivers/spi/spi_s3c24xx_fiq.S
*
* Copyright 2009 Simtec Electronics
* Ben Dooks <ben@simtec.co.uk>
*
* S3C24XX SPI - FIQ pseudo-DMA transfer code
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <mach/map.h>
#include <mach/regs-irq.h>
#include <plat/regs-spi.h>
#include "spi_s3c24xx_fiq.h"
.text
@ entry to these routines is as follows, with the register names
@ defined in fiq.h so that they can be shared with the C files which
@ setup the calling registers.
@
@ fiq_rirq The base of the IRQ registers to find S3C2410_SRCPND
@ fiq_rtmp Temporary register to hold tx/rx data
@ fiq_rspi The base of the SPI register block
@ fiq_rtx The tx buffer pointer
@ fiq_rrx The rx buffer pointer
@ fiq_rcount The number of bytes to move
@ each entry starts with a word entry of how long it is
@ and an offset to the irq acknowledgment word
ENTRY(s3c24xx_spi_fiq_rx)
s3c24xx_spi_fix_rx:
.word fiq_rx_end - fiq_rx_start
.word fiq_rx_irq_ack - fiq_rx_start
fiq_rx_start:
ldr fiq_rtmp, fiq_rx_irq_ack
str fiq_rtmp, [ fiq_rirq, # S3C2410_SRCPND - S3C24XX_VA_IRQ ]
ldrb fiq_rtmp, [ fiq_rspi, # S3C2410_SPRDAT ]
strb fiq_rtmp, [ fiq_rrx ], #1
mov fiq_rtmp, #0xff
strb fiq_rtmp, [ fiq_rspi, # S3C2410_SPTDAT ]
subs fiq_rcount, fiq_rcount, #1
subnes pc, lr, #4 @@ return, still have work to do
@@ set IRQ controller so that next op will trigger IRQ
mov fiq_rtmp, #0
str fiq_rtmp, [ fiq_rirq, # S3C2410_INTMOD - S3C24XX_VA_IRQ ]
subs pc, lr, #4
fiq_rx_irq_ack:
.word 0
fiq_rx_end:
ENTRY(s3c24xx_spi_fiq_txrx)
s3c24xx_spi_fiq_txrx:
.word fiq_txrx_end - fiq_txrx_start
.word fiq_txrx_irq_ack - fiq_txrx_start
fiq_txrx_start:
ldrb fiq_rtmp, [ fiq_rspi, # S3C2410_SPRDAT ]
strb fiq_rtmp, [ fiq_rrx ], #1
ldr fiq_rtmp, fiq_txrx_irq_ack
str fiq_rtmp, [ fiq_rirq, # S3C2410_SRCPND - S3C24XX_VA_IRQ ]
ldrb fiq_rtmp, [ fiq_rtx ], #1
strb fiq_rtmp, [ fiq_rspi, # S3C2410_SPTDAT ]
subs fiq_rcount, fiq_rcount, #1
subnes pc, lr, #4 @@ return, still have work to do
mov fiq_rtmp, #0
str fiq_rtmp, [ fiq_rirq, # S3C2410_INTMOD - S3C24XX_VA_IRQ ]
subs pc, lr, #4
fiq_txrx_irq_ack:
.word 0
fiq_txrx_end:
ENTRY(s3c24xx_spi_fiq_tx)
s3c24xx_spi_fix_tx:
.word fiq_tx_end - fiq_tx_start
.word fiq_tx_irq_ack - fiq_tx_start
fiq_tx_start:
ldrb fiq_rtmp, [ fiq_rspi, # S3C2410_SPRDAT ]
ldr fiq_rtmp, fiq_tx_irq_ack
str fiq_rtmp, [ fiq_rirq, # S3C2410_SRCPND - S3C24XX_VA_IRQ ]
ldrb fiq_rtmp, [ fiq_rtx ], #1
strb fiq_rtmp, [ fiq_rspi, # S3C2410_SPTDAT ]
subs fiq_rcount, fiq_rcount, #1
subnes pc, lr, #4 @@ return, still have work to do
mov fiq_rtmp, #0
str fiq_rtmp, [ fiq_rirq, # S3C2410_INTMOD - S3C24XX_VA_IRQ ]
subs pc, lr, #4
fiq_tx_irq_ack:
.word 0
fiq_tx_end:
.end
