diff options
Diffstat (limited to 'drivers/spi/spi-s3c24xx-fiq.S')
| -rw-r--r-- | drivers/spi/spi-s3c24xx-fiq.S | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/drivers/spi/spi-s3c24xx-fiq.S b/drivers/spi/spi-s3c24xx-fiq.S new file mode 100644 index 000000000..1565c792d --- /dev/null +++ b/drivers/spi/spi-s3c24xx-fiq.S @@ -0,0 +1,113 @@ +/* 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) + .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 + subsne 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) + .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 + subsne 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) + .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 + subsne 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 |