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linux-next/drivers/spi/spi-s3c24xx-fiq.S

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spi_s3c24xx: add FIQ pseudo-DMA support Add pseudo-DMA by FIQ to the S3C24XX SPI driver. This allows the driver to get DMA-like performance where there are either no free DMA channels or when doing transfers that required both TX and RX data paths. Since this patch requires the addition of an assembly file to hold the FIQ code, we rename the module (instead of adding a rename of the .c file to this patch). We expect most users are loading this via udev and thus there should be no change to the userland configuration. Signed-off-by: Ben Dooks <ben@simtec.co.uk> Signed-off-by: Simtec Linux Team <linux@simtec.co.uk> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2009-12-15 14:20:24 +08:00
/* 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>
spi: reorganize drivers Sort the SPI makefile and enforce the naming convention spi_*.c for spi drivers. This change also rolls the contents of atmel_spi.h into the .c file since there is only one user of that particular include file. v2: - Use 'spi-' prefix instead of 'spi_' to match what seems to be be the predominant pattern for subsystem prefixes. - Clean up filenames in Kconfig and header comment blocks Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Wolfram Sang <w.sang@pengutronix.de> Acked-by: Linus Walleij <linus.walleij@linaro.org>
2011-06-06 15:16:30 +08:00
#include "spi-s3c24xx-fiq.h"
spi_s3c24xx: add FIQ pseudo-DMA support Add pseudo-DMA by FIQ to the S3C24XX SPI driver. This allows the driver to get DMA-like performance where there are either no free DMA channels or when doing transfers that required both TX and RX data paths. Since this patch requires the addition of an assembly file to hold the FIQ code, we rename the module (instead of adding a rename of the .c file to this patch). We expect most users are loading this via udev and thus there should be no change to the userland configuration. Signed-off-by: Ben Dooks <ben@simtec.co.uk> Signed-off-by: Simtec Linux Team <linux@simtec.co.uk> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2009-12-15 14:20:24 +08:00
.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
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