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-rw-r--r--drivers/spi/spi-s3c24xx-fiq.S116
1 files changed, 116 insertions, 0 deletions
diff --git a/drivers/spi/spi-s3c24xx-fiq.S b/drivers/spi/spi-s3c24xx-fiq.S
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+++ b/drivers/spi/spi-s3c24xx-fiq.S
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+/* 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
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