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1 | /* linux/drivers/spi/spi_s3c24xx_fiq.S |
2 | * | |
3 | * Copyright 2009 Simtec Electronics | |
4 | * Ben Dooks <ben@simtec.co.uk> | |
5 | * | |
6 | * S3C24XX SPI - FIQ pseudo-DMA transfer code | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License version 2 as | |
10 | * published by the Free Software Foundation. | |
11 | */ | |
12 | ||
13 | #include <linux/linkage.h> | |
14 | #include <asm/assembler.h> | |
15 | ||
16 | #include <mach/map.h> | |
17 | #include <mach/regs-irq.h> | |
18 | #include <plat/regs-spi.h> | |
19 | ||
ca632f55 | 20 | #include "spi-s3c24xx-fiq.h" |
bec0806c BD |
21 | |
22 | .text | |
23 | ||
24 | @ entry to these routines is as follows, with the register names | |
25 | @ defined in fiq.h so that they can be shared with the C files which | |
26 | @ setup the calling registers. | |
27 | @ | |
28 | @ fiq_rirq The base of the IRQ registers to find S3C2410_SRCPND | |
29 | @ fiq_rtmp Temporary register to hold tx/rx data | |
30 | @ fiq_rspi The base of the SPI register block | |
31 | @ fiq_rtx The tx buffer pointer | |
32 | @ fiq_rrx The rx buffer pointer | |
33 | @ fiq_rcount The number of bytes to move | |
34 | ||
35 | @ each entry starts with a word entry of how long it is | |
36 | @ and an offset to the irq acknowledgment word | |
37 | ||
38 | ENTRY(s3c24xx_spi_fiq_rx) | |
39 | s3c24xx_spi_fix_rx: | |
40 | .word fiq_rx_end - fiq_rx_start | |
41 | .word fiq_rx_irq_ack - fiq_rx_start | |
42 | fiq_rx_start: | |
43 | ldr fiq_rtmp, fiq_rx_irq_ack | |
44 | str fiq_rtmp, [ fiq_rirq, # S3C2410_SRCPND - S3C24XX_VA_IRQ ] | |
45 | ||
46 | ldrb fiq_rtmp, [ fiq_rspi, # S3C2410_SPRDAT ] | |
47 | strb fiq_rtmp, [ fiq_rrx ], #1 | |
48 | ||
49 | mov fiq_rtmp, #0xff | |
50 | strb fiq_rtmp, [ fiq_rspi, # S3C2410_SPTDAT ] | |
51 | ||
52 | subs fiq_rcount, fiq_rcount, #1 | |
53 | subnes pc, lr, #4 @@ return, still have work to do | |
54 | ||
55 | @@ set IRQ controller so that next op will trigger IRQ | |
56 | mov fiq_rtmp, #0 | |
57 | str fiq_rtmp, [ fiq_rirq, # S3C2410_INTMOD - S3C24XX_VA_IRQ ] | |
58 | subs pc, lr, #4 | |
59 | ||
60 | fiq_rx_irq_ack: | |
61 | .word 0 | |
62 | fiq_rx_end: | |
63 | ||
64 | ENTRY(s3c24xx_spi_fiq_txrx) | |
65 | s3c24xx_spi_fiq_txrx: | |
66 | .word fiq_txrx_end - fiq_txrx_start | |
67 | .word fiq_txrx_irq_ack - fiq_txrx_start | |
68 | fiq_txrx_start: | |
69 | ||
70 | ldrb fiq_rtmp, [ fiq_rspi, # S3C2410_SPRDAT ] | |
71 | strb fiq_rtmp, [ fiq_rrx ], #1 | |
72 | ||
73 | ldr fiq_rtmp, fiq_txrx_irq_ack | |
74 | str fiq_rtmp, [ fiq_rirq, # S3C2410_SRCPND - S3C24XX_VA_IRQ ] | |
75 | ||
76 | ldrb fiq_rtmp, [ fiq_rtx ], #1 | |
77 | strb fiq_rtmp, [ fiq_rspi, # S3C2410_SPTDAT ] | |
78 | ||
79 | subs fiq_rcount, fiq_rcount, #1 | |
80 | subnes pc, lr, #4 @@ return, still have work to do | |
81 | ||
82 | mov fiq_rtmp, #0 | |
83 | str fiq_rtmp, [ fiq_rirq, # S3C2410_INTMOD - S3C24XX_VA_IRQ ] | |
84 | subs pc, lr, #4 | |
85 | ||
86 | fiq_txrx_irq_ack: | |
87 | .word 0 | |
88 | ||
89 | fiq_txrx_end: | |
90 | ||
91 | ENTRY(s3c24xx_spi_fiq_tx) | |
92 | s3c24xx_spi_fix_tx: | |
93 | .word fiq_tx_end - fiq_tx_start | |
94 | .word fiq_tx_irq_ack - fiq_tx_start | |
95 | fiq_tx_start: | |
96 | ldrb fiq_rtmp, [ fiq_rspi, # S3C2410_SPRDAT ] | |
97 | ||
98 | ldr fiq_rtmp, fiq_tx_irq_ack | |
99 | str fiq_rtmp, [ fiq_rirq, # S3C2410_SRCPND - S3C24XX_VA_IRQ ] | |
100 | ||
101 | ldrb fiq_rtmp, [ fiq_rtx ], #1 | |
102 | strb fiq_rtmp, [ fiq_rspi, # S3C2410_SPTDAT ] | |
103 | ||
104 | subs fiq_rcount, fiq_rcount, #1 | |
105 | subnes pc, lr, #4 @@ return, still have work to do | |
106 | ||
107 | mov fiq_rtmp, #0 | |
108 | str fiq_rtmp, [ fiq_rirq, # S3C2410_INTMOD - S3C24XX_VA_IRQ ] | |
109 | subs pc, lr, #4 | |
110 | ||
111 | fiq_tx_irq_ack: | |
112 | .word 0 | |
113 | ||
114 | fiq_tx_end: | |
115 | ||
116 | .end |