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gerrit-public.fairphone.software / kernel / msm-4.9 / 3270ac230f660843a7f7d631746ee2c8ee63f347 / . / drivers / spi / spi-s3c24xx-fiq.S
blob: 059f2dc1fda2d63a60ccdac4d5141942b6363b81 [file] [log] [blame]
Ben Dooksbec08062009-12-14 22:20:24 -0800[diff] [blame]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
Grant Likelyca632f52011-06-06 01:16:30 -0600[diff] [blame]20#include "spi-s3c24xx-fiq.h"
Ben Dooksbec08062009-12-14 22:20:24 -0800[diff] [blame]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
38ENTRY(s3c24xx_spi_fiq_rx)
39s3c24xx_spi_fix_rx:
40 .word fiq_rx_end - fiq_rx_start
41 .word fiq_rx_irq_ack - fiq_rx_start
42fiq_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
60fiq_rx_irq_ack:
61 .word 0
62fiq_rx_end:
63
64ENTRY(s3c24xx_spi_fiq_txrx)
65s3c24xx_spi_fiq_txrx:
66 .word fiq_txrx_end - fiq_txrx_start
67 .word fiq_txrx_irq_ack - fiq_txrx_start
68fiq_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
86fiq_txrx_irq_ack:
87 .word 0
88
89fiq_txrx_end:
90
91ENTRY(s3c24xx_spi_fiq_tx)
92s3c24xx_spi_fix_tx:
93 .word fiq_tx_end - fiq_tx_start
94 .word fiq_tx_irq_ack - fiq_tx_start
95fiq_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
111fiq_tx_irq_ack:
112 .word 0
113
114fiq_tx_end:
115
116 .end