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d2912cb1 | 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
bec0806c BD |
2 | /* linux/drivers/spi/spi_s3c24xx_fiq.S |
3 | * | |
4 | * Copyright 2009 Simtec Electronics | |
5 | * Ben Dooks <ben@simtec.co.uk> | |
6 | * | |
7 | * S3C24XX SPI - FIQ pseudo-DMA transfer code | |
bec0806c BD |
8 | */ |
9 | ||
10 | #include <linux/linkage.h> | |
11 | #include <asm/assembler.h> | |
12 | ||
13 | #include <mach/map.h> | |
14 | #include <mach/regs-irq.h> | |
15 | #include <plat/regs-spi.h> | |
16 | ||
ca632f55 | 17 | #include "spi-s3c24xx-fiq.h" |
bec0806c BD |
18 | |
19 | .text | |
20 | ||
21 | @ entry to these routines is as follows, with the register names | |
22 | @ defined in fiq.h so that they can be shared with the C files which | |
23 | @ setup the calling registers. | |
24 | @ | |
25 | @ fiq_rirq The base of the IRQ registers to find S3C2410_SRCPND | |
26 | @ fiq_rtmp Temporary register to hold tx/rx data | |
27 | @ fiq_rspi The base of the SPI register block | |
28 | @ fiq_rtx The tx buffer pointer | |
29 | @ fiq_rrx The rx buffer pointer | |
30 | @ fiq_rcount The number of bytes to move | |
31 | ||
32 | @ each entry starts with a word entry of how long it is | |
33 | @ and an offset to the irq acknowledgment word | |
34 | ||
35 | ENTRY(s3c24xx_spi_fiq_rx) | |
36 | s3c24xx_spi_fix_rx: | |
37 | .word fiq_rx_end - fiq_rx_start | |
38 | .word fiq_rx_irq_ack - fiq_rx_start | |
39 | fiq_rx_start: | |
40 | ldr fiq_rtmp, fiq_rx_irq_ack | |
41 | str fiq_rtmp, [ fiq_rirq, # S3C2410_SRCPND - S3C24XX_VA_IRQ ] | |
42 | ||
43 | ldrb fiq_rtmp, [ fiq_rspi, # S3C2410_SPRDAT ] | |
44 | strb fiq_rtmp, [ fiq_rrx ], #1 | |
45 | ||
46 | mov fiq_rtmp, #0xff | |
47 | strb fiq_rtmp, [ fiq_rspi, # S3C2410_SPTDAT ] | |
48 | ||
49 | subs fiq_rcount, fiq_rcount, #1 | |
50 | subnes pc, lr, #4 @@ return, still have work to do | |
51 | ||
52 | @@ set IRQ controller so that next op will trigger IRQ | |
53 | mov fiq_rtmp, #0 | |
54 | str fiq_rtmp, [ fiq_rirq, # S3C2410_INTMOD - S3C24XX_VA_IRQ ] | |
55 | subs pc, lr, #4 | |
56 | ||
57 | fiq_rx_irq_ack: | |
58 | .word 0 | |
59 | fiq_rx_end: | |
60 | ||
61 | ENTRY(s3c24xx_spi_fiq_txrx) | |
62 | s3c24xx_spi_fiq_txrx: | |
63 | .word fiq_txrx_end - fiq_txrx_start | |
64 | .word fiq_txrx_irq_ack - fiq_txrx_start | |
65 | fiq_txrx_start: | |
66 | ||
67 | ldrb fiq_rtmp, [ fiq_rspi, # S3C2410_SPRDAT ] | |
68 | strb fiq_rtmp, [ fiq_rrx ], #1 | |
69 | ||
70 | ldr fiq_rtmp, fiq_txrx_irq_ack | |
71 | str fiq_rtmp, [ fiq_rirq, # S3C2410_SRCPND - S3C24XX_VA_IRQ ] | |
72 | ||
73 | ldrb fiq_rtmp, [ fiq_rtx ], #1 | |
74 | strb fiq_rtmp, [ fiq_rspi, # S3C2410_SPTDAT ] | |
75 | ||
76 | subs fiq_rcount, fiq_rcount, #1 | |
77 | subnes pc, lr, #4 @@ return, still have work to do | |
78 | ||
79 | mov fiq_rtmp, #0 | |
80 | str fiq_rtmp, [ fiq_rirq, # S3C2410_INTMOD - S3C24XX_VA_IRQ ] | |
81 | subs pc, lr, #4 | |
82 | ||
83 | fiq_txrx_irq_ack: | |
84 | .word 0 | |
85 | ||
86 | fiq_txrx_end: | |
87 | ||
88 | ENTRY(s3c24xx_spi_fiq_tx) | |
89 | s3c24xx_spi_fix_tx: | |
90 | .word fiq_tx_end - fiq_tx_start | |
91 | .word fiq_tx_irq_ack - fiq_tx_start | |
92 | fiq_tx_start: | |
93 | ldrb fiq_rtmp, [ fiq_rspi, # S3C2410_SPRDAT ] | |
94 | ||
95 | ldr fiq_rtmp, fiq_tx_irq_ack | |
96 | str fiq_rtmp, [ fiq_rirq, # S3C2410_SRCPND - S3C24XX_VA_IRQ ] | |
97 | ||
98 | ldrb fiq_rtmp, [ fiq_rtx ], #1 | |
99 | strb fiq_rtmp, [ fiq_rspi, # S3C2410_SPTDAT ] | |
100 | ||
101 | subs fiq_rcount, fiq_rcount, #1 | |
102 | subnes pc, lr, #4 @@ return, still have work to do | |
103 | ||
104 | mov fiq_rtmp, #0 | |
105 | str fiq_rtmp, [ fiq_rirq, # S3C2410_INTMOD - S3C24XX_VA_IRQ ] | |
106 | subs pc, lr, #4 | |
107 | ||
108 | fiq_tx_irq_ack: | |
109 | .word 0 | |
110 | ||
111 | fiq_tx_end: | |
112 | ||
113 | .end |