Gitiles
Code Review Sign In
review.shift-gmbh.com / SHIFTPHONES / mainline / linux / 5a9ffb954a3933d7867f4341684a23e008d6839b / . / drivers / spi / spi-s3c24xx-fiq.S
blob: e95d6282109e7c42ad7675e07fff2d2920ec03f9 [file] [log] [blame]
Thomas Gleixnerd2912cb2019-06-04 10:11:33 +0200[diff] [blame]1/* SPDX-License-Identifier: GPL-2.0-only */
Ben Dooksbec08062009-12-14 22:20:24 -0800[diff] [blame]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
Ben Dooksbec08062009-12-14 22:20:24 -0800[diff] [blame]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
Grant Likelyca632f52011-06-06 01:16:30 -0600[diff] [blame]17#include "spi-s3c24xx-fiq.h"
Ben Dooksbec08062009-12-14 22:20:24 -0800[diff] [blame]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
35ENTRY(s3c24xx_spi_fiq_rx)
36s3c24xx_spi_fix_rx:
37 .word fiq_rx_end - fiq_rx_start
38 .word fiq_rx_irq_ack - fiq_rx_start
39fiq_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
57fiq_rx_irq_ack:
58 .word 0
59fiq_rx_end:
60
61ENTRY(s3c24xx_spi_fiq_txrx)
62s3c24xx_spi_fiq_txrx:
63 .word fiq_txrx_end - fiq_txrx_start
64 .word fiq_txrx_irq_ack - fiq_txrx_start
65fiq_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
83fiq_txrx_irq_ack:
84 .word 0
85
86fiq_txrx_end:
87
88ENTRY(s3c24xx_spi_fiq_tx)
89s3c24xx_spi_fix_tx:
90 .word fiq_tx_end - fiq_tx_start
91 .word fiq_tx_irq_ack - fiq_tx_start
92fiq_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
108fiq_tx_irq_ack:
109 .word 0
110
111fiq_tx_end:
112
113 .end