137 lines
2.5 KiB
ArmAsm
137 lines
2.5 KiB
ArmAsm
/*
|
|
* Copyright (C) 2009 Sascha Hauer <s.hauer@pengutronix.de>
|
|
*
|
|
* 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>
|
|
|
|
/*
|
|
* r8 = bit 0-15: tx offset, bit 16-31: tx buffer size
|
|
* r9 = bit 0-15: rx offset, bit 16-31: rx buffer size
|
|
*/
|
|
|
|
#define SSI_STX0 0x00
|
|
#define SSI_SRX0 0x08
|
|
#define SSI_SISR 0x14
|
|
#define SSI_SIER 0x18
|
|
#define SSI_SACNT 0x38
|
|
|
|
#define SSI_SACNT_AC97EN (1 << 0)
|
|
|
|
#define SSI_SIER_TFE0_EN (1 << 0)
|
|
#define SSI_SISR_TFE0 (1 << 0)
|
|
#define SSI_SISR_RFF0 (1 << 2)
|
|
#define SSI_SIER_RFF0_EN (1 << 2)
|
|
|
|
.text
|
|
.global imx_ssi_fiq_start
|
|
.global imx_ssi_fiq_end
|
|
.global imx_ssi_fiq_base
|
|
.global imx_ssi_fiq_rx_buffer
|
|
.global imx_ssi_fiq_tx_buffer
|
|
|
|
imx_ssi_fiq_start:
|
|
ldr r12, imx_ssi_fiq_base
|
|
|
|
/* TX */
|
|
ldr r11, imx_ssi_fiq_tx_buffer
|
|
|
|
/* shall we send? */
|
|
ldr r13, [r12, #SSI_SIER]
|
|
tst r13, #SSI_SIER_TFE0_EN
|
|
beq 1f
|
|
|
|
/* TX FIFO empty? */
|
|
ldr r13, [r12, #SSI_SISR]
|
|
tst r13, #SSI_SISR_TFE0
|
|
beq 1f
|
|
|
|
mov r10, #0x10000
|
|
sub r10, #1
|
|
and r10, r10, r8 /* r10: current buffer offset */
|
|
|
|
add r11, r11, r10
|
|
|
|
ldrh r13, [r11]
|
|
strh r13, [r12, #SSI_STX0]
|
|
|
|
ldrh r13, [r11, #2]
|
|
strh r13, [r12, #SSI_STX0]
|
|
|
|
ldrh r13, [r11, #4]
|
|
strh r13, [r12, #SSI_STX0]
|
|
|
|
ldrh r13, [r11, #6]
|
|
strh r13, [r12, #SSI_STX0]
|
|
|
|
add r10, #8
|
|
lsr r13, r8, #16 /* r13: buffer size */
|
|
cmp r10, r13
|
|
lslgt r8, r13, #16
|
|
addle r8, #8
|
|
1:
|
|
/* RX */
|
|
|
|
/* shall we receive? */
|
|
ldr r13, [r12, #SSI_SIER]
|
|
tst r13, #SSI_SIER_RFF0_EN
|
|
beq 1f
|
|
|
|
/* RX FIFO full? */
|
|
ldr r13, [r12, #SSI_SISR]
|
|
tst r13, #SSI_SISR_RFF0
|
|
beq 1f
|
|
|
|
ldr r11, imx_ssi_fiq_rx_buffer
|
|
|
|
mov r10, #0x10000
|
|
sub r10, #1
|
|
and r10, r10, r9 /* r10: current buffer offset */
|
|
|
|
add r11, r11, r10
|
|
|
|
ldr r13, [r12, #SSI_SACNT]
|
|
tst r13, #SSI_SACNT_AC97EN
|
|
|
|
ldr r13, [r12, #SSI_SRX0]
|
|
strh r13, [r11]
|
|
|
|
ldr r13, [r12, #SSI_SRX0]
|
|
strh r13, [r11, #2]
|
|
|
|
/* dummy read to skip slot 12 */
|
|
ldrne r13, [r12, #SSI_SRX0]
|
|
|
|
ldr r13, [r12, #SSI_SRX0]
|
|
strh r13, [r11, #4]
|
|
|
|
ldr r13, [r12, #SSI_SRX0]
|
|
strh r13, [r11, #6]
|
|
|
|
/* dummy read to skip slot 12 */
|
|
ldrne r13, [r12, #SSI_SRX0]
|
|
|
|
add r10, #8
|
|
lsr r13, r9, #16 /* r13: buffer size */
|
|
cmp r10, r13
|
|
lslgt r9, r13, #16
|
|
addle r9, #8
|
|
|
|
1:
|
|
@ return from FIQ
|
|
subs pc, lr, #4
|
|
|
|
.align
|
|
imx_ssi_fiq_base:
|
|
.word 0x0
|
|
imx_ssi_fiq_rx_buffer:
|
|
.word 0x0
|
|
imx_ssi_fiq_tx_buffer:
|
|
.word 0x0
|
|
imx_ssi_fiq_end:
|
|
|