[deliverable/linux.git] / arch / arm / mach-imx / ssi-fiq.S

/*
 *  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>
#include <asm/export.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 is _intentionally_ not marked as a function symbol
 * using ENDPROC().  imx_ssi_fiq_start and imx_ssi_fiq_end are used to
 * mark the function body so that it can be copied to the FIQ vector in
 * the vectors page.  imx_ssi_fiq_start should only be called as the result
 * of an FIQ: calling it directly will not work.
 */
imx_ssi_fiq_start:
		ldr r12, .L_imx_ssi_fiq_base

		/* TX */
		ldr r13, .L_imx_ssi_fiq_tx_buffer

		/* shall we send? */
		ldr r11, [r12, #SSI_SIER]
		tst r11, #SSI_SIER_TFE0_EN
		beq 1f

		/* TX FIFO empty? */
		ldr r11, [r12, #SSI_SISR]
		tst r11, #SSI_SISR_TFE0
		beq 1f

		mov r10, #0x10000
		sub r10, #1
		and r10, r10, r8	/* r10: current buffer offset */

		add r13, r13, r10

		ldrh r11, [r13]
		strh r11, [r12, #SSI_STX0]

		ldrh r11, [r13, #2]
		strh r11, [r12, #SSI_STX0]

		ldrh r11, [r13, #4]
		strh r11, [r12, #SSI_STX0]

		ldrh r11, [r13, #6]
		strh r11, [r12, #SSI_STX0]

		add r10, #8
		lsr r11, r8, #16	/* r11: buffer size */
		cmp r10, r11
		lslgt r8, r11, #16
		addle r8, #8
1:
		/* RX */

		/* shall we receive? */
		ldr r11, [r12, #SSI_SIER]
		tst r11, #SSI_SIER_RFF0_EN
		beq 1f

		/* RX FIFO full? */
		ldr r11, [r12, #SSI_SISR]
		tst r11, #SSI_SISR_RFF0
		beq 1f

		ldr r13, .L_imx_ssi_fiq_rx_buffer

		mov r10, #0x10000
		sub r10, #1
		and r10, r10, r9	/* r10: current buffer offset */

		add r13, r13, r10

		ldr r11, [r12, #SSI_SACNT]
		tst r11, #SSI_SACNT_AC97EN

		ldr r11, [r12, #SSI_SRX0]
		strh r11, [r13]

		ldr r11, [r12, #SSI_SRX0]
		strh r11, [r13, #2]

		/* dummy read to skip slot 12 */
		ldrne r11, [r12, #SSI_SRX0]

		ldr r11, [r12, #SSI_SRX0]
		strh r11, [r13, #4]

		ldr r11, [r12, #SSI_SRX0]
		strh r11, [r13, #6]

		/* dummy read to skip slot 12 */
		ldrne r11, [r12, #SSI_SRX0]

		add r10, #8
		lsr r11, r9, #16	/* r11: buffer size */
		cmp r10, r11
		lslgt r9, r11, #16
		addle r9, #8

1:
		@ return from FIQ
		subs	pc, lr, #4

		.align
.L_imx_ssi_fiq_base:
imx_ssi_fiq_base:
		.word 0x0
.L_imx_ssi_fiq_rx_buffer:
imx_ssi_fiq_rx_buffer:
		.word 0x0
.L_imx_ssi_fiq_tx_buffer:
imx_ssi_fiq_tx_buffer:
		.word 0x0
.L_imx_ssi_fiq_end:
imx_ssi_fiq_end:
EXPORT_SYMBOL(imx_ssi_fiq_tx_buffer)
EXPORT_SYMBOL(imx_ssi_fiq_rx_buffer)
EXPORT_SYMBOL(imx_ssi_fiq_start)
EXPORT_SYMBOL(imx_ssi_fiq_end)
EXPORT_SYMBOL(imx_ssi_fiq_base)
Commit	Line	Data
8380222e SH	1	/*
	2	* Copyright (C) 2009 Sascha Hauer <s.hauer@pengutronix.de>
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2 as
	6	* published by the Free Software Foundation.
	7	*/
	8
	9	#include <linux/linkage.h>
	10	#include <asm/assembler.h>
4dd1837d	11	#include <asm/export.h>
8380222e SH	12
	13	/*
	14	* r8 = bit 0-15: tx offset, bit 16-31: tx buffer size
	15	* r9 = bit 0-15: rx offset, bit 16-31: rx buffer size
	16	*/
	17
	18	#define SSI_STX0 0x00
	19	#define SSI_SRX0 0x08
	20	#define SSI_SISR 0x14
	21	#define SSI_SIER 0x18
	22	#define SSI_SACNT 0x38
	23
	24	#define SSI_SACNT_AC97EN (1 << 0)
	25
	26	#define SSI_SIER_TFE0_EN (1 << 0)
	27	#define SSI_SISR_TFE0 (1 << 0)
	28	#define SSI_SISR_RFF0 (1 << 2)
	29	#define SSI_SIER_RFF0_EN (1 << 2)
	30
	31	.text
	32	.global imx_ssi_fiq_start
	33	.global imx_ssi_fiq_end
	34	.global imx_ssi_fiq_base
	35	.global imx_ssi_fiq_rx_buffer
	36	.global imx_ssi_fiq_tx_buffer
	37
7095b956 DM	38	/*
	39	* imx_ssi_fiq_start is _intentionally_ not marked as a function symbol
	40	* using ENDPROC(). imx_ssi_fiq_start and imx_ssi_fiq_end are used to
	41	* mark the function body so that it can be copied to the FIQ vector in
	42	* the vectors page. imx_ssi_fiq_start should only be called as the result
	43	* of an FIQ: calling it directly will not work.
	44	*/
8380222e	45	imx_ssi_fiq_start:
7095b956	46	ldr r12, .L_imx_ssi_fiq_base
8380222e SH	47
8380222e SH	48	/* TX */
7095b956	49	ldr r13, .L_imx_ssi_fiq_tx_buffer
8380222e SH	50
8380222e SH	51	/* shall we send? */
7095b956 DM	52	ldr r11, [r12, #SSI_SIER]
7095b956 DM	53	tst r11, #SSI_SIER_TFE0_EN
8380222e SH	54	beq 1f
	55
	56	/* TX FIFO empty? */
7095b956 DM	57	ldr r11, [r12, #SSI_SISR]
7095b956 DM	58	tst r11, #SSI_SISR_TFE0
8380222e SH	59	beq 1f
	60
	61	mov r10, #0x10000
	62	sub r10, #1
	63	and r10, r10, r8 /* r10: current buffer offset */
	64
7095b956	65	add r13, r13, r10
8380222e	66
7095b956 DM	67	ldrh r11, [r13]
7095b956 DM	68	strh r11, [r12, #SSI_STX0]
8380222e	69
7095b956 DM	70	ldrh r11, [r13, #2]
7095b956 DM	71	strh r11, [r12, #SSI_STX0]
8380222e	72
7095b956 DM	73	ldrh r11, [r13, #4]
7095b956 DM	74	strh r11, [r12, #SSI_STX0]
8380222e	75
7095b956 DM	76	ldrh r11, [r13, #6]
7095b956 DM	77	strh r11, [r12, #SSI_STX0]
8380222e SH	78
8380222e SH	79	add r10, #8
7095b956 DM	80	lsr r11, r8, #16 /* r11: buffer size */
	81	cmp r10, r11
	82	lslgt r8, r11, #16
8380222e SH	83	addle r8, #8
	84	1:
	85	/* RX */
	86
	87	/* shall we receive? */
7095b956 DM	88	ldr r11, [r12, #SSI_SIER]
7095b956 DM	89	tst r11, #SSI_SIER_RFF0_EN
8380222e SH	90	beq 1f
	91
	92	/* RX FIFO full? */
7095b956 DM	93	ldr r11, [r12, #SSI_SISR]
7095b956 DM	94	tst r11, #SSI_SISR_RFF0
8380222e SH	95	beq 1f
8380222e SH	96
7095b956	97	ldr r13, .L_imx_ssi_fiq_rx_buffer
8380222e SH	98
	99	mov r10, #0x10000
	100	sub r10, #1
	101	and r10, r10, r9 /* r10: current buffer offset */
	102
7095b956	103	add r13, r13, r10
8380222e	104
7095b956 DM	105	ldr r11, [r12, #SSI_SACNT]
7095b956 DM	106	tst r11, #SSI_SACNT_AC97EN
8380222e	107
7095b956 DM	108	ldr r11, [r12, #SSI_SRX0]
7095b956 DM	109	strh r11, [r13]
8380222e	110
7095b956 DM	111	ldr r11, [r12, #SSI_SRX0]
7095b956 DM	112	strh r11, [r13, #2]
8380222e SH	113
8380222e SH	114	/* dummy read to skip slot 12 */
7095b956	115	ldrne r11, [r12, #SSI_SRX0]
8380222e	116
7095b956 DM	117	ldr r11, [r12, #SSI_SRX0]
7095b956 DM	118	strh r11, [r13, #4]
8380222e	119
7095b956 DM	120	ldr r11, [r12, #SSI_SRX0]
7095b956 DM	121	strh r11, [r13, #6]
8380222e SH	122
8380222e SH	123	/* dummy read to skip slot 12 */
7095b956	124	ldrne r11, [r12, #SSI_SRX0]
8380222e SH	125
8380222e SH	126	add r10, #8
7095b956 DM	127	lsr r11, r9, #16 /* r11: buffer size */
	128	cmp r10, r11
	129	lslgt r9, r11, #16
8380222e SH	130	addle r9, #8
	131
	132	1:
	133	@ return from FIQ
	134	subs pc, lr, #4
0575b4b8 DM	135
0575b4b8 DM	136	.align
7095b956	137	.L_imx_ssi_fiq_base:
8380222e SH	138	imx_ssi_fiq_base:
8380222e SH	139	.word 0x0
7095b956	140	.L_imx_ssi_fiq_rx_buffer:
8380222e SH	141	imx_ssi_fiq_rx_buffer:
8380222e SH	142	.word 0x0
7095b956	143	.L_imx_ssi_fiq_tx_buffer:
8380222e SH	144	imx_ssi_fiq_tx_buffer:
8380222e SH	145	.word 0x0
7095b956	146	.L_imx_ssi_fiq_end:
8380222e	147	imx_ssi_fiq_end:
4dd1837d AV	148	EXPORT_SYMBOL(imx_ssi_fiq_tx_buffer)
	149	EXPORT_SYMBOL(imx_ssi_fiq_rx_buffer)
	150	EXPORT_SYMBOL(imx_ssi_fiq_start)
	151	EXPORT_SYMBOL(imx_ssi_fiq_end)
	152	EXPORT_SYMBOL(imx_ssi_fiq_base)