arch/arm/mach-omap1/ams-delta-fiq-handler.S - linux - Git at Google

 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
  *  linux/arch/arm/mach-omap1/ams-delta-fiq-handler.S
  *
  *  Based on  linux/arch/arm/lib/floppydma.S
  *  Renamed and modified to work with 2.6 kernel by Matt Callow
  *  Copyright (C) 1995, 1996 Russell King
  *  Copyright (C) 2004 Pete Trapps
  *  Copyright (C) 2006 Matt Callow
  *  Copyright (C) 2010 Janusz Krzysztofik
  */

 #include <linux/linkage.h>
 #include <linux/platform_data/ams-delta-fiq.h>
 #include <linux/platform_data/gpio-omap.h>
 #include <linux/soc/ti/omap1-io.h>

 #include <asm/assembler.h>
 #include <asm/irq.h>

 #include "hardware.h"
 #include "ams-delta-fiq.h"
 #include "board-ams-delta.h"
 #include "iomap.h"

 /*
  * OMAP1510 GPIO related symbol copied from arch/arm/mach-omap1/gpio15xx.c.
  * Unfortunately, it was not placed in a separate header file.
  */
 #define OMAP1510_GPIO_BASE		0xFFFCE000

 /* GPIO register bitmasks */
 #define KEYBRD_DATA_MASK		(0x1 << AMS_DELTA_GPIO_PIN_KEYBRD_DATA)
 #define KEYBRD_CLK_MASK			(0x1 << AMS_DELTA_GPIO_PIN_KEYBRD_CLK)
 #define MODEM_IRQ_MASK			(0x1 << AMS_DELTA_GPIO_PIN_MODEM_IRQ)
 #define HOOK_SWITCH_MASK		(0x1 << AMS_DELTA_GPIO_PIN_HOOK_SWITCH)
 #define OTHERS_MASK			(MODEM_IRQ_MASK | HOOK_SWITCH_MASK)

 /* IRQ handler register bitmasks */
 #define DEFERRED_FIQ_MASK		OMAP_IRQ_BIT(INT_DEFERRED_FIQ)
 #define GPIO_BANK1_MASK  		OMAP_IRQ_BIT(INT_GPIO_BANK1)

 /* Driver buffer byte offsets */
 #define BUF_MASK			(FIQ_MASK * 4)
 #define BUF_STATE			(FIQ_STATE * 4)
 #define BUF_KEYS_CNT			(FIQ_KEYS_CNT * 4)
 #define BUF_TAIL_OFFSET			(FIQ_TAIL_OFFSET * 4)
 #define BUF_HEAD_OFFSET			(FIQ_HEAD_OFFSET * 4)
 #define BUF_BUF_LEN			(FIQ_BUF_LEN * 4)
 #define BUF_KEY				(FIQ_KEY * 4)
 #define BUF_MISSED_KEYS			(FIQ_MISSED_KEYS * 4)
 #define BUF_BUFFER_START		(FIQ_BUFFER_START * 4)
 #define BUF_GPIO_INT_MASK		(FIQ_GPIO_INT_MASK * 4)
 #define BUF_KEYS_HICNT			(FIQ_KEYS_HICNT * 4)
 #define BUF_IRQ_PEND			(FIQ_IRQ_PEND * 4)
 #define BUF_SIR_CODE_L1			(FIQ_SIR_CODE_L1 * 4)
 #define BUF_SIR_CODE_L2			(IRQ_SIR_CODE_L2 * 4)
 #define BUF_CNT_INT_00			(FIQ_CNT_INT_00 * 4)
 #define BUF_CNT_INT_KEY			(FIQ_CNT_INT_KEY * 4)
 #define BUF_CNT_INT_MDM			(FIQ_CNT_INT_MDM * 4)
 #define BUF_CNT_INT_03			(FIQ_CNT_INT_03 * 4)
 #define BUF_CNT_INT_HSW			(FIQ_CNT_INT_HSW * 4)
 #define BUF_CNT_INT_05			(FIQ_CNT_INT_05 * 4)
 #define BUF_CNT_INT_06			(FIQ_CNT_INT_06 * 4)
 #define BUF_CNT_INT_07			(FIQ_CNT_INT_07 * 4)
 #define BUF_CNT_INT_08			(FIQ_CNT_INT_08 * 4)
 #define BUF_CNT_INT_09			(FIQ_CNT_INT_09 * 4)
 #define BUF_CNT_INT_10			(FIQ_CNT_INT_10 * 4)
 #define BUF_CNT_INT_11			(FIQ_CNT_INT_11 * 4)
 #define BUF_CNT_INT_12			(FIQ_CNT_INT_12 * 4)
 #define BUF_CNT_INT_13			(FIQ_CNT_INT_13 * 4)
 #define BUF_CNT_INT_14			(FIQ_CNT_INT_14 * 4)
 #define BUF_CNT_INT_15			(FIQ_CNT_INT_15 * 4)
 #define BUF_CIRC_BUFF			(FIQ_CIRC_BUFF * 4)


 /*
  * Register usage
  * r8  - temporary
  * r9  - the driver buffer
  * r10 - temporary
  * r11 - interrupts mask
  * r12 - base pointers
  * r13 - interrupts status
  */

 	.text

 	.global qwerty_fiqin_end

 ENTRY(qwerty_fiqin_start)
 	@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
 	@ FIQ intrrupt handler
 	ldr r12, omap_ih1_base			@ set pointer to level1 handler

 	ldr r11, [r12, #IRQ_MIR_REG_OFFSET]	@ fetch interrupts mask

 	ldr r13, [r12, #IRQ_ITR_REG_OFFSET]	@ fetch interrupts status
 	bics r13, r13, r11			@ clear masked - any left?
 	beq exit				@ none - spurious FIQ? exit

 	ldr r10, [r12, #IRQ_SIR_FIQ_REG_OFFSET]	@ get requested interrupt number

 	mov r8, #2				@ reset FIQ agreement
 	str r8, [r12, #IRQ_CONTROL_REG_OFFSET]

 	cmp r10, #(INT_GPIO_BANK1 - NR_IRQS_LEGACY)	@ is it GPIO interrupt?
 	beq gpio				@ yes - process it

 	mov r8, #1
 	orr r8, r11, r8, lsl r10		@ mask spurious interrupt
 	str r8, [r12, #IRQ_MIR_REG_OFFSET]
 exit:
 	subs	pc, lr, #4			@ return from FIQ
 	@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@


 	@@@@@@@@@@@@@@@@@@@@@@@@@@@
 gpio:	@ GPIO bank interrupt handler
 	ldr r12, omap1510_gpio_base		@ set base pointer to GPIO bank

 	ldr r11, [r12, #OMAP1510_GPIO_INT_MASK]	@ fetch GPIO interrupts mask
 restart:
 	ldr r13, [r12, #OMAP1510_GPIO_INT_STATUS]	@ fetch status bits
 	bics r13, r13, r11			@ clear masked - any left?
 	beq exit				@ no - spurious interrupt? exit

 	orr r11, r11, r13			@ mask all requested interrupts
 	str r11, [r12, #OMAP1510_GPIO_INT_MASK]

 	str r13, [r12, #OMAP1510_GPIO_INT_STATUS] @ ack all requested interrupts

 	ands r10, r13, #KEYBRD_CLK_MASK		@ extract keyboard status - set?
 	beq hksw				@ no - try next source


 	@@@@@@@@@@@@@@@@@@@@@@
 	@ Keyboard clock FIQ mode interrupt handler
 	@ r10 now contains KEYBRD_CLK_MASK, use it
 	bic r11, r11, r10				@ unmask it
 	str r11, [r12, #OMAP1510_GPIO_INT_MASK]

 	@ Process keyboard data
 	ldr r8, [r12, #OMAP1510_GPIO_DATA_INPUT]	@ fetch GPIO input

 	ldr r10, [r9, #BUF_STATE]		@ fetch kbd interface state
 	cmp r10, #0				@ are we expecting start bit?
 	bne data				@ no - go to data processing

 	ands r8, r8, #KEYBRD_DATA_MASK		@ check start bit - detected?
 	beq hksw				@ no - try next source

 	@ r8 contains KEYBRD_DATA_MASK, use it
 	str r8, [r9, #BUF_STATE]		@ enter data processing state
 	@ r10 already contains 0, reuse it
 	str r10, [r9, #BUF_KEY]			@ clear keycode
 	mov r10, #2				@ reset input bit mask
 	str r10, [r9, #BUF_MASK]

 	@ Mask other GPIO line interrupts till key done
 	str r11, [r9, #BUF_GPIO_INT_MASK]	@ save mask for later restore
 	mvn r11, #KEYBRD_CLK_MASK		@ prepare all except kbd mask
 	str r11, [r12, #OMAP1510_GPIO_INT_MASK]	@ store into the mask register

 	b restart				@ restart

 data:	ldr r10, [r9, #BUF_MASK]		@ fetch current input bit mask

 	@ r8 still contains GPIO input bits
 	ands r8, r8, #KEYBRD_DATA_MASK		@ is keyboard data line low?
 	ldreq r8, [r9, #BUF_KEY]		@ yes - fetch collected so far,
 	orreq r8, r8, r10			@ set 1 at current mask position
 	streq r8, [r9, #BUF_KEY]		@ and save back

 	mov r10, r10, lsl #1			@ shift mask left
 	bics r10, r10, #0x800			@ have we got all the bits?
 	strne r10, [r9, #BUF_MASK]		@ not yet - store the mask
 	bne restart				@ and restart

 	@ r10 already contains 0, reuse it
 	str r10, [r9, #BUF_STATE]		@ reset state to start

 	@ Key done - restore interrupt mask
 	ldr r10, [r9, #BUF_GPIO_INT_MASK]	@ fetch saved mask
 	and r11, r11, r10			@ unmask all saved as unmasked
 	str r11, [r12, #OMAP1510_GPIO_INT_MASK]	@ restore into the mask register

 	@ Try appending the keycode to the circular buffer
 	ldr r10, [r9, #BUF_KEYS_CNT]		@ get saved keystrokes count
 	ldr r8, [r9, #BUF_BUF_LEN]		@ get buffer size
 	cmp r10, r8				@ is buffer full?
 	beq hksw				@ yes - key lost, next source

 	add r10, r10, #1			@ incremet keystrokes counter
 	str r10, [r9, #BUF_KEYS_CNT]

 	ldr r10, [r9, #BUF_TAIL_OFFSET]		@ get buffer tail offset
 	@ r8 already contains buffer size
 	cmp r10, r8				@ end of buffer?
 	moveq r10, #0				@ yes - rewind to buffer start

 	ldr r12, [r9, #BUF_BUFFER_START]	@ get buffer start address
 	add r12, r12, r10, LSL #2		@ calculate buffer tail address
 	ldr r8, [r9, #BUF_KEY]			@ get last keycode
 	str r8, [r12]				@ append it to the buffer tail

 	add r10, r10, #1			@ increment buffer tail offset
 	str r10, [r9, #BUF_TAIL_OFFSET]

 	ldr r10, [r9, #BUF_CNT_INT_KEY]		@ increment interrupts counter
 	add r10, r10, #1
 	str r10, [r9, #BUF_CNT_INT_KEY]
 	@@@@@@@@@@@@@@@@@@@@@@@@


 hksw:	@Is hook switch interrupt requested?
 	tst r13, #HOOK_SWITCH_MASK 		@ is hook switch status bit set?
 	beq mdm					@ no - try next source


 	@@@@@@@@@@@@@@@@@@@@@@@@
 	@ Hook switch interrupt FIQ mode simple handler

 	@ Don't toggle active edge, the switch always bounces

 	@ Increment hook switch interrupt counter
 	ldr r10, [r9, #BUF_CNT_INT_HSW]
 	add r10, r10, #1
 	str r10, [r9, #BUF_CNT_INT_HSW]
 	@@@@@@@@@@@@@@@@@@@@@@@@


 mdm:	@Is it a modem interrupt?
 	tst r13, #MODEM_IRQ_MASK 		@ is modem status bit set?
 	beq irq					@ no - check for next interrupt


 	@@@@@@@@@@@@@@@@@@@@@@@@
 	@ Modem FIQ mode interrupt handler stub

 	@ Increment modem interrupt counter
 	ldr r10, [r9, #BUF_CNT_INT_MDM]
 	add r10, r10, #1
 	str r10, [r9, #BUF_CNT_INT_MDM]
 	@@@@@@@@@@@@@@@@@@@@@@@@


 irq:	@ Place deferred_fiq interrupt request
 	ldr r12, deferred_fiq_ih_base		@ set pointer to IRQ handler
 	mov r10, #DEFERRED_FIQ_MASK		@ set deferred_fiq bit
 	str r10, [r12, #IRQ_ISR_REG_OFFSET] 	@ place it in the ISR register

 	ldr r12, omap1510_gpio_base		@ set pointer back to GPIO bank
 	b restart				@ check for next GPIO interrupt
 	@@@@@@@@@@@@@@@@@@@@@@@@@@@


 /*
  * Virtual addresses for IO
  */
 omap_ih1_base:
 	.word OMAP1_IO_ADDRESS(OMAP_IH1_BASE)
 deferred_fiq_ih_base:
 	.word OMAP1_IO_ADDRESS(DEFERRED_FIQ_IH_BASE)
 omap1510_gpio_base:
 	.word OMAP1_IO_ADDRESS(OMAP1510_GPIO_BASE)
 qwerty_fiqin_end:

 /*
  * Check the size of the FIQ,
  * it cannot go beyond 0xffff0200, and is copied to 0xffff001c
  */
 .if (qwerty_fiqin_end - qwerty_fiqin_start) > (0x200 - 0x1c)
 	.err
 .endif
	/* SPDX-License-Identifier: GPL-2.0-only */
	/*
	* linux/arch/arm/mach-omap1/ams-delta-fiq-handler.S
	*
	* Based on linux/arch/arm/lib/floppydma.S
	* Renamed and modified to work with 2.6 kernel by Matt Callow
	* Copyright (C) 1995, 1996 Russell King
	* Copyright (C) 2004 Pete Trapps
	* Copyright (C) 2006 Matt Callow
	* Copyright (C) 2010 Janusz Krzysztofik
	*/

	#include <linux/linkage.h>
	#include <linux/platform_data/ams-delta-fiq.h>
	#include <linux/platform_data/gpio-omap.h>
	#include <linux/soc/ti/omap1-io.h>

	#include <asm/assembler.h>
	#include <asm/irq.h>

	#include "hardware.h"
	#include "ams-delta-fiq.h"
	#include "board-ams-delta.h"
	#include "iomap.h"

	/*
	* OMAP1510 GPIO related symbol copied from arch/arm/mach-omap1/gpio15xx.c.
	* Unfortunately, it was not placed in a separate header file.
	*/
	#define OMAP1510_GPIO_BASE 0xFFFCE000

	/* GPIO register bitmasks */
	#define KEYBRD_DATA_MASK (0x1 << AMS_DELTA_GPIO_PIN_KEYBRD_DATA)
	#define KEYBRD_CLK_MASK (0x1 << AMS_DELTA_GPIO_PIN_KEYBRD_CLK)
	#define MODEM_IRQ_MASK (0x1 << AMS_DELTA_GPIO_PIN_MODEM_IRQ)
	#define HOOK_SWITCH_MASK (0x1 << AMS_DELTA_GPIO_PIN_HOOK_SWITCH)
	#define OTHERS_MASK (MODEM_IRQ_MASK \| HOOK_SWITCH_MASK)

	/* IRQ handler register bitmasks */
	#define DEFERRED_FIQ_MASK OMAP_IRQ_BIT(INT_DEFERRED_FIQ)
	#define GPIO_BANK1_MASK OMAP_IRQ_BIT(INT_GPIO_BANK1)

	/* Driver buffer byte offsets */
	#define BUF_MASK (FIQ_MASK * 4)
	#define BUF_STATE (FIQ_STATE * 4)
	#define BUF_KEYS_CNT (FIQ_KEYS_CNT * 4)
	#define BUF_TAIL_OFFSET (FIQ_TAIL_OFFSET * 4)
	#define BUF_HEAD_OFFSET (FIQ_HEAD_OFFSET * 4)
	#define BUF_BUF_LEN (FIQ_BUF_LEN * 4)
	#define BUF_KEY (FIQ_KEY * 4)
	#define BUF_MISSED_KEYS (FIQ_MISSED_KEYS * 4)
	#define BUF_BUFFER_START (FIQ_BUFFER_START * 4)
	#define BUF_GPIO_INT_MASK (FIQ_GPIO_INT_MASK * 4)
	#define BUF_KEYS_HICNT (FIQ_KEYS_HICNT * 4)
	#define BUF_IRQ_PEND (FIQ_IRQ_PEND * 4)
	#define BUF_SIR_CODE_L1 (FIQ_SIR_CODE_L1 * 4)
	#define BUF_SIR_CODE_L2 (IRQ_SIR_CODE_L2 * 4)
	#define BUF_CNT_INT_00 (FIQ_CNT_INT_00 * 4)
	#define BUF_CNT_INT_KEY (FIQ_CNT_INT_KEY * 4)
	#define BUF_CNT_INT_MDM (FIQ_CNT_INT_MDM * 4)
	#define BUF_CNT_INT_03 (FIQ_CNT_INT_03 * 4)
	#define BUF_CNT_INT_HSW (FIQ_CNT_INT_HSW * 4)
	#define BUF_CNT_INT_05 (FIQ_CNT_INT_05 * 4)
	#define BUF_CNT_INT_06 (FIQ_CNT_INT_06 * 4)
	#define BUF_CNT_INT_07 (FIQ_CNT_INT_07 * 4)
	#define BUF_CNT_INT_08 (FIQ_CNT_INT_08 * 4)
	#define BUF_CNT_INT_09 (FIQ_CNT_INT_09 * 4)
	#define BUF_CNT_INT_10 (FIQ_CNT_INT_10 * 4)
	#define BUF_CNT_INT_11 (FIQ_CNT_INT_11 * 4)
	#define BUF_CNT_INT_12 (FIQ_CNT_INT_12 * 4)
	#define BUF_CNT_INT_13 (FIQ_CNT_INT_13 * 4)
	#define BUF_CNT_INT_14 (FIQ_CNT_INT_14 * 4)
	#define BUF_CNT_INT_15 (FIQ_CNT_INT_15 * 4)
	#define BUF_CIRC_BUFF (FIQ_CIRC_BUFF * 4)


	/*
	* Register usage
	* r8 - temporary
	* r9 - the driver buffer
	* r10 - temporary
	* r11 - interrupts mask
	* r12 - base pointers
	* r13 - interrupts status
	*/

	.text

	.global qwerty_fiqin_end

	ENTRY(qwerty_fiqin_start)
	@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
	@ FIQ intrrupt handler
	ldr r12, omap_ih1_base @ set pointer to level1 handler

	ldr r11, [r12, #IRQ_MIR_REG_OFFSET] @ fetch interrupts mask

	ldr r13, [r12, #IRQ_ITR_REG_OFFSET] @ fetch interrupts status
	bics r13, r13, r11 @ clear masked - any left?
	beq exit @ none - spurious FIQ? exit

	ldr r10, [r12, #IRQ_SIR_FIQ_REG_OFFSET] @ get requested interrupt number

	mov r8, #2 @ reset FIQ agreement
	str r8, [r12, #IRQ_CONTROL_REG_OFFSET]

	cmp r10, #(INT_GPIO_BANK1 - NR_IRQS_LEGACY) @ is it GPIO interrupt?
	beq gpio @ yes - process it

	mov r8, #1
	orr r8, r11, r8, lsl r10 @ mask spurious interrupt
	str r8, [r12, #IRQ_MIR_REG_OFFSET]
	exit:
	subs pc, lr, #4 @ return from FIQ
	@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@


	@@@@@@@@@@@@@@@@@@@@@@@@@@@
	gpio: @ GPIO bank interrupt handler
	ldr r12, omap1510_gpio_base @ set base pointer to GPIO bank

	ldr r11, [r12, #OMAP1510_GPIO_INT_MASK] @ fetch GPIO interrupts mask
	restart:
	ldr r13, [r12, #OMAP1510_GPIO_INT_STATUS] @ fetch status bits
	bics r13, r13, r11 @ clear masked - any left?
	beq exit @ no - spurious interrupt? exit

	orr r11, r11, r13 @ mask all requested interrupts
	str r11, [r12, #OMAP1510_GPIO_INT_MASK]

	str r13, [r12, #OMAP1510_GPIO_INT_STATUS] @ ack all requested interrupts

	ands r10, r13, #KEYBRD_CLK_MASK @ extract keyboard status - set?
	beq hksw @ no - try next source


	@@@@@@@@@@@@@@@@@@@@@@
	@ Keyboard clock FIQ mode interrupt handler
	@ r10 now contains KEYBRD_CLK_MASK, use it
	bic r11, r11, r10 @ unmask it
	str r11, [r12, #OMAP1510_GPIO_INT_MASK]

	@ Process keyboard data
	ldr r8, [r12, #OMAP1510_GPIO_DATA_INPUT] @ fetch GPIO input

	ldr r10, [r9, #BUF_STATE] @ fetch kbd interface state
	cmp r10, #0 @ are we expecting start bit?
	bne data @ no - go to data processing

	ands r8, r8, #KEYBRD_DATA_MASK @ check start bit - detected?
	beq hksw @ no - try next source

	@ r8 contains KEYBRD_DATA_MASK, use it
	str r8, [r9, #BUF_STATE] @ enter data processing state
	@ r10 already contains 0, reuse it
	str r10, [r9, #BUF_KEY] @ clear keycode
	mov r10, #2 @ reset input bit mask
	str r10, [r9, #BUF_MASK]

	@ Mask other GPIO line interrupts till key done
	str r11, [r9, #BUF_GPIO_INT_MASK] @ save mask for later restore
	mvn r11, #KEYBRD_CLK_MASK @ prepare all except kbd mask
	str r11, [r12, #OMAP1510_GPIO_INT_MASK] @ store into the mask register

	b restart @ restart

	data: ldr r10, [r9, #BUF_MASK] @ fetch current input bit mask

	@ r8 still contains GPIO input bits
	ands r8, r8, #KEYBRD_DATA_MASK @ is keyboard data line low?
	ldreq r8, [r9, #BUF_KEY] @ yes - fetch collected so far,
	orreq r8, r8, r10 @ set 1 at current mask position
	streq r8, [r9, #BUF_KEY] @ and save back

	mov r10, r10, lsl #1 @ shift mask left
	bics r10, r10, #0x800 @ have we got all the bits?
	strne r10, [r9, #BUF_MASK] @ not yet - store the mask
	bne restart @ and restart

	@ r10 already contains 0, reuse it
	str r10, [r9, #BUF_STATE] @ reset state to start

	@ Key done - restore interrupt mask
	ldr r10, [r9, #BUF_GPIO_INT_MASK] @ fetch saved mask
	and r11, r11, r10 @ unmask all saved as unmasked
	str r11, [r12, #OMAP1510_GPIO_INT_MASK] @ restore into the mask register

	@ Try appending the keycode to the circular buffer
	ldr r10, [r9, #BUF_KEYS_CNT] @ get saved keystrokes count
	ldr r8, [r9, #BUF_BUF_LEN] @ get buffer size
	cmp r10, r8 @ is buffer full?
	beq hksw @ yes - key lost, next source

	add r10, r10, #1 @ incremet keystrokes counter
	str r10, [r9, #BUF_KEYS_CNT]

	ldr r10, [r9, #BUF_TAIL_OFFSET] @ get buffer tail offset
	@ r8 already contains buffer size
	cmp r10, r8 @ end of buffer?
	moveq r10, #0 @ yes - rewind to buffer start

	ldr r12, [r9, #BUF_BUFFER_START] @ get buffer start address
	add r12, r12, r10, LSL #2 @ calculate buffer tail address
	ldr r8, [r9, #BUF_KEY] @ get last keycode
	str r8, [r12] @ append it to the buffer tail

	add r10, r10, #1 @ increment buffer tail offset
	str r10, [r9, #BUF_TAIL_OFFSET]

	ldr r10, [r9, #BUF_CNT_INT_KEY] @ increment interrupts counter
	add r10, r10, #1
	str r10, [r9, #BUF_CNT_INT_KEY]
	@@@@@@@@@@@@@@@@@@@@@@@@


	hksw: @Is hook switch interrupt requested?
	tst r13, #HOOK_SWITCH_MASK @ is hook switch status bit set?
	beq mdm @ no - try next source


	@@@@@@@@@@@@@@@@@@@@@@@@
	@ Hook switch interrupt FIQ mode simple handler

	@ Don't toggle active edge, the switch always bounces

	@ Increment hook switch interrupt counter
	ldr r10, [r9, #BUF_CNT_INT_HSW]
	add r10, r10, #1
	str r10, [r9, #BUF_CNT_INT_HSW]
	@@@@@@@@@@@@@@@@@@@@@@@@


	mdm: @Is it a modem interrupt?
	tst r13, #MODEM_IRQ_MASK @ is modem status bit set?
	beq irq @ no - check for next interrupt


	@@@@@@@@@@@@@@@@@@@@@@@@
	@ Modem FIQ mode interrupt handler stub

	@ Increment modem interrupt counter
	ldr r10, [r9, #BUF_CNT_INT_MDM]
	add r10, r10, #1
	str r10, [r9, #BUF_CNT_INT_MDM]
	@@@@@@@@@@@@@@@@@@@@@@@@


	irq: @ Place deferred_fiq interrupt request
	ldr r12, deferred_fiq_ih_base @ set pointer to IRQ handler
	mov r10, #DEFERRED_FIQ_MASK @ set deferred_fiq bit
	str r10, [r12, #IRQ_ISR_REG_OFFSET] @ place it in the ISR register

	ldr r12, omap1510_gpio_base @ set pointer back to GPIO bank
	b restart @ check for next GPIO interrupt
	@@@@@@@@@@@@@@@@@@@@@@@@@@@


	/*
	* Virtual addresses for IO
	*/
	omap_ih1_base:
	.word OMAP1_IO_ADDRESS(OMAP_IH1_BASE)
	deferred_fiq_ih_base:
	.word OMAP1_IO_ADDRESS(DEFERRED_FIQ_IH_BASE)
	omap1510_gpio_base:
	.word OMAP1_IO_ADDRESS(OMAP1510_GPIO_BASE)
	qwerty_fiqin_end:

	/*
	* Check the size of the FIQ,
	* it cannot go beyond 0xffff0200, and is copied to 0xffff001c
	*/
	.if (qwerty_fiqin_end - qwerty_fiqin_start) > (0x200 - 0x1c)
	.err
	.endif