This patch introduces a Fast Interrupt Request (FIQ) handler for Amstrad Delta (E3) videophone. The handler's purpose is to process interrupts generated by a GPIO line that a serial keyboard clock hangs off. It collects consecutive bits into words, pushing them into a buffer, then requests a higher level interrupt after one or more words are ready for further processing by a keyboard port driver.
The handler also processes interrupts generated by two other GPIO lines, used by other on-board supported devices, by simply requesting a higher level interrupt, that in turn should invoke those device's specific irq handlers.
IRQ12 line, not used by OMAP1510 hardware (described as reserved), has been choosen as a higher level interrupt source.
Created and tested against linux-omap master, commit 104a77440f05430f29f9d3f4ecb88c1536819585 dated 2010-04-27.
Compiles on top of PATCH v4 0.1/5(7), "OMAP: add missing FIQ_START definition required for arch/arm/kernel/fiq.c compilation".
Compile tested with a bunch of OMAP15XX/OMAP16XX boards selected simultaneously.
Signed-off-by: Janusz Krzysztofik jkrzyszt@tis.icnet.pl --- v2 changes: - no functional changes, - refresh against linux-2.6.34-rc2. v3 changes: - assembler code optimizations suggested by Ralph Corderoy, - (re)use existing header file provided macros where applicable instead of defining new (from scratch); remove a lot of unnecessary defines, - follow default OMAP GPIO interrupt processing path more closely, - prepare for choosing arbitrary IRQ for deferred_fiq handler; use IRQ12 (reserved on OMAP1510) instead of Timer 32K dedicated IRQ, - more optimizations for smaller code. v4 changes: - correct a few occurrences of 2nd argumet missing in 3-argument assembly instruction, thanks to Ralph Corderoy for pointing them out, - remove commented out code for interrupt active edge toggling, but keep the updated comment that justifies the removal.
arch/arm/mach-omap1/Kconfig | 10 arch/arm/mach-omap1/Makefile | 1 arch/arm/mach-omap1/ams-delta-fiq-handler.S | 278 +++++++++++++++++++++++ arch/arm/mach-omap1/include/mach/ams-delta-fiq.h | 72 +++++ 4 files changed, 361 insertions(+)
diff -uprN git.orig/arch/arm/mach-omap1/Kconfig git/arch/arm/mach-omap1/Kconfig --- git.orig/arch/arm/mach-omap1/Kconfig 2010-04-27 21:40:22.000000000 +0200 +++ git/arch/arm/mach-omap1/Kconfig 2010-04-27 22:23:41.000000000 +0200 @@ -152,6 +152,16 @@ config MACH_AMS_DELTA Support for the Amstrad E3 (codename Delta) videophone. Say Y here if you have such a device.
+config AMS_DELTA_FIQ + bool "Fast Interrupt Request (FIQ) support for the E3" + depends on MACH_AMS_DELTA + select FIQ + help + Provide a FIQ handler for the E3. + This allows for fast handling of interrupts generated + by the clock line of the E3 mailboard (or a PS/2 keyboard) + connected to the GPIO based external keyboard port. + config MACH_OMAP_GENERIC bool "Generic OMAP board" depends on ARCH_OMAP1 && (ARCH_OMAP15XX || ARCH_OMAP16XX) diff -uprN git.orig/arch/arm/mach-omap1/Makefile git/arch/arm/mach-omap1/Makefile --- git.orig/arch/arm/mach-omap1/Makefile 2010-04-27 21:40:22.000000000 +0200 +++ git/arch/arm/mach-omap1/Makefile 2010-04-27 22:23:41.000000000 +0200 @@ -37,6 +37,7 @@ obj-$(CONFIG_MACH_OMAP_PALMZ71) += boar obj-$(CONFIG_MACH_OMAP_PALMTT) += board-palmtt.o obj-$(CONFIG_MACH_NOKIA770) += board-nokia770.o obj-$(CONFIG_MACH_AMS_DELTA) += board-ams-delta.o +obj-$(CONFIG_AMS_DELTA_FIQ) += ams-delta-fiq-handler.o obj-$(CONFIG_MACH_SX1) += board-sx1.o board-sx1-mmc.o obj-$(CONFIG_MACH_HERALD) += board-htcherald.o
diff -uprN git.orig/arch/arm/mach-omap1/ams-delta-fiq-handler.S git/arch/arm/mach-omap1/ams-delta-fiq-handler.S --- git.orig/arch/arm/mach-omap1/ams-delta-fiq-handler.S 1970-01-01 01:00:00.000000000 +0100 +++ git/arch/arm/mach-omap1/ams-delta-fiq-handler.S 2010-04-27 22:23:41.000000000 +0200 @@ -0,0 +1,278 @@ +/* + * 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 + * + * 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 <plat/io.h> +#include <plat/board-ams-delta.h> + +#include <mach/ams-delta-fiq.h> + +/* + * GPIO related definitions, copied from arch/arm/plat-omap/gpio.c. + * Unfortunately, those were not placed in a separate header file. + */ +#define OMAP1510_GPIO_BASE 0xFFFCE000 +#define OMAP1510_GPIO_DATA_INPUT 0x00 +#define OMAP1510_GPIO_DATA_OUTPUT 0x04 +#define OMAP1510_GPIO_DIR_CONTROL 0x08 +#define OMAP1510_GPIO_INT_CONTROL 0x0c +#define OMAP1510_GPIO_INT_MASK 0x10 +#define OMAP1510_GPIO_INT_STATUS 0x14 +#define OMAP1510_GPIO_PIN_CONTROL 0x18 + +/* 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 (0x1 << (INT_DEFERRED_FIQ % IH2_BASE)) +#define GPIO_BANK1_MASK (0x1 << 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 useage + * 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 @ is it GPIO bank 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] + + 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 + str r10, [r12, #OMAP1510_GPIO_INT_STATUS] @ ack the interrupt + 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 diff -uprN git.orig/arch/arm/mach-omap1/include/mach/ams-delta-fiq.h git/arch/arm/mach-omap1/include/mach/ams-delta-fiq.h --- git.orig/arch/arm/mach-omap1/include/mach/ams-delta-fiq.h 1970-01-01 01:00:00.000000000 +0100 +++ git/arch/arm/mach-omap1/include/mach/ams-delta-fiq.h 2010-04-27 22:23:41.000000000 +0200 @@ -0,0 +1,72 @@ +/* + * arch/arm/mach-omap1/include/ams-delta-fiq.h + * + * Taken from the original Amstrad modifications to fiq.h + * + * Copyright (c) 2004 Amstrad Plc + * Copyright (c) 2006 Matt Callow + * Copyright (c) 2010 Janusz Krzysztofik + * + * 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. + */ +#ifndef __AMS_DELTA_FIQ_H +#define __AMS_DELTA_FIQ_H + +#include <plat/irqs.h> + +/* + * Interrupt number used for passing control from FIQ to IRQ. + * IRQ12, described as reserved, has been selected. + */ +#define INT_DEFERRED_FIQ INT_1510_RES12 +/* + * Base address of an interrupt handler that the INT_DEFERRED_FIQ belongs to. + */ +#if (INT_DEFERRED_FIQ < IH2_BASE) +#define DEFERRED_FIQ_IH_BASE OMAP_IH1_BASE +#else +#define DEFERRED_FIQ_IH_BASE OMAP_IH2_BASE +#endif + +/* + * These are the offsets from the begining of the fiq_buffer. They are put here + * since the buffer and header need to be accessed by drivers servicing devices + * which generate GPIO interrupts - e.g. keyboard, modem, hook switch. + */ +#define FIQ_MASK 0 +#define FIQ_STATE 1 +#define FIQ_KEYS_CNT 2 +#define FIQ_TAIL_OFFSET 3 +#define FIQ_HEAD_OFFSET 4 +#define FIQ_BUF_LEN 5 +#define FIQ_KEY 6 +#define FIQ_MISSED_KEYS 7 +#define FIQ_BUFFER_START 8 +#define FIQ_GPIO_INT_MASK 9 +#define FIQ_KEYS_HICNT 10 +#define FIQ_IRQ_PEND 11 +#define FIQ_SIR_CODE_L1 12 +#define IRQ_SIR_CODE_L2 13 + +#define FIQ_CNT_INT_00 14 +#define FIQ_CNT_INT_KEY 15 +#define FIQ_CNT_INT_MDM 16 +#define FIQ_CNT_INT_03 17 +#define FIQ_CNT_INT_HSW 18 +#define FIQ_CNT_INT_05 19 +#define FIQ_CNT_INT_06 20 +#define FIQ_CNT_INT_07 21 +#define FIQ_CNT_INT_08 22 +#define FIQ_CNT_INT_09 23 +#define FIQ_CNT_INT_10 24 +#define FIQ_CNT_INT_11 25 +#define FIQ_CNT_INT_12 26 +#define FIQ_CNT_INT_13 27 +#define FIQ_CNT_INT_14 28 +#define FIQ_CNT_INT_15 29 + +#define FIQ_CIRC_BUFF 30 /*Start of circular buffer */ + +#endif