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author | Janusz Krzysztofik <jkrzyszt@tis.icnet.pl> | 2010-04-28 01:01:29 +0000 |
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committer | Tony Lindgren <tony@atomide.com> | 2010-05-05 11:11:10 -0700 |
commit | 60c3bf3f1215453a4f30f0b91db7fd301d558693 (patch) | |
tree | 14d56bfb91cedb836481b3ab820012f11484235c /arch/arm/mach-omap1/ams-delta-fiq-handler.S | |
parent | 1c4da2b737cce57f0c17344cda7f9ba1d206bfa5 (diff) | |
download | linux-60c3bf3f1215453a4f30f0b91db7fd301d558693.tar.gz linux-60c3bf3f1215453a4f30f0b91db7fd301d558693.tar.bz2 linux-60c3bf3f1215453a4f30f0b91db7fd301d558693.zip |
OMAP1: Amstrad Delta: add FIQ handler for serial keyboardport interrupt processing
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.
Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Diffstat (limited to 'arch/arm/mach-omap1/ams-delta-fiq-handler.S')
-rw-r--r-- | arch/arm/mach-omap1/ams-delta-fiq-handler.S | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/arch/arm/mach-omap1/ams-delta-fiq-handler.S b/arch/arm/mach-omap1/ams-delta-fiq-handler.S new file mode 100644 index 000000000000..927d5a181760 --- /dev/null +++ b/arch/arm/mach-omap1/ams-delta-fiq-handler.S @@ -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 |