diff options
Diffstat (limited to 'arch/arm/mach-omap1/ams-delta-fiq.c')
| -rw-r--r-- | arch/arm/mach-omap1/ams-delta-fiq.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/arch/arm/mach-omap1/ams-delta-fiq.c b/arch/arm/mach-omap1/ams-delta-fiq.c new file mode 100644 index 000000000000..6c994e2d8879 --- /dev/null +++ b/arch/arm/mach-omap1/ams-delta-fiq.c @@ -0,0 +1,155 @@ +/* + * Amstrad E3 FIQ handling + * + * Copyright (C) 2009 Janusz Krzysztofik + * Copyright (c) 2006 Matt Callow + * Copyright (c) 2004 Amstrad Plc + * Copyright (C) 2001 RidgeRun, Inc. + * + * Parts of this code are taken from linux/arch/arm/mach-omap/irq.c + * in the MontaVista 2.4 kernel (and the Amstrad changes therein) + * + * 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/gpio.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/module.h> +#include <linux/io.h> + +#include <plat/board-ams-delta.h> + +#include <asm/fiq.h> +#include <mach/ams-delta-fiq.h> + +static struct fiq_handler fh = { + .name = "ams-delta-fiq" +}; + +/* + * This buffer is shared between FIQ and IRQ contexts. + * The FIQ and IRQ isrs can both read and write it. + * It is structured as a header section several 32bit slots, + * followed by the circular buffer where the FIQ isr stores + * keystrokes received from the qwerty keyboard. + * See ams-delta-fiq.h for details of offsets. + */ +unsigned int fiq_buffer[1024]; +EXPORT_SYMBOL(fiq_buffer); + +static unsigned int irq_counter[16]; + +static irqreturn_t deferred_fiq(int irq, void *dev_id) +{ + struct irq_desc *irq_desc; + struct irq_chip *irq_chip = NULL; + int gpio, irq_num, fiq_count; + + irq_desc = irq_to_desc(IH_GPIO_BASE); + if (irq_desc) + irq_chip = irq_desc->chip; + + /* + * For each handled GPIO interrupt, keep calling its interrupt handler + * until the IRQ counter catches the FIQ incremented interrupt counter. + */ + for (gpio = AMS_DELTA_GPIO_PIN_KEYBRD_CLK; + gpio <= AMS_DELTA_GPIO_PIN_HOOK_SWITCH; gpio++) { + irq_num = gpio_to_irq(gpio); + fiq_count = fiq_buffer[FIQ_CNT_INT_00 + gpio]; + + while (irq_counter[gpio] < fiq_count) { + if (gpio != AMS_DELTA_GPIO_PIN_KEYBRD_CLK) { + /* + * It looks like handle_edge_irq() that + * OMAP GPIO edge interrupts default to, + * expects interrupt already unmasked. + */ + if (irq_chip && irq_chip->unmask) + irq_chip->unmask(irq_num); + } + generic_handle_irq(irq_num); + + irq_counter[gpio]++; + } + } + return IRQ_HANDLED; +} + +void __init ams_delta_init_fiq(void) +{ + void *fiqhandler_start; + unsigned int fiqhandler_length; + struct pt_regs FIQ_regs; + unsigned long val, offset; + int i, retval; + + fiqhandler_start = &qwerty_fiqin_start; + fiqhandler_length = &qwerty_fiqin_end - &qwerty_fiqin_start; + pr_info("Installing fiq handler from %p, length 0x%x\n", + fiqhandler_start, fiqhandler_length); + + retval = claim_fiq(&fh); + if (retval) { + pr_err("ams_delta_init_fiq(): couldn't claim FIQ, ret=%d\n", + retval); + return; + } + + retval = request_irq(INT_DEFERRED_FIQ, deferred_fiq, + IRQ_TYPE_EDGE_RISING, "deferred_fiq", 0); + if (retval < 0) { + pr_err("Failed to get deferred_fiq IRQ, ret=%d\n", retval); + release_fiq(&fh); + return; + } + /* + * Since no set_type() method is provided by OMAP irq chip, + * switch to edge triggered interrupt type manually. + */ + offset = IRQ_ILR0_REG_OFFSET + INT_DEFERRED_FIQ * 0x4; + val = omap_readl(DEFERRED_FIQ_IH_BASE + offset) & ~(1 << 1); + omap_writel(val, DEFERRED_FIQ_IH_BASE + offset); + + set_fiq_handler(fiqhandler_start, fiqhandler_length); + + /* + * Initialise the buffer which is shared + * between FIQ mode and IRQ mode + */ + fiq_buffer[FIQ_GPIO_INT_MASK] = 0; + fiq_buffer[FIQ_MASK] = 0; + fiq_buffer[FIQ_STATE] = 0; + fiq_buffer[FIQ_KEY] = 0; + fiq_buffer[FIQ_KEYS_CNT] = 0; + fiq_buffer[FIQ_KEYS_HICNT] = 0; + fiq_buffer[FIQ_TAIL_OFFSET] = 0; + fiq_buffer[FIQ_HEAD_OFFSET] = 0; + fiq_buffer[FIQ_BUF_LEN] = 256; + fiq_buffer[FIQ_MISSED_KEYS] = 0; + fiq_buffer[FIQ_BUFFER_START] = + (unsigned int) &fiq_buffer[FIQ_CIRC_BUFF]; + + for (i = FIQ_CNT_INT_00; i <= FIQ_CNT_INT_15; i++) + fiq_buffer[i] = 0; + + /* + * FIQ mode r9 always points to the fiq_buffer, becauses the FIQ isr + * will run in an unpredictable context. The fiq_buffer is the FIQ isr's + * only means of communication with the IRQ level and other kernel + * context code. + */ + FIQ_regs.ARM_r9 = (unsigned int)fiq_buffer; + set_fiq_regs(&FIQ_regs); + + pr_info("request_fiq(): fiq_buffer = %p\n", fiq_buffer); + + /* + * Redirect GPIO interrupts to FIQ + */ + offset = IRQ_ILR0_REG_OFFSET + INT_GPIO_BANK1 * 0x4; + val = omap_readl(OMAP_IH1_BASE + offset) | 1; + omap_writel(val, OMAP_IH1_BASE + offset); +} |