--- /dev/null
+/*
+ * 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);
+}
git.samba.org / sfrench / cifs-2.6.git / commitdiff