Initial import

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 000000000..d1f12095f
--- /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 <mach/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)
+{
+	int gpio, irq_num, fiq_count;
+	struct irq_chip *irq_chip;
+
+	irq_chip = irq_get_chip(gpio_to_irq(AMS_DELTA_GPIO_PIN_KEYBRD_CLK));
+
+	/*
+	 * 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) {
+				struct irq_data *d = irq_get_irq_data(irq_num);
+
+				/*
+				 * It looks like handle_edge_irq() that
+				 * OMAP GPIO edge interrupts default to,
+				 * expects interrupt already unmasked.
+				 */
+				if (irq_chip && irq_chip->irq_unmask)
+					irq_chip->irq_unmask(d);
+			}
+			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", NULL);
+	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);
+}