[MIPS] Add GT641xx IRQ routines.

Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 131 insertions, 0 deletions

diff --git a/arch/mips/kernel/irq-gt641xx.c b/arch/mips/kernel/irq-gt641xx.c
new file mode 100644
index 00000000000..1b81b131f43
--- /dev/null
+++ b/arch/mips/kernel/irq-gt641xx.c
@@ -0,0 +1,131 @@
+/*
+ *  GT641xx IRQ routines.
+ *
+ *  Copyright (C) 2007  Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+#include <linux/hardirq.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#include <asm/gt64120.h>
+
+#define GT641XX_IRQ_TO_BIT(irq)	(1U << (irq - GT641XX_IRQ_BASE))
+
+static DEFINE_SPINLOCK(gt641xx_irq_lock);
+
+static void ack_gt641xx_irq(unsigned int irq)
+{
+	unsigned long flags;
+	u32 cause;
+
+	spin_lock_irqsave(&gt641xx_irq_lock, flags);
+	cause = GT_READ(GT_INTRCAUSE_OFS);
+	cause &= ~GT641XX_IRQ_TO_BIT(irq);
+	GT_WRITE(GT_INTRCAUSE_OFS, cause);
+	spin_unlock_irqrestore(&gt641xx_irq_lock, flags);
+}
+
+static void mask_gt641xx_irq(unsigned int irq)
+{
+	unsigned long flags;
+	u32 mask;
+
+	spin_lock_irqsave(&gt641xx_irq_lock, flags);
+	mask = GT_READ(GT_INTRMASK_OFS);
+	mask &= ~GT641XX_IRQ_TO_BIT(irq);
+	GT_WRITE(GT_INTRMASK_OFS, mask);
+	spin_unlock_irqrestore(&gt641xx_irq_lock, flags);
+}
+
+static void mask_ack_gt641xx_irq(unsigned int irq)
+{
+	unsigned long flags;
+	u32 cause, mask;
+
+	spin_lock_irqsave(&gt641xx_irq_lock, flags);
+	mask = GT_READ(GT_INTRMASK_OFS);
+	mask &= ~GT641XX_IRQ_TO_BIT(irq);
+	GT_WRITE(GT_INTRMASK_OFS, mask);
+
+	cause = GT_READ(GT_INTRCAUSE_OFS);
+	cause &= ~GT641XX_IRQ_TO_BIT(irq);
+	GT_WRITE(GT_INTRCAUSE_OFS, cause);
+	spin_unlock_irqrestore(&gt641xx_irq_lock, flags);
+}
+
+static void unmask_gt641xx_irq(unsigned int irq)
+{
+	unsigned long flags;
+	u32 mask;
+
+	spin_lock_irqsave(&gt641xx_irq_lock, flags);
+	mask = GT_READ(GT_INTRMASK_OFS);
+	mask |= GT641XX_IRQ_TO_BIT(irq);
+	GT_WRITE(GT_INTRMASK_OFS, mask);
+	spin_unlock_irqrestore(&gt641xx_irq_lock, flags);
+}
+
+static struct irq_chip gt641xx_irq_chip = {
+	.name		= "GT641xx",
+	.ack		= ack_gt641xx_irq,
+	.mask		= mask_gt641xx_irq,
+	.mask_ack	= mask_ack_gt641xx_irq,
+	.unmask		= unmask_gt641xx_irq,
+};
+
+void gt641xx_irq_dispatch(void)
+{
+	u32 cause, mask;
+	int i;
+
+	cause = GT_READ(GT_INTRCAUSE_OFS);
+	mask = GT_READ(GT_INTRMASK_OFS);
+	cause &= mask;
+
+	/*
+	 * bit0 : logical or of all the interrupt bits.
+	 * bit30: logical or of bits[29:26,20:1].
+	 * bit31: logical or of bits[25:1].
+	 */
+	for (i = 1; i < 30; i++) {
+		if (cause & (1U << i)) {
+			do_IRQ(GT641XX_IRQ_BASE + i);
+			return;
+		}
+	}
+
+	atomic_inc(&irq_err_count);
+}
+
+void __init gt641xx_irq_init(void)
+{
+	int i;
+
+	GT_WRITE(GT_INTRMASK_OFS, 0);
+	GT_WRITE(GT_INTRCAUSE_OFS, 0);
+
+	/*
+	 * bit0 : logical or of all the interrupt bits.
+	 * bit30: logical or of bits[29:26,20:1].
+	 * bit31: logical or of bits[25:1].
+	 */
+	for (i = 1; i < 30; i++)
+		set_irq_chip_and_handler(GT641XX_IRQ_BASE + i,
+		                         &gt641xx_irq_chip, handle_level_irq);
+}