MIPS: PowerTV: Base files for Cisco PowerTV platform

Add the Cisco Powertv cable settop box to the MIPS tree. This platform is
based on a MIPS 24Kc processor with various devices integrated on the same
ASIC. There are multiple models of this box, with differing configuration
but the same kernel runs across the product line.

Signed-off-by: David VomLehn <dvomlehn@cisco.com>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/132/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 125 insertions, 0 deletions

diff --git a/arch/mips/powertv/asic/asic_int.c b/arch/mips/powertv/asic/asic_int.c
new file mode 100644
index 000000000000..80b2eed21ac3
--- /dev/null
+++ b/arch/mips/powertv/asic/asic_int.c
@@ -0,0 +1,125 @@
+/*
+ * Carsten Langgaard, carstenl@mips.com
+ * Copyright (C) 2000, 2001, 2004 MIPS Technologies, Inc.
+ * Copyright (C) 2001 Ralf Baechle
+ * Portions copyright (C) 2009  Cisco Systems, Inc.
+ *
+ *  This program is free software; you can distribute it and/or modify it
+ *  under the terms of the GNU General Public License (Version 2) as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope 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.,
+ *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
+ *
+ * Routines for generic manipulation of the interrupts found on the PowerTV
+ * platform.
+ *
+ * The interrupt controller is located in the South Bridge a PIIX4 device
+ * with two internal 82C95 interrupt controllers.
+ */
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/kernel_stat.h>
+#include <linux/kernel.h>
+#include <linux/random.h>
+
+#include <asm/irq_cpu.h>
+#include <linux/io.h>
+#include <asm/irq_regs.h>
+#include <asm/mips-boards/generic.h>
+
+#include <asm/mach-powertv/asic_regs.h>
+
+static DEFINE_SPINLOCK(asic_irq_lock);
+
+static inline int get_int(void)
+{
+	unsigned long flags;
+	int irq;
+
+	spin_lock_irqsave(&asic_irq_lock, flags);
+
+	irq = (asic_read(int_int_scan) >> 4) - 1;
+
+	if (irq == 0 || irq >= NR_IRQS)
+		irq = -1;
+
+	spin_unlock_irqrestore(&asic_irq_lock, flags);
+
+	return irq;
+}
+
+static void asic_irqdispatch(void)
+{
+	int irq;
+
+	irq = get_int();
+	if (irq < 0)
+		return;  /* interrupt has already been cleared */
+
+	do_IRQ(irq);
+}
+
+static inline int clz(unsigned long x)
+{
+	__asm__(
+	"	.set	push					\n"
+	"	.set	mips32					\n"
+	"	clz	%0, %1					\n"
+	"	.set	pop					\n"
+	: "=r" (x)
+	: "r" (x));
+
+	return x;
+}
+
+/*
+ * Version of ffs that only looks at bits 12..15.
+ */
+static inline unsigned int irq_ffs(unsigned int pending)
+{
+	return fls(pending) - 1 + CAUSEB_IP;
+}
+
+/*
+ * TODO: check how it works under EIC mode.
+ */
+asmlinkage void plat_irq_dispatch(void)
+{
+	unsigned int pending = read_c0_cause() & read_c0_status() & ST0_IM;
+	int irq;
+
+	irq = irq_ffs(pending);
+
+	if (irq == CAUSEF_IP3)
+		asic_irqdispatch();
+	else if (irq >= 0)
+		do_IRQ(irq);
+	else
+		spurious_interrupt();
+}
+
+void __init arch_init_irq(void)
+{
+	int i;
+
+	asic_irq_init();
+
+	/*
+	 * Initialize interrupt exception vectors.
+	 */
+	if (cpu_has_veic || cpu_has_vint) {
+		int nvec = cpu_has_veic ? 64 : 8;
+		for (i = 0; i < nvec; i++)
+			set_vi_handler(i, asic_irqdispatch);
+	}
+}