[MIPS] Add back support for LASAT platforms

Signed-off-by: Brian Murphy <brian@murphy.dk>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 130 insertions, 0 deletions

diff --git a/arch/mips/lasat/interrupt.c b/arch/mips/lasat/interrupt.c
new file mode 100644
index 000000000000..5f35289bfff5
--- /dev/null
+++ b/arch/mips/lasat/interrupt.c
@@ -0,0 +1,130 @@
+/*
+ * Carsten Langgaard, carstenl@mips.com
+ * Copyright (C) 1999,2000 MIPS Technologies, Inc.  All rights reserved.
+ *
+ *  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
+ * Lasat boards.
+ */
+#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 <asm/bootinfo.h>
+#include <asm/lasat/lasatint.h>
+#include <asm/time.h>
+#include <asm/gdb-stub.h>
+
+static volatile int *lasat_int_status;
+static volatile int *lasat_int_mask;
+static volatile int lasat_int_mask_shift;
+
+void disable_lasat_irq(unsigned int irq_nr)
+{
+	*lasat_int_mask &= ~(1 << irq_nr) << lasat_int_mask_shift;
+}
+
+void enable_lasat_irq(unsigned int irq_nr)
+{
+	*lasat_int_mask |= (1 << irq_nr) << lasat_int_mask_shift;
+}
+
+static struct irq_chip lasat_irq_type = {
+	.name = "Lasat",
+	.ack = disable_lasat_irq,
+	.mask = disable_lasat_irq,
+	.mask_ack = disable_lasat_irq,
+	.unmask = enable_lasat_irq,
+};
+
+static inline int ls1bit32(unsigned int x)
+{
+	int b = 31, s;
+
+	s = 16; if (x << 16 == 0) s = 0; b -= s; x <<= s;
+	s =  8; if (x <<  8 == 0) s = 0; b -= s; x <<= s;
+	s =  4; if (x <<  4 == 0) s = 0; b -= s; x <<= s;
+	s =  2; if (x <<  2 == 0) s = 0; b -= s; x <<= s;
+	s =  1; if (x <<  1 == 0) s = 0; b -= s;
+
+	return b;
+}
+
+static unsigned long (*get_int_status)(void);
+
+static unsigned long get_int_status_100(void)
+{
+	return *lasat_int_status & *lasat_int_mask;
+}
+
+static unsigned long get_int_status_200(void)
+{
+	unsigned long int_status;
+
+	int_status = *lasat_int_status;
+	int_status &= (int_status >> LASATINT_MASK_SHIFT_200) & 0xffff;
+	return int_status;
+}
+
+asmlinkage void plat_irq_dispatch(void)
+{
+	unsigned long int_status;
+	unsigned int cause = read_c0_cause();
+	int irq;
+
+	if (cause & CAUSEF_IP7) {	/* R4000 count / compare IRQ */
+		ll_timer_interrupt(7);
+		return;
+	}
+
+	int_status = get_int_status();
+
+	/* if int_status == 0, then the interrupt has already been cleared */
+	if (int_status) {
+		irq = ls1bit32(int_status);
+
+		do_IRQ(irq);
+	}
+}
+
+void __init arch_init_irq(void)
+{
+	int i;
+
+	switch (mips_machtype) {
+	case MACH_LASAT_100:
+		lasat_int_status = (void *)LASAT_INT_STATUS_REG_100;
+		lasat_int_mask = (void *)LASAT_INT_MASK_REG_100;
+		lasat_int_mask_shift = LASATINT_MASK_SHIFT_100;
+		get_int_status = get_int_status_100;
+		*lasat_int_mask = 0;
+		break;
+	case MACH_LASAT_200:
+		lasat_int_status = (void *)LASAT_INT_STATUS_REG_200;
+		lasat_int_mask = (void *)LASAT_INT_MASK_REG_200;
+		lasat_int_mask_shift = LASATINT_MASK_SHIFT_200;
+		get_int_status = get_int_status_200;
+		*lasat_int_mask &= 0xffff;
+		break;
+	default:
+		panic("arch_init_irq: mips_machtype incorrect");
+	}
+
+	for (i = 0; i <= LASATINT_END; i++)
+		set_irq_chip_and_handler(i, &lasat_irq_type, handle_level_irq);
+}