1 files changed, 136 insertions, 0 deletions
diff --git a/arch/mips/sibyte/sb1250/time.c b/arch/mips/sibyte/sb1250/time.c
new file mode 100644
index 0000000..8b4c848
--- /dev/null
+++ b/arch/mips/sibyte/sb1250/time.c
@@ -0,0 +1,136 @@
+/*
+ * Copyright (C) 2000, 2001 Broadcom Corporation
+ *
+ * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+/*
+ * These are routines to set up and handle interrupts from the
+ * sb1250 general purpose timer 0.  We're using the timer as a
+ * system clock, so we set it up to run at 100 Hz.  On every
+ * interrupt, we update our idea of what the time of day is,
+ * then call do_timer() in the architecture-independent kernel
+ * code to do general bookkeeping (e.g. update jiffies, run
+ * bottom halves, etc.)
+ */
+#include <linux/config.h>
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/kernel_stat.h>
+
+#include <asm/irq.h>
+#include <asm/ptrace.h>
+#include <asm/addrspace.h>
+#include <asm/time.h>
+#include <asm/io.h>
+
+#include <asm/sibyte/sb1250.h>
+#include <asm/sibyte/sb1250_regs.h>
+#include <asm/sibyte/sb1250_int.h>
+#include <asm/sibyte/sb1250_scd.h>
+
+
+#define IMR_IP2_VAL	K_INT_MAP_I0
+#define IMR_IP3_VAL	K_INT_MAP_I1
+#define IMR_IP4_VAL	K_INT_MAP_I2
+
+extern int sb1250_steal_irq(int irq);
+
+void sb1250_time_init(void)
+{
+	int cpu = smp_processor_id();
+	int irq = K_INT_TIMER_0+cpu;
+
+	/* Only have 4 general purpose timers */
+	if (cpu > 3) {
+		BUG();
+	}
+
+	if (!cpu) {
+		/* Use our own gettimeoffset() routine */
+		do_gettimeoffset = sb1250_gettimeoffset;
+	}
+
+	sb1250_mask_irq(cpu, irq);
+
+	/* Map the timer interrupt to ip[4] of this cpu */
+	bus_writeq(IMR_IP4_VAL,
+		   IOADDR(A_IMR_REGISTER(cpu, R_IMR_INTERRUPT_MAP_BASE) +
+			  (irq << 3)));
+
+	/* the general purpose timer ticks at 1 Mhz independent if the rest of the system */
+	/* Disable the timer and set up the count */
+	bus_writeq(0, IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)));
+#ifdef CONFIG_SIMULATION
+	bus_writeq(50000 / HZ,
+		   IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT)));
+#else
+	bus_writeq(1000000/HZ,
+		   IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT)));
+#endif
+
+	/* Set the timer running */
+	bus_writeq(M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS,
+		   IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)));
+
+	sb1250_unmask_irq(cpu, irq);
+	sb1250_steal_irq(irq);
+	/*
+	 * This interrupt is "special" in that it doesn't use the request_irq
+	 * way to hook the irq line.  The timer interrupt is initialized early
+	 * enough to make this a major pain, and it's also firing enough to
+	 * warrant a bit of special case code.  sb1250_timer_interrupt is
+	 * called directly from irq_handler.S when IP[4] is set during an
+	 * interrupt
+	 */
+}
+
+void sb1250_timer_interrupt(struct pt_regs *regs)
+{
+	extern asmlinkage void ll_local_timer_interrupt(int irq, struct pt_regs *regs);
+	int cpu = smp_processor_id();
+	int irq = K_INT_TIMER_0 + cpu;
+
+	/* Reset the timer */
+	__bus_writeq(M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS,
+		     IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)));
+
+	/*
+	 * CPU 0 handles the global timer interrupt job
+	 */
+	if (cpu == 0) {
+		ll_timer_interrupt(irq, regs);
+	}
+
+	/*
+	 * every CPU should do profiling and process accouting
+	 */
+	ll_local_timer_interrupt(irq, regs);
+}
+
+/*
+ * We use our own do_gettimeoffset() instead of the generic one,
+ * because the generic one does not work for SMP case.
+ * In addition, since we use general timer 0 for system time,
+ * we can get accurate intra-jiffy offset without calibration.
+ */
+unsigned long sb1250_gettimeoffset(void)
+{
+	unsigned long count =
+		bus_readq(IOADDR(A_SCD_TIMER_REGISTER(0, R_SCD_TIMER_CNT)));
+
+	return 1000000/HZ - count;
+ }