MIPS: Refactor GIC clocksource code.

Reorganize some of the GIC clocksource driver code. Below is a list of
the various changes.

  * No longer select CSRC_GIC by default for Malta platform.
  * Limit choice for either the GIC or R4K clocksource, not both.
  * Change location in Makefile.
  * Created new 'gic_read_count' function in common 'irq-gic.c' file.
  * Change 'git_hpt_read' function in 'csrc-gic.c' to use new function.
  * Surround GIC specific code in Malta platform code with #ifdef's.
  * Only initialize the GIC clocksource if it was selected. Original
    code called it unconditionally if a GIC was found.

Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/arch/mips/kernel/irq-gic.c b/arch/mips/kernel/irq-gic.c
index eaf7c1eb873e..6a476e1d41eb 100644
--- a/arch/mips/kernel/irq-gic.c
+++ b/arch/mips/kernel/irq-gic.c
@@ -10,6 +10,7 @@
 #include <linux/init.h>
 #include <linux/smp.h>
 #include <linux/irq.h>
+#include <linux/clocksource.h>
 
 #include <asm/io.h>
 #include <asm/gic.h>
@@ -32,6 +33,21 @@ static struct gic_pcpu_mask pcpu_masks[NR_CPUS];
 static struct gic_pending_regs pending_regs[NR_CPUS];
 static struct gic_intrmask_regs intrmask_regs[NR_CPUS];
 
+#ifdef CONFIG_CSRC_GIC
+cycle_t gic_read_count(void)
+{
+	unsigned int hi, hi2, lo;
+
+	do {
+		GICREAD(GIC_REG(SHARED, GIC_SH_COUNTER_63_32), hi);
+		GICREAD(GIC_REG(SHARED, GIC_SH_COUNTER_31_00), lo);
+		GICREAD(GIC_REG(SHARED, GIC_SH_COUNTER_63_32), hi2);
+	} while (hi2 != hi);
+
+	return (((cycle_t) hi) << 32) + lo;
+}
+#endif
+
 unsigned int gic_get_timer_pending(void)
 {
 	unsigned int vpe_pending;