irqchip: mips-gic: Export function to read counter width

Export the function gic_get_count_width to read the width of
the GIC global counter from GIC_SH_CONFIG.  Update the GIC
clocksource driver to use this new function.

Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Qais Yousef <qais.yousef@imgtec.com>
Cc: John Crispin <blogic@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8124/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c
index e49a39a8c853..b5fad6377736 100644
--- a/drivers/irqchip/irq-mips-gic.c
+++ b/drivers/irqchip/irq-mips-gic.c
@@ -63,6 +63,17 @@ cycle_t gic_read_count(void)
         return (((cycle_t) hi) << 32) + lo;
 }
 
+unsigned int gic_get_count_width(void)
+{
+        unsigned int bits, config;
+
+        GICREAD(GIC_REG(SHARED, GIC_SH_CONFIG), config);
+        bits = 32 + 4 * ((config & GIC_SH_CONFIG_COUNTBITS_MSK) >>
+                         GIC_SH_CONFIG_COUNTBITS_SHF);
+
+        return bits;
+}
+
 void gic_write_compare(cycle_t cnt)
 {
         GICWRITE(GIC_REG(VPE_LOCAL, GIC_VPE_COMPARE_HI),