clocksource/drivers/sun4i-timer: Only register a sched_clock on sun4i and sun5i

sun6i and newer have an arm arch timer which is a better
sched_clock source then the sun4i-timer, and sched_clock does
not have priorities, so do not register the sun4i-timer
sched_clock at all on sun6i and newer.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: ben.dooks@codethink.co.uk
Cc: digetx@gmail.com
Cc: laurent.pinchart+renesas@ideasonboard.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: viresh.kumar@linaro.org
Link: http://lkml.kernel.org/r/1427746633-9137-8-git-send-email-daniel.lezcano@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

drivers/clocksource/sun4i_timer.c

@@ -170,7 +170,15 @@ static void __init sun4i_timer_init(struct device_node *node)
 	       TIMER_CTL_CLK_SRC(TIMER_CTL_CLK_SRC_OSC24M),
 	       timer_base + TIMER_CTL_REG(1));
 
-	sched_clock_register(sun4i_timer_sched_read, 32, rate);
+	/*
+	 * sched_clock_register does not have priorities, and on sun6i and
+	 * later there is a better sched_clock registered by arm_arch_timer.c
+	 */
+	if (of_machine_is_compatible("allwinner,sun4i-a10") ||
+	    of_machine_is_compatible("allwinner,sun5i-a13") ||
+	    of_machine_is_compatible("allwinner,sun5i-a10s"))
+		sched_clock_register(sun4i_timer_sched_read, 32, rate);
+
 	clocksource_mmio_init(timer_base + TIMER_CNTVAL_REG(1), node->name,
 			      rate, 350, 32, clocksource_mmio_readl_down);