ARM: convert arm/arm64 arch timer to use CLKSRC_OF init

This converts arm and arm64 to use CLKSRC_OF DT based initialization for
the arch timer. A new function arch_timer_arch_init is added to allow for
arch specific setup.

This has a side effect of enabling sched_clock on omap5 and exynos5. There
should not be any reason not to use the arch timers for sched_clock.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Simon Horman <horms@verge.net.au>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-samsung-soc@vger.kernel.org
Cc: linux-omap@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>

2 files changed, 10 insertions, 14 deletions

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index e507ab7df60b..d98e7e1ee594 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -62,6 +62,7 @@ config CLKSRC_DBX500_PRCMU_SCHED_CLOCK
 
 config ARM_ARCH_TIMER
         bool
+        select CLKSRC_OF if OF
 
 config CLKSRC_METAG_GENERIC
         def_bool y if METAG
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index d7ad425ab9b3..122ff05628b5 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -337,22 +337,14 @@ out:
         return err;
 }
 
-static const struct of_device_id arch_timer_of_match[] __initconst = {
-        { .compatible   = "arm,armv7-timer",    },
-        { .compatible   = "arm,armv8-timer",    },
-        {},
-};
-
-int __init arch_timer_init(void)
+static void __init arch_timer_init(struct device_node *np)
 {
-        struct device_node *np;
         u32 freq;
         int i;
 
-        np = of_find_matching_node(NULL, arch_timer_of_match);
-        if (!np) {
-                pr_err("arch_timer: can't find DT node\n");
-                return -ENODEV;
+        if (arch_timer_get_rate()) {
+                pr_warn("arch_timer: multiple nodes in dt, skipping\n");
+                return;
         }
 
         /* Try to determine the frequency from the device tree or CNTFRQ */
@@ -378,7 +370,7 @@ int __init arch_timer_init(void)
                 if (!arch_timer_ppi[PHYS_SECURE_PPI] ||
                     !arch_timer_ppi[PHYS_NONSECURE_PPI]) {
                         pr_warn("arch_timer: No interrupt available, giving up\n");
-                        return -EINVAL;
+                        return;
                 }
         }
 
@@ -387,5 +379,8 @@ int __init arch_timer_init(void)
         else
                 arch_timer_read_counter = arch_counter_get_cntpct;
 
-        return arch_timer_register();
+        arch_timer_register();
+        arch_timer_arch_init();
 }
+CLOCKSOURCE_OF_DECLARE(armv7_arch_timer, "arm,armv7-timer", arch_timer_init);
+CLOCKSOURCE_OF_DECLARE(armv8_arch_timer, "arm,armv8-timer", arch_timer_init);