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>

19 files changed, 29 insertions, 87 deletions

diff --git a/arch/arm/include/asm/arch_timer.h b/arch/arm/include/asm/arch_timer.h
index 7ade91d8cc6f..7c1bfc0aea0c 100644
--- a/arch/arm/include/asm/arch_timer.h
+++ b/arch/arm/include/asm/arch_timer.h
@@ -10,8 +10,7 @@
 #include <clocksource/arm_arch_timer.h>
 
 #ifdef CONFIG_ARM_ARCH_TIMER
-int arch_timer_of_register(void);
-int arch_timer_sched_clock_init(void);
+int arch_timer_arch_init(void);
 
 /*
  * These register accessors are marked inline so the compiler can
@@ -110,16 +109,6 @@ static inline void __cpuinit arch_counter_set_user_access(void)
 
         asm volatile("mcr p15, 0, %0, c14, c1, 0" : : "r" (cntkctl));
 }
-#else
-static inline int arch_timer_of_register(void)
-{
-        return -ENXIO;
-}
-
-static inline int arch_timer_sched_clock_init(void)
-{
-        return -ENXIO;
-}
 #endif
 
 #endif
diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c
index 80c458fc4a30..59dcdced6e30 100644
--- a/arch/arm/kernel/arch_timer.c
+++ b/arch/arm/kernel/arch_timer.c
@@ -39,26 +39,15 @@ static void __init arch_timer_delay_timer_register(void)
         register_current_timer_delay(&arch_delay_timer);
 }
 
-int __init arch_timer_of_register(void)
-{
-        int ret;
-
-        ret = arch_timer_init();
-        if (ret)
-                return ret;
-
-        arch_timer_delay_timer_register();
-
-        return 0;
-}
-
-int __init arch_timer_sched_clock_init(void)
+int __init arch_timer_arch_init(void)
 {
         u32 arch_timer_rate = arch_timer_get_rate();
 
         if (arch_timer_rate == 0)
                 return -ENXIO;
 
+        arch_timer_delay_timer_register();
+
         /* Cache the sched_clock multiplier to save a divide in the hot path. */
         sched_clock_mult = NSEC_PER_SEC / arch_timer_rate;
         sched_clock_func = arch_timer_sched_clock;
diff --git a/arch/arm/mach-exynos/mach-exynos5-dt.c b/arch/arm/mach-exynos/mach-exynos5-dt.c
index acaeb14db54b..4d97b4311084 100644
--- a/arch/arm/mach-exynos/mach-exynos5-dt.c
+++ b/arch/arm/mach-exynos/mach-exynos5-dt.c
@@ -216,7 +216,6 @@ DT_MACHINE_START(EXYNOS5_DT, "SAMSUNG EXYNOS5 (Flattened Device Tree)")
         .map_io         = exynos5_dt_map_io,
         .init_machine   = exynos5_dt_machine_init,
         .init_late      = exynos_init_late,
-        .init_time      = exynos4_timer_init,
         .dt_compat      = exynos5_dt_compat,
         .restart        = exynos5_restart,
         .reserve        = exynos5_reserve,
diff --git a/arch/arm/mach-exynos/mct.c b/arch/arm/mach-exynos/mct.c
index c9d6650f9b5d..04aff6a61e8d 100644
--- a/arch/arm/mach-exynos/mct.c
+++ b/arch/arm/mach-exynos/mct.c
@@ -21,7 +21,6 @@
 #include <linux/percpu.h>
 #include <linux/of.h>
 
-#include <asm/arch_timer.h>
 #include <asm/localtimer.h>
 
 #include <plat/cpu.h>
@@ -469,11 +468,6 @@ static void __init exynos4_timer_resources(void)
 
 void __init exynos4_timer_init(void)
 {
-        if (soc_is_exynos5440()) {
-                arch_timer_of_register();
-                return;
-        }
-
         if ((soc_is_exynos4210()) || (soc_is_exynos5250()))
                 mct_int_type = MCT_INT_SPI;
         else
diff --git a/arch/arm/mach-highbank/highbank.c b/arch/arm/mach-highbank/highbank.c
index 76c1170b3528..758150eb9975 100644
--- a/arch/arm/mach-highbank/highbank.c
+++ b/arch/arm/mach-highbank/highbank.c
@@ -15,6 +15,7 @@
  */
 #include <linux/clk.h>
 #include <linux/clkdev.h>
+#include <linux/clocksource.h>
 #include <linux/dma-mapping.h>
 #include <linux/io.h>
 #include <linux/irq.h>
@@ -28,7 +29,6 @@
 #include <linux/amba/bus.h>
 #include <linux/clk-provider.h>
 
-#include <asm/arch_timer.h>
 #include <asm/cacheflush.h>
 #include <asm/cputype.h>
 #include <asm/smp_plat.h>
@@ -118,9 +118,6 @@ static void __init highbank_timer_init(void)
         sp804_clocksource_and_sched_clock_init(timer_base + 0x20, "timer1");
         sp804_clockevents_init(timer_base, irq, "timer0");
 
-        arch_timer_of_register();
-        arch_timer_sched_clock_init();
-
         clocksource_of_init();
 }
 
diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c
index 4fd80257c73e..7dd6453a213e 100644
--- a/arch/arm/mach-omap2/timer.c
+++ b/arch/arm/mach-omap2/timer.c
@@ -46,7 +46,6 @@
 #include <asm/smp_twd.h>
 #include <asm/sched_clock.h>
 
-#include <asm/arch_timer.h>
 #include "omap_hwmod.h"
 #include "omap_device.h"
 #include <plat/counter-32k.h>
@@ -624,9 +623,7 @@ void __init omap5_realtime_timer_init(void)
         omap5_sync32k_timer_init();
         realtime_counter_init();
 
-        err = arch_timer_of_register();
-        if (err)
-                pr_err("%s: arch_timer_register failed %d\n", __func__, err);
+        clocksource_of_init();
 }
 #endif /* CONFIG_SOC_OMAP5 */
 
diff --git a/arch/arm/mach-shmobile/board-kzm9d.c b/arch/arm/mach-shmobile/board-kzm9d.c
index c254782aa727..c016ccd92433 100644
--- a/arch/arm/mach-shmobile/board-kzm9d.c
+++ b/arch/arm/mach-shmobile/board-kzm9d.c
@@ -90,6 +90,5 @@ DT_MACHINE_START(KZM9D_DT, "kzm9d")
         .init_irq       = emev2_init_irq,
         .init_machine   = kzm9d_add_standard_devices,
         .init_late      = shmobile_init_late,
-        .init_time      = shmobile_timer_init,
         .dt_compat      = kzm9d_boards_compat_dt,
 MACHINE_END
diff --git a/arch/arm/mach-shmobile/setup-emev2.c b/arch/arm/mach-shmobile/setup-emev2.c
index 47662a581c0a..4e38a66508a4 100644
--- a/arch/arm/mach-shmobile/setup-emev2.c
+++ b/arch/arm/mach-shmobile/setup-emev2.c
@@ -456,7 +456,6 @@ DT_MACHINE_START(EMEV2_DT, "Generic Emma Mobile EV2 (Flattened Device Tree)")
         .nr_irqs        = NR_IRQS_LEGACY,
         .init_irq       = irqchip_init,
         .init_machine   = emev2_add_standard_devices_dt,
-        .init_time      = shmobile_timer_init,
         .dt_compat      = emev2_boards_compat_dt,
 MACHINE_END
 
diff --git a/arch/arm/mach-shmobile/setup-r8a7740.c b/arch/arm/mach-shmobile/setup-r8a7740.c
index 8b85d4d8fab6..104b474a2ccf 100644
--- a/arch/arm/mach-shmobile/setup-r8a7740.c
+++ b/arch/arm/mach-shmobile/setup-r8a7740.c
@@ -906,7 +906,6 @@ DT_MACHINE_START(R8A7740_DT, "Generic R8A7740 (Flattened Device Tree)")
         .init_irq       = r8a7740_init_irq,
         .handle_irq     = shmobile_handle_irq_intc,
         .init_machine   = r8a7740_add_standard_devices_dt,
-        .init_time      = shmobile_timer_init,
         .dt_compat      = r8a7740_boards_compat_dt,
 MACHINE_END
 
diff --git a/arch/arm/mach-shmobile/setup-sh7372.c b/arch/arm/mach-shmobile/setup-sh7372.c
index 59c7146bf66f..5502d624aca6 100644
--- a/arch/arm/mach-shmobile/setup-sh7372.c
+++ b/arch/arm/mach-shmobile/setup-sh7372.c
@@ -1175,7 +1175,6 @@ DT_MACHINE_START(SH7372_DT, "Generic SH7372 (Flattened Device Tree)")
         .init_irq       = sh7372_init_irq,
         .handle_irq     = shmobile_handle_irq_intc,
         .init_machine   = sh7372_add_standard_devices_dt,
-        .init_time      = shmobile_timer_init,
         .dt_compat      = sh7372_boards_compat_dt,
 MACHINE_END
 
diff --git a/arch/arm/mach-shmobile/setup-sh73a0.c b/arch/arm/mach-shmobile/setup-sh73a0.c
index bdab575f88bc..ea66316f0ac9 100644
--- a/arch/arm/mach-shmobile/setup-sh73a0.c
+++ b/arch/arm/mach-shmobile/setup-sh73a0.c
@@ -923,7 +923,6 @@ DT_MACHINE_START(SH73A0_DT, "Generic SH73A0 (Flattened Device Tree)")
         .nr_irqs        = NR_IRQS_LEGACY,
         .init_irq       = sh73a0_init_irq_dt,
         .init_machine   = sh73a0_add_standard_devices_dt,
-        .init_time      = shmobile_timer_init,
         .dt_compat      = sh73a0_boards_compat_dt,
 MACHINE_END
 #endif /* CONFIG_USE_OF */
diff --git a/arch/arm/mach-shmobile/timer.c b/arch/arm/mach-shmobile/timer.c
index 3d16d4dff01b..f321dbeb2379 100644
--- a/arch/arm/mach-shmobile/timer.c
+++ b/arch/arm/mach-shmobile/timer.c
@@ -19,10 +19,8 @@
  *
  */
 #include <linux/platform_device.h>
+#include <linux/clocksource.h>
 #include <linux/delay.h>
-#include <asm/arch_timer.h>
-#include <asm/mach/time.h>
-#include <asm/smp_twd.h>
 
 void __init shmobile_setup_delay(unsigned int max_cpu_core_mhz,
                                  unsigned int mult, unsigned int div)
@@ -63,6 +61,5 @@ void __init shmobile_earlytimer_init(void)
 
 void __init shmobile_timer_init(void)
 {
-        arch_timer_of_register();
-        arch_timer_sched_clock_init();
+        clocksource_of_init();
 }
diff --git a/arch/arm/mach-vexpress/v2m.c b/arch/arm/mach-vexpress/v2m.c
index d0ad78998cb6..621571781b20 100644
--- a/arch/arm/mach-vexpress/v2m.c
+++ b/arch/arm/mach-vexpress/v2m.c
@@ -1,6 +1,7 @@
 /*
  * Versatile Express V2M Motherboard Support
  */
+#include <linux/clocksource.h>
 #include <linux/device.h>
 #include <linux/amba/bus.h>
 #include <linux/amba/mmci.h>
@@ -23,7 +24,6 @@
 #include <linux/regulator/machine.h>
 #include <linux/vexpress.h>
 
-#include <asm/arch_timer.h>
 #include <asm/mach-types.h>
 #include <asm/sizes.h>
 #include <asm/mach/arch.h>
@@ -446,10 +446,7 @@ static void __init v2m_dt_timer_init(void)
                                 irq_of_parse_and_map(node, 0));
         }
 
-        arch_timer_of_register();
-
-        if (arch_timer_sched_clock_init() != 0)
-                versatile_sched_clock_init(vexpress_get_24mhz_clock_base(),
+        versatile_sched_clock_init(vexpress_get_24mhz_clock_base(),
                                 24000000);
 }
 
diff --git a/arch/arm/mach-virt/virt.c b/arch/arm/mach-virt/virt.c
index 31666f6b4373..adc0945255ae 100644
--- a/arch/arm/mach-virt/virt.c
+++ b/arch/arm/mach-virt/virt.c
@@ -23,21 +23,13 @@
 #include <linux/of_platform.h>
 #include <linux/smp.h>
 
-#include <asm/arch_timer.h>
 #include <asm/mach/arch.h>
-#include <asm/mach/time.h>
 
 static void __init virt_init(void)
 {
         of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
 }
 
-static void __init virt_timer_init(void)
-{
-        WARN_ON(arch_timer_of_register() != 0);
-        WARN_ON(arch_timer_sched_clock_init() != 0);
-}
-
 static const char *virt_dt_match[] = {
         "linux,dummy-virt",
         NULL
@@ -47,7 +39,6 @@ extern struct smp_operations virt_smp_ops;
 
 DT_MACHINE_START(VIRT, "Dummy Virtual Machine")
         .init_irq       = irqchip_init,
-        .init_time      = virt_timer_init,
         .init_machine   = virt_init,
         .smp            = smp_ops(virt_smp_ops),
         .dt_compat      = virt_dt_match,
diff --git a/arch/arm64/include/asm/arch_timer.h b/arch/arm64/include/asm/arch_timer.h
index 91e2a6a6fcd4..bf6ab242f047 100644
--- a/arch/arm64/include/asm/arch_timer.h
+++ b/arch/arm64/include/asm/arch_timer.h
@@ -130,4 +130,9 @@ static inline u64 arch_counter_get_cntvct(void)
         return cval;
 }
 
+static inline int arch_timer_arch_init(void)
+{
+        return 0;
+}
+
 #endif
diff --git a/arch/arm64/kernel/time.c b/arch/arm64/kernel/time.c
index b0ef18d14c3b..a551f88ae2c1 100644
--- a/arch/arm64/kernel/time.c
+++ b/arch/arm64/kernel/time.c
@@ -32,6 +32,7 @@
 #include <linux/timer.h>
 #include <linux/irq.h>
 #include <linux/delay.h>
+#include <linux/clocksource.h>
 
 #include <clocksource/arm_arch_timer.h>
 
@@ -77,10 +78,11 @@ void __init time_init(void)
 {
         u32 arch_timer_rate;
 
-        if (arch_timer_init())
-                panic("Unable to initialise architected timer.\n");
+        clocksource_of_init();
 
         arch_timer_rate = arch_timer_get_rate();
+        if (!arch_timer_rate)
+                panic("Unable to initialise architected timer.\n");
 
         /* Cache the sched_clock multiplier to save a divide in the hot path. */
         sched_clock_mult = NSEC_PER_SEC / arch_timer_rate;
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);
diff --git a/include/clocksource/arm_arch_timer.h b/include/clocksource/arm_arch_timer.h
index 2603267b1a29..e6c9c4cc9b23 100644
--- a/include/clocksource/arm_arch_timer.h
+++ b/include/clocksource/arm_arch_timer.h
@@ -31,18 +31,12 @@
 
 #ifdef CONFIG_ARM_ARCH_TIMER
 
-extern int arch_timer_init(void);
 extern u32 arch_timer_get_rate(void);
 extern u64 (*arch_timer_read_counter)(void);
 extern struct timecounter *arch_timer_get_timecounter(void);
 
 #else
 
-static inline int arch_timer_init(void)
-{
-        return -ENXIO;
-}
-
 static inline u32 arch_timer_get_rate(void)
 {
         return 0;