ARM: msm: Divorce msm_timer from local timer API

Separate the msm_timer from the local timer API. This will allow
us to remove ARM local timer support in the near future and gets
us closer to moving this driver to drivers/clocksource.

Acked-by: David Brown <davidb@codeaurora.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Daniel Walker <dwalker@fifo99.com>
Cc: Bryan Huntsman <bryanh@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

1 files changed, 70 insertions, 56 deletions

diff --git a/arch/arm/mach-msm/timer.c b/arch/arm/mach-msm/timer.c
index b6418fd5fe0d..dacdcfdbc342 100644
--- a/arch/arm/mach-msm/timer.c
+++ b/arch/arm/mach-msm/timer.c
@@ -16,6 +16,7 @@
 
 #include <linux/clocksource.h>
 #include <linux/clockchips.h>
+#include <linux/cpu.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
@@ -26,7 +27,6 @@
 #include <linux/sched_clock.h>
 
 #include <asm/mach/time.h>
-#include <asm/localtimer.h>
 
 #include "common.h"
 
@@ -49,7 +49,7 @@ static void __iomem *sts_base;
 
 static irqreturn_t msm_timer_interrupt(int irq, void *dev_id)
 {
-        struct clock_event_device *evt = *(struct clock_event_device **)dev_id;
+        struct clock_event_device *evt = dev_id;
         /* Stop the timer tick */
         if (evt->mode == CLOCK_EVT_MODE_ONESHOT) {
                 u32 ctrl = readl_relaxed(event_base + TIMER_ENABLE);
@@ -101,18 +101,7 @@ static void msm_timer_set_mode(enum clock_event_mode mode,
         writel_relaxed(ctrl, event_base + TIMER_ENABLE);
 }
 
-static struct clock_event_device msm_clockevent = {
-        .name           = "gp_timer",
-        .features       = CLOCK_EVT_FEAT_ONESHOT,
-        .rating         = 200,
-        .set_next_event = msm_timer_set_next_event,
-        .set_mode       = msm_timer_set_mode,
-};
-
-static union {
-        struct clock_event_device *evt;
-        struct clock_event_device * __percpu *percpu_evt;
-} msm_evt;
+static struct clock_event_device __percpu *msm_evt;
 
 static void __iomem *source_base;
 
@@ -138,37 +127,65 @@ static struct clocksource msm_clocksource = {
         .flags  = CLOCK_SOURCE_IS_CONTINUOUS,
 };
 
-#ifdef CONFIG_LOCAL_TIMERS
+static int msm_timer_irq;
+static int msm_timer_has_ppi;
+
 static int __cpuinit msm_local_timer_setup(struct clock_event_device *evt)
 {
-        /* Use existing clock_event for cpu 0 */
-        if (!smp_processor_id())
-                return 0;
-
-        evt->irq = msm_clockevent.irq;
-        evt->name = "local_timer";
-        evt->features = msm_clockevent.features;
-        evt->rating = msm_clockevent.rating;
+        int cpu = smp_processor_id();
+        int err;
+
+        evt->irq = msm_timer_irq;
+        evt->name = "msm_timer";
+        evt->features = CLOCK_EVT_FEAT_ONESHOT;
+        evt->rating = 200;
         evt->set_mode = msm_timer_set_mode;
         evt->set_next_event = msm_timer_set_next_event;
+        evt->cpumask = cpumask_of(cpu);
+
+        clockevents_config_and_register(evt, GPT_HZ, 4, 0xffffffff);
+
+        if (msm_timer_has_ppi) {
+                enable_percpu_irq(evt->irq, IRQ_TYPE_EDGE_RISING);
+        } else {
+                err = request_irq(evt->irq, msm_timer_interrupt,
+                                IRQF_TIMER | IRQF_NOBALANCING |
+                                IRQF_TRIGGER_RISING, "gp_timer", evt);
+                if (err)
+                        pr_err("request_irq failed\n");
+        }
 
-        *__this_cpu_ptr(msm_evt.percpu_evt) = evt;
-        clockevents_config_and_register(evt, GPT_HZ, 4, 0xf0000000);
-        enable_percpu_irq(evt->irq, IRQ_TYPE_EDGE_RISING);
         return 0;
 }
 
-static void msm_local_timer_stop(struct clock_event_device *evt)
+static void __cpuinit msm_local_timer_stop(struct clock_event_device *evt)
 {
         evt->set_mode(CLOCK_EVT_MODE_UNUSED, evt);
         disable_percpu_irq(evt->irq);
 }
 
-static struct local_timer_ops msm_local_timer_ops __cpuinitdata = {
-        .setup  = msm_local_timer_setup,
-        .stop   = msm_local_timer_stop,
+static int __cpuinit msm_timer_cpu_notify(struct notifier_block *self,
+                                           unsigned long action, void *hcpu)
+{
+        /*
+         * Grab cpu pointer in each case to avoid spurious
+         * preemptible warnings
+         */
+        switch (action & ~CPU_TASKS_FROZEN) {
+        case CPU_STARTING:
+                msm_local_timer_setup(this_cpu_ptr(msm_evt));
+                break;
+        case CPU_DYING:
+                msm_local_timer_stop(this_cpu_ptr(msm_evt));
+                break;
+        }
+
+        return NOTIFY_OK;
+}
+
+static struct notifier_block msm_timer_cpu_nb __cpuinitdata = {
+        .notifier_call = msm_timer_cpu_notify,
 };
-#endif /* CONFIG_LOCAL_TIMERS */
 
 static notrace u32 msm_sched_clock_read(void)
 {
@@ -178,38 +195,35 @@ static notrace u32 msm_sched_clock_read(void)
 static void __init msm_timer_init(u32 dgt_hz, int sched_bits, int irq,
                                   bool percpu)
 {
-        struct clock_event_device *ce = &msm_clockevent;
         struct clocksource *cs = &msm_clocksource;
-        int res;
+        int res = 0;
+
+        msm_timer_irq = irq;
+        msm_timer_has_ppi = percpu;
+
+        msm_evt = alloc_percpu(struct clock_event_device);
+        if (!msm_evt) {
+                pr_err("memory allocation failed for clockevents\n");
+                goto err;
+        }
 
-        ce->cpumask = cpumask_of(0);
-        ce->irq = irq;
+        if (percpu)
+                res = request_percpu_irq(irq, msm_timer_interrupt,
+                                         "gp_timer", msm_evt);
 
-        clockevents_config_and_register(ce, GPT_HZ, 4, 0xffffffff);
-        if (percpu) {
-                msm_evt.percpu_evt = alloc_percpu(struct clock_event_device *);
-                if (!msm_evt.percpu_evt) {
-                        pr_err("memory allocation failed for %s\n", ce->name);
+        if (res) {
+                pr_err("request_percpu_irq failed\n");
+        } else {
+                res = register_cpu_notifier(&msm_timer_cpu_nb);
+                if (res) {
+                        free_percpu_irq(irq, msm_evt);
                         goto err;
                 }
-                *__this_cpu_ptr(msm_evt.percpu_evt) = ce;
-                res = request_percpu_irq(ce->irq, msm_timer_interrupt,
-                                         ce->name, msm_evt.percpu_evt);
-                if (!res) {
-                        enable_percpu_irq(ce->irq, IRQ_TYPE_EDGE_RISING);
-#ifdef CONFIG_LOCAL_TIMERS
-                        local_timer_register(&msm_local_timer_ops);
-#endif
-                }
-        } else {
-                msm_evt.evt = ce;
-                res = request_irq(ce->irq, msm_timer_interrupt,
-                                  IRQF_TIMER | IRQF_NOBALANCING |
-                                  IRQF_TRIGGER_RISING, ce->name, &msm_evt.evt);
+
+                /* Immediately configure the timer on the boot CPU */
+                msm_local_timer_setup(__this_cpu_ptr(msm_evt));
         }
 
-        if (res)
-                pr_err("request_irq failed for %s\n", ce->name);
 err:
         writel_relaxed(TIMER_ENABLE_EN, source_base + TIMER_ENABLE);
         res = clocksource_register_hz(cs, dgt_hz);