Merge branches 'cache-l2x0', 'fixes', 'hdrs', 'misc', 'mmci', 'vic' and 'warnings...

[GitHub/LineageOS/android_kernel_samsung_universal7580.git] / arch / arm / kernel / smp_twd.c

diff --git a/arch/arm/kernel/smp_twd.c b/arch/arm/kernel/smp_twd.c
index e1f906989bb8161963d8a714073a8d84a8e2c2e6..ff07879ad95d467f5a2ac7ab4439a9c898c36bbb 100644 (file)
--- a/arch/arm/kernel/smp_twd.c
+++ b/arch/arm/kernel/smp_twd.c
@@ -31,6 +31,8 @@ static void __iomem *twd_base;
 
 static struct clk *twd_clk;
 static unsigned long twd_timer_rate;
+static bool common_setup_called;
+static DEFINE_PER_CPU(bool, percpu_setup_called);
 
 static struct clock_event_device __percpu **twd_evt;
 static int twd_ppi;
@@ -42,10 +44,10 @@ static void twd_set_mode(enum clock_event_mode mode,
 
        switch (mode) {
        case CLOCK_EVT_MODE_PERIODIC:
-               /* timer load already set up */
                ctrl = TWD_TIMER_CONTROL_ENABLE | TWD_TIMER_CONTROL_IT_ENABLE
                        | TWD_TIMER_CONTROL_PERIODIC;
-               __raw_writel(twd_timer_rate / HZ, twd_base + TWD_TIMER_LOAD);
+               __raw_writel(DIV_ROUND_CLOSEST(twd_timer_rate, HZ),
+                       twd_base + TWD_TIMER_LOAD);
                break;
        case CLOCK_EVT_MODE_ONESHOT:
                /* period set, and timer enabled in 'next_event' hook */
@@ -248,17 +250,9 @@ static struct clk *twd_get_clock(void)
                return clk;
        }
 
-       err = clk_prepare(clk);
+       err = clk_prepare_enable(clk);
        if (err) {
-               pr_err("smp_twd: clock failed to prepare: %d\n", err);
-               clk_put(clk);
-               return ERR_PTR(err);
-       }
-
-       err = clk_enable(clk);
-       if (err) {
-               pr_err("smp_twd: clock failed to enable: %d\n", err);
-               clk_unprepare(clk);
+               pr_err("smp_twd: clock failed to prepare+enable: %d\n", err);
                clk_put(clk);
                return ERR_PTR(err);
        }
@@ -272,15 +266,45 @@ static struct clk *twd_get_clock(void)
 static int __cpuinit twd_timer_setup(struct clock_event_device *clk)
 {
        struct clock_event_device **this_cpu_clk;
+       int cpu = smp_processor_id();
+
+       /*
+        * If the basic setup for this CPU has been done before don't
+        * bother with the below.
+        */
+       if (per_cpu(percpu_setup_called, cpu)) {
+               __raw_writel(0, twd_base + TWD_TIMER_CONTROL);
+               clockevents_register_device(*__this_cpu_ptr(twd_evt));
+               enable_percpu_irq(clk->irq, 0);
+               return 0;
+       }
+       per_cpu(percpu_setup_called, cpu) = true;
 
-       if (!twd_clk)
+       /*
+        * This stuff only need to be done once for the entire TWD cluster
+        * during the runtime of the system.
+        */
+       if (!common_setup_called) {
                twd_clk = twd_get_clock();
 
-       if (!IS_ERR_OR_NULL(twd_clk))
-               twd_timer_rate = clk_get_rate(twd_clk);
-       else
-               twd_calibrate_rate();
+               /*
+                * We use IS_ERR_OR_NULL() here, because if the clock stubs
+                * are active we will get a valid clk reference which is
+                * however NULL and will return the rate 0. In that case we
+                * need to calibrate the rate instead.
+                */
+               if (!IS_ERR_OR_NULL(twd_clk))
+                       twd_timer_rate = clk_get_rate(twd_clk);
+               else
+                       twd_calibrate_rate();
+
+               common_setup_called = true;
+       }
 
+       /*
+        * The following is done once per CPU the first time .setup() is
+        * called.
+        */
        __raw_writel(0, twd_base + TWD_TIMER_CONTROL);
 
        clk->name = "local_timer";