ARM: smp_twd: add runtime registration support

Add support for the new registration interface to smp_twd.
Platforms can populate a struct twd_local_timer with MMIO
and IRQ resources, and then call twd_local_timer_register()
to have the timer registered with the core.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

diff --git a/arch/arm/include/asm/smp_twd.h b/arch/arm/include/asm/smp_twd.h
index bf8449d..16c89b7 100644 (file)
--- a/arch/arm/include/asm/smp_twd.h
+++ b/arch/arm/include/asm/smp_twd.h
@@ -18,10 +18,26 @@
 #define TWD_TIMER_CONTROL_PERIODIC     (1 << 1)
 #define TWD_TIMER_CONTROL_IT_ENABLE    (1 << 2)
 
+#include <linux/ioport.h>
+
 struct clock_event_device;
 
 extern void __iomem *twd_base;
 
-void twd_timer_setup(struct clock_event_device *);
+int twd_timer_setup(struct clock_event_device *);
+
+struct twd_local_timer {
+       struct resource res[2];
+};
+
+#define DEFINE_TWD_LOCAL_TIMER(name,base,irq)  \
+struct twd_local_timer name __initdata = {     \
+       .res    = {                             \
+               DEFINE_RES_MEM(base, 0x10),     \
+               DEFINE_RES_IRQ(irq),            \
+       },                                      \
+};
+
+int twd_local_timer_register(struct twd_local_timer *);
 
 #endif

diff --git a/arch/arm/kernel/smp_twd.c b/arch/arm/kernel/smp_twd.c
index b39916a..18c55f1 100644 (file)
--- a/arch/arm/kernel/smp_twd.c
+++ b/arch/arm/kernel/smp_twd.c
@@ -32,6 +32,7 @@ static struct clk *twd_clk;
 static unsigned long twd_timer_rate;
 
 static struct clock_event_device __percpu **twd_evt;
+static int twd_ppi;
 
 static void twd_set_mode(enum clock_event_mode mode,
                        struct clock_event_device *clk)
@@ -227,7 +228,7 @@ static struct clk *twd_get_clock(void)
 /*
  * Setup the local clock events for a CPU.
  */
-void __cpuinit twd_timer_setup(struct clock_event_device *clk)
+int __cpuinit twd_timer_setup(struct clock_event_device *clk)
 {
        struct clock_event_device **this_cpu_clk;
 
@@ -237,7 +238,7 @@ void __cpuinit twd_timer_setup(struct clock_event_device *clk)
                twd_evt = alloc_percpu(struct clock_event_device *);
                if (!twd_evt) {
                        pr_err("twd: can't allocate memory\n");
-                       return;
+                       return -ENOMEM;
                }
 
                err = request_percpu_irq(clk->irq, twd_handler,
@@ -245,7 +246,7 @@ void __cpuinit twd_timer_setup(struct clock_event_device *clk)
                if (err) {
                        pr_err("twd: can't register interrupt %d (%d)\n",
                               clk->irq, err);
-                       return;
+                       return err;
                }
        }
 
@@ -265,6 +266,8 @@ void __cpuinit twd_timer_setup(struct clock_event_device *clk)
        clk->rating = 350;
        clk->set_mode = twd_set_mode;
        clk->set_next_event = twd_set_next_event;
+       if (!clk->irq)
+               clk->irq = twd_ppi;
 
        this_cpu_clk = __this_cpu_ptr(twd_evt);
        *this_cpu_clk = clk;
@@ -272,4 +275,46 @@ void __cpuinit twd_timer_setup(struct clock_event_device *clk)
        clockevents_config_and_register(clk, twd_timer_rate,
                                        0xf, 0xffffffff);
        enable_percpu_irq(clk->irq, 0);
+
+       return 0;
+}
+
+static struct local_timer_ops twd_lt_ops __cpuinitdata = {
+       .setup  = twd_timer_setup,
+       .stop   = twd_timer_stop,
+};
+
+int __init twd_local_timer_register(struct twd_local_timer *tlt)
+{
+       int err;
+
+       if (twd_base || twd_evt)
+               return -EBUSY;
+
+       twd_ppi = tlt->res[1].start;
+
+       twd_evt = alloc_percpu(struct clock_event_device *);
+       twd_base = ioremap(tlt->res[0].start, resource_size(&tlt->res[0]));
+       if (!twd_base || !twd_evt) {
+               err = -ENOMEM;
+               goto out;
+       }
+
+       err = request_percpu_irq(twd_ppi, twd_handler, "twd", twd_evt);
+       if (err) {
+               pr_err("twd: can't register interrupt %d (%d)\n", twd_ppi, err);
+               goto out;
+       }
+
+       err = local_timer_register(&twd_lt_ops);
+       if (err)
+               goto out;
+
+       return 0;
+
+out:
+       iounmap(twd_base);
+       free_percpu(twd_evt);
+       twd_base = twd_evt = NULL;
+       return err;
 }