[PATCH v20 16/17] clocksource/drivers/arm_arch_timer: Add GTDT support for memory-mapped timer

[fu . wei]

From: Fu Wei <fu....@linaro.org>

The patch add memory-mapped timer register support by using the
information provided by the new GTDT driver of ACPI.

Signed-off-by: Fu Wei <fu....@linaro.org>
---
 drivers/clocksource/arm_arch_timer.c | 35 ++++++++++++++++++++++++++++++++---
 1 file changed, 32 insertions(+), 3 deletions(-)

diff --git a/drivers/clocksource/arm_arch_timer.c 
b/drivers/clocksource/arm_arch_timer.c
index 79dc004..7ca2da7 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -1077,10 +1077,36 @@ CLOCKSOURCE_OF_DECLARE(armv7_arch_timer_mem, 
"arm,armv7-timer-mem",
                       arch_timer_mem_of_init);
 
 #ifdef CONFIG_ACPI_GTDT
-/* Initialize per-processor generic timer */
+static int __init arch_timer_mem_acpi_init(int platform_timer_count)
+{
+       struct arch_timer_mem *timer_mem;
+       int timer_count, i, ret;
+
+       timer_mem = kcalloc(platform_timer_count, sizeof(*timer_mem),
+                           GFP_KERNEL);
+       if (!timer_mem)
+               return -ENOMEM;
+
+       ret = acpi_arch_timer_mem_init(timer_mem, &timer_count);
+       if (ret || !timer_count)
+               goto error;
+
+       for (i = 0; i < timer_count; i++) {
+               ret = arch_timer_mem_init(timer_mem);
+               if (!ret)
+                       break;
+               timer_mem++;
+       }
+
+error:
+       kfree(timer_mem);
+       return ret;
+}
+
+/* Initialize per-processor generic timer and memory-mapped timer(if present) 
*/
 static int __init arch_timer_acpi_init(struct acpi_table_header *table)
 {
-       int ret;
+       int ret, platform_timer_count;
 
        if (arch_timers_present & ARCH_TIMER_TYPE_CP15) {
                pr_warn("already initialized, skipping\n");
@@ -1089,7 +1115,7 @@ static int __init arch_timer_acpi_init(struct 
acpi_table_header *table)
 
        arch_timers_present |= ARCH_TIMER_TYPE_CP15;
 
-       ret = acpi_gtdt_init(table, NULL);
+       ret = acpi_gtdt_init(table, &platform_timer_count);
        if (ret) {
                pr_err("Failed to init GTDT table.\n");
                return ret;
@@ -1122,6 +1148,9 @@ static int __init arch_timer_acpi_init(struct 
acpi_table_header *table)
        if (ret)
                return ret;
 
+       if (arch_timer_mem_acpi_init(platform_timer_count))
+               pr_err("Failed to initialize memory-mapped timer.\n");
+
        return arch_timer_common_init();
 }
 CLOCKSOURCE_ACPI_DECLARE(arch_timer, ACPI_SIG_GTDT, arch_timer_acpi_init);
-- 
2.9.3