[PATCH v16 14/15] 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 | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/drivers/clocksource/arm_arch_timer.c 
b/drivers/clocksource/arm_arch_timer.c
index c494ca8..0aad60a 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -1067,7 +1067,28 @@ 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(void)
+{
+       struct arch_timer_mem *timer_mem;
+       int ret = 0;
+       int i = 0;
+
+       timer_mem = kzalloc(sizeof(*timer_mem), GFP_KERNEL);
+       if (!timer_mem)
+               return -ENOMEM;
+
+       while (!gtdt_arch_timer_mem_init(timer_mem, i)) {
+               ret = arch_timer_mem_init(timer_mem);
+               if (ret)
+                       break;
+               i++;
+       }
+
+       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;
@@ -1104,6 +1125,9 @@ static int __init arch_timer_acpi_init(struct 
acpi_table_header *table)
        /* Get the frequency from CNTFRQ */
        arch_timer_detect_rate(NULL);
 
+       if (arch_timer_mem_acpi_init())
+               pr_err("Failed to initialize memory-mapped timer.\n");
+
        ret = arch_timer_init();
 
 error:
-- 
2.7.4