[PATCH v15 12/13] clocksource/drivers/arm_arch_timer: Add GTDT support for memory-mapped timer

[fu . wei]

From: Fu Wei <fu.wei@xxxxxxxxxx>

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.wei@xxxxxxxxxx>
---
 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 653374c..350d0b9 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -1053,7 +1053,28 @@ 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;
@@ -1090,6 +1111,9 @@ static int __init arch_timer_acpi_init(struct acpi_table_header *table)
 	/* Get the frequency from CNTFRQ */
 	arch_timer_detect_rate(NULL, NULL);
 
+	if (arch_timer_mem_acpi_init())
+		pr_err("Failed to initialize memory-mapped timer.\n");
+
 	ret = arch_timer_init();
 
 error:
-- 
2.7.4