[PATCH v18 14/15] clocksource/drivers/arm_arch_timer: Add GTDT support for memory-mapped timer

fu.wei
2016-12-08T17:33:18Z

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@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 7f059f9..1fe1c08 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -1054,10 +1054,36 @@ 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");
@@ -1066,7 +1092,7 @@ 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;
@@ -1099,6 +1125,9 @@ 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