[PATCH v18 07/15] clocksource/drivers/arm_arch_timer: Refactor arch_timer_needs_probing

fu.wei
2016-12-08T17:33:11Z

When system init with device-tree, we don't know which node will be
initialized first. And the code in arch_timer_common_init should wait
until per-cpu timer and MMIO timer are both initialized. So we need
arch_timer_needs_probing to detect the init status of system.

But currently the code is dispersed in arch_timer_needs_probing and
arch_timer_common_init. And the function name doesn't specify that
it's only for device-tree. This is somewhat confusing.

This patch move all related code from arch_timer_common_init to
arch_timer_needs_probing, refactor it, and rename it to
arch_timer_needs_of_probing. And make sure that it will be called
only if acpi is disabled.

Signed-off-by: Fu Wei <fu.wei@linaro.org>
---
drivers/clocksource/arm_arch_timer.c | 34 +++++++++++++++++++---------------
1 file changed, 19 insertions(+), 15 deletions(-)

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index e554081..2c9085a 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -792,15 +792,28 @@ static const struct of_device_id arch_timer_mem_of_match[] __initconst = {
{},
};

-static bool __init
-arch_timer_needs_probing(int type, const struct of_device_id *matches)
+static bool __init arch_timer_needs_of_probing(void)
{
struct device_node *dn;
bool needs_probing = false;
+ unsigned int mask = ARCH_TIMER_TYPE_CP15 | ARCH_TIMER_TYPE_MEM;

- dn = of_find_matching_node(NULL, matches);
- if (dn && of_device_is_available(dn) && !(arch_timers_present & type))
+ /* We have two timers, and both device-tree nodes are probed. */
+ if ((arch_timers_present & mask) == mask)
+ return false;
+
+ /*
+ * Only one type of timer is probed,
+ * check if we have another type of timer node in device-tree.
+ */
+ if (arch_timers_present & ARCH_TIMER_TYPE_CP15)
+ dn = of_find_matching_node(NULL, arch_timer_mem_of_match);
+ else
+ dn = of_find_matching_node(NULL, arch_timer_of_match);
+
+ if (dn && of_device_is_available(dn))
needs_probing = true;
+
of_node_put(dn);

return needs_probing;
@@ -808,17 +821,8 @@ arch_timer_needs_probing(int type, const struct of_device_id *matches)

static int __init arch_timer_common_init(void)
{
- unsigned mask = ARCH_TIMER_TYPE_CP15 | ARCH_TIMER_TYPE_MEM;
-
- /* Wait until both nodes are probed if we have two timers */
- if ((arch_timers_present & mask) != mask) {
- if (arch_timer_needs_probing(ARCH_TIMER_TYPE_MEM,
- arch_timer_mem_of_match))
- return 0;
- if (arch_timer_needs_probing(ARCH_TIMER_TYPE_CP15,
- arch_timer_of_match))
- return 0;
- }
+ if (acpi_disabled && arch_timer_needs_of_probing())
+ return 0;

arch_timer_banner(arch_timers_present);
arch_counter_register(arch_timers_present);
--
2.9.3