[PATCH 04/25] clocksource: sh_tmu: Replace global spinlock with a per-device spinlock

From: Daniel Lezcano
Date: Wed Jul 23 2014 - 06:58:59 EST


From: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>

The global spinlock is used to protect the shared start/stop register.
Now that all TMU channels are handled by a single device instance, use a
per-device spinlock.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
Tested-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>
---
drivers/clocksource/sh_tmu.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/clocksource/sh_tmu.c b/drivers/clocksource/sh_tmu.c
index 3eee5c8..560a31a 100644
--- a/drivers/clocksource/sh_tmu.c
+++ b/drivers/clocksource/sh_tmu.c
@@ -61,6 +61,8 @@ struct sh_tmu_device {

enum sh_tmu_model model;

+ raw_spinlock_t lock; /* Protect the shared start/stop register */
+
struct sh_tmu_channel *channels;
unsigned int num_channels;

@@ -68,8 +70,6 @@ struct sh_tmu_device {
bool has_clocksource;
};

-static DEFINE_RAW_SPINLOCK(sh_tmu_lock);
-
#define TSTR -1 /* shared register */
#define TCOR 0 /* channel register */
#define TCNT 1 /* channel register */
@@ -132,7 +132,7 @@ static void sh_tmu_start_stop_ch(struct sh_tmu_channel *ch, int start)
unsigned long flags, value;

/* start stop register shared by multiple timer channels */
- raw_spin_lock_irqsave(&sh_tmu_lock, flags);
+ raw_spin_lock_irqsave(&ch->tmu->lock, flags);
value = sh_tmu_read(ch, TSTR);

if (start)
@@ -141,7 +141,7 @@ static void sh_tmu_start_stop_ch(struct sh_tmu_channel *ch, int start)
value &= ~(1 << ch->index);

sh_tmu_write(ch, TSTR, value);
- raw_spin_unlock_irqrestore(&sh_tmu_lock, flags);
+ raw_spin_unlock_irqrestore(&ch->tmu->lock, flags);
}

static int __sh_tmu_enable(struct sh_tmu_channel *ch)
@@ -524,6 +524,8 @@ static int sh_tmu_setup(struct sh_tmu_device *tmu, struct platform_device *pdev)
tmu->pdev = pdev;
tmu->model = id->driver_data;

+ raw_spin_lock_init(&tmu->lock);
+
/* Get hold of clock. */
tmu->clk = clk_get(&tmu->pdev->dev, "fck");
if (IS_ERR(tmu->clk)) {
--
1.7.9.5

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