[LTSI-3.14,727/894] clocksource: sh_cmt: Replace global spinlock with a per-device spinlock

Commit Message

Simon Horman Aug. 28, 2014, 7:04 a.m. UTC

From: Laurent Pinchart <[e-mail]>

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

Signed-off-by: Laurent Pinchart <[e-mail]>
Tested-by: Simon Horman <[e-mail]>
(cherry picked from commit de599c8843ebbdfc29a119c94af481b1de76700e)
Signed-off-by: Simon Horman <[e-mail]>
---
 drivers/clocksource/sh_cmt.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

Patch

diff --git a/drivers/clocksource/sh_cmt.c b/drivers/clocksource/sh_cmt.c
index fcd38db..190c655 100644
--- a/drivers/clocksource/sh_cmt.c
+++ b/drivers/clocksource/sh_cmt.c
@@ -118,6 +118,8 @@  struct sh_cmt_device {
 	void __iomem *mapbase;
 	struct clk *clk;
 
+	raw_spinlock_t lock; /* Protect the shared start/stop register */
+
 	struct sh_cmt_channel *channels;
 	unsigned int num_channels;
 
@@ -299,14 +301,12 @@  static unsigned long sh_cmt_get_counter(struct sh_cmt_channel *ch,
 	return v2;
 }
 
-static DEFINE_RAW_SPINLOCK(sh_cmt_lock);
-
 static void sh_cmt_start_stop_ch(struct sh_cmt_channel *ch, int start)
 {
 	unsigned long flags, value;
 
 	/* start stop register shared by multiple timer channels */
-	raw_spin_lock_irqsave(&sh_cmt_lock, flags);
+	raw_spin_lock_irqsave(&ch->cmt->lock, flags);
 	value = sh_cmt_read_cmstr(ch);
 
 	if (start)
@@ -315,7 +315,7 @@  static void sh_cmt_start_stop_ch(struct sh_cmt_channel *ch, int start)
 		value &= ~(1 << ch->timer_bit);
 
 	sh_cmt_write_cmstr(ch, value);
-	raw_spin_unlock_irqrestore(&sh_cmt_lock, flags);
+	raw_spin_unlock_irqrestore(&ch->cmt->lock, flags);
 }
 
 static int sh_cmt_enable(struct sh_cmt_channel *ch, unsigned long *rate)
@@ -934,6 +934,7 @@  static int sh_cmt_setup(struct sh_cmt_device *cmt, struct platform_device *pdev)
 
 	memset(cmt, 0, sizeof(*cmt));
 	cmt->pdev = pdev;
+	raw_spin_lock_init(&cmt->lock);
 
 	if (!cfg) {
 		dev_err(&cmt->pdev->dev, "missing platform data\n");