clocksource: sh_cmt: Replace global spinlock with a per-device spinlock

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 <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Simon Horman <horms+renesas@verge.net.au>
(cherry picked from commit de599c8843ebbdfc29a119c94af481b1de76700e)
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

diff --git a/drivers/clocksource/sh_cmt.c b/drivers/clocksource/sh_cmt.c
index fcd38db..190c655 100644 (file)
--- 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");