clocksource: sh_mtu2: Replace global spinlock with a per-device spinlock

The global spinlock is used to protect the shared start/stop register.
Now that all MTU2 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: Wolfram Sang <wsa@sang-engineering.com>
(cherry picked from commit 8b2463d8cae2dda0c98ab5a15f25a0350a0e998d)
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

diff --git a/drivers/clocksource/sh_mtu2.c b/drivers/clocksource/sh_mtu2.c
index 0342e4a..b0c229f 100644 (file)
--- a/drivers/clocksource/sh_mtu2.c
+++ b/drivers/clocksource/sh_mtu2.c
@@ -47,14 +47,14 @@ struct sh_mtu2_device {
        void __iomem *mapbase;
        struct clk *clk;
 
+       raw_spinlock_t lock; /* Protect the shared registers */
+
        struct sh_mtu2_channel *channels;
        unsigned int num_channels;
 
        bool has_clockevent;
 };
 
-static DEFINE_RAW_SPINLOCK(sh_mtu2_lock);
-
 #define TSTR -1 /* shared register */
 #define TCR  0 /* channel register */
 #define TMDR 1 /* channel register */
@@ -192,7 +192,7 @@ static void sh_mtu2_start_stop_ch(struct sh_mtu2_channel *ch, int start)
        unsigned long flags, value;
 
        /* start stop register shared by multiple timer channels */
-       raw_spin_lock_irqsave(&sh_mtu2_lock, flags);
+       raw_spin_lock_irqsave(&ch->mtu->lock, flags);
        value = sh_mtu2_read(ch, TSTR);
 
        if (start)
@@ -201,7 +201,7 @@ static void sh_mtu2_start_stop_ch(struct sh_mtu2_channel *ch, int start)
                value &= ~(1 << ch->index);
 
        sh_mtu2_write(ch, TSTR, value);
-       raw_spin_unlock_irqrestore(&sh_mtu2_lock, flags);
+       raw_spin_unlock_irqrestore(&ch->mtu->lock, flags);
 }
 
 static int sh_mtu2_enable(struct sh_mtu2_channel *ch)
@@ -402,6 +402,8 @@ static int sh_mtu2_setup(struct sh_mtu2_device *mtu,
 
        mtu->pdev = pdev;
 
+       raw_spin_lock_init(&mtu->lock);
+
        /* Get hold of clock. */
        mtu->clk = clk_get(&mtu->pdev->dev, "fck");
        if (IS_ERR(mtu->clk)) {