[PATCH v4 1/5] media: atmel-isc: Add spin lock for clock enable ops

[Wenyou Yang]

Add the spin lock for the clock enable and disable operations.

Signed-off-by: Wenyou Yang <wenyou.y...@microchip.com>
---

Changes in v4: None
Changes in v3:
 - Fix the wrong used spinlock.
 - s/_/- on the subject.

Changes in v2: None

 drivers/media/platform/atmel/atmel-isc.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/atmel/atmel-isc.c 
b/drivers/media/platform/atmel/atmel-isc.c
index 2f8e345d297e..991f962b7023 100644
--- a/drivers/media/platform/atmel/atmel-isc.c
+++ b/drivers/media/platform/atmel/atmel-isc.c
@@ -65,6 +65,7 @@ struct isc_clk {
        struct clk_hw   hw;
        struct clk      *clk;
        struct regmap   *regmap;
+       spinlock_t      lock;
        u8              id;
        u8              parent_id;
        u32             div;
@@ -312,26 +313,37 @@ static int isc_clk_enable(struct clk_hw *hw)
        struct isc_clk *isc_clk = to_isc_clk(hw);
        u32 id = isc_clk->id;
        struct regmap *regmap = isc_clk->regmap;
+       unsigned long flags;
+       unsigned int status;
 
        dev_dbg(isc_clk->dev, "ISC CLK: %s, div = %d, parent id = %d\n",
                __func__, isc_clk->div, isc_clk->parent_id);
 
+       spin_lock_irqsave(&isc_clk->lock, flags);
        regmap_update_bits(regmap, ISC_CLKCFG,
                           ISC_CLKCFG_DIV_MASK(id) | ISC_CLKCFG_SEL_MASK(id),
                           (isc_clk->div << ISC_CLKCFG_DIV_SHIFT(id)) |
                           (isc_clk->parent_id << ISC_CLKCFG_SEL_SHIFT(id)));
 
        regmap_write(regmap, ISC_CLKEN, ISC_CLK(id));
+       spin_unlock_irqrestore(&isc_clk->lock, flags);
 
-       return 0;
+       regmap_read(regmap, ISC_CLKSR, &status);
+       if (status & ISC_CLK(id))
+               return 0;
+       else
+               return -EINVAL;
 }
 
 static void isc_clk_disable(struct clk_hw *hw)
 {
        struct isc_clk *isc_clk = to_isc_clk(hw);
        u32 id = isc_clk->id;
+       unsigned long flags;
 
+       spin_lock_irqsave(&isc_clk->lock, flags);
        regmap_write(isc_clk->regmap, ISC_CLKDIS, ISC_CLK(id));
+       spin_unlock_irqrestore(&isc_clk->lock, flags);
 }
 
 static int isc_clk_is_enabled(struct clk_hw *hw)
@@ -492,6 +504,7 @@ static int isc_clk_register(struct isc_device *isc, 
unsigned int id)
        isc_clk->regmap         = regmap;
        isc_clk->id             = id;
        isc_clk->dev            = isc->dev;
+       spin_lock_init(&isc_clk->lock);
 
        isc_clk->clk = clk_register(isc->dev, &isc_clk->hw);
        if (IS_ERR(isc_clk->clk)) {
-- 
2.13.0