[PATCH v3 1/5] media: atmel-isc: Add spin lock for clock enable ops

From: Wenyou Yang
Date: Thu Sep 28 2017 - 04:20:58 EST


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

Signed-off-by: Wenyou Yang <wenyou.yang@xxxxxxxxxxxxx>
---

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