phy: exynos-mipi-video: Use spin_lock to protct state->regmap rmw operations

The state->regmap is initialized by devm_regmap_init_mmio().
So it's fine to use spin_lock rather than mutex to protct state->regmap rmw
operations.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Tested-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
[Julia.Lawall@lip6.fr: Found an issue with the original patch w.r.t unbalanced
 spin_lock call]
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

1 files changed, 3 insertions, 6 deletions

diff --git a/drivers/phy/phy-exynos-mipi-video.c b/drivers/phy/phy-exynos-mipi-video.c
index d19649328d05..df7519a39ba0 100644
--- a/drivers/phy/phy-exynos-mipi-video.c
+++ b/drivers/phy/phy-exynos-mipi-video.c
@@ -43,7 +43,6 @@ struct exynos_mipi_video_phy {
         } phys[EXYNOS_MIPI_PHYS_NUM];
         spinlock_t slock;
         void __iomem *regs;
-        struct mutex mutex;
         struct regmap *regmap;
 };
 
@@ -59,8 +58,9 @@ static int __set_phy_state(struct exynos_mipi_video_phy *state,
         else
                 reset = EXYNOS4_MIPI_PHY_SRESETN;
 
+        spin_lock(&state->slock);
+
         if (!IS_ERR(state->regmap)) {
-                mutex_lock(&state->mutex);
                 regmap_read(state->regmap, offset, &val);
                 if (on)
                         val |= reset;
@@ -72,11 +72,9 @@ static int __set_phy_state(struct exynos_mipi_video_phy *state,
                 else if (!(val & EXYNOS4_MIPI_PHY_RESET_MASK))
                         val &= ~EXYNOS4_MIPI_PHY_ENABLE;
                 regmap_write(state->regmap, offset, val);
-                mutex_unlock(&state->mutex);
         } else {
                 addr = state->regs + EXYNOS_MIPI_PHY_CONTROL(id / 2);
 
-                spin_lock(&state->slock);
                 val = readl(addr);
                 if (on)
                         val |= reset;
@@ -90,9 +88,9 @@ static int __set_phy_state(struct exynos_mipi_video_phy *state,
                         val &= ~EXYNOS4_MIPI_PHY_ENABLE;
 
                 writel(val, addr);
-                spin_unlock(&state->slock);
         }
 
+        spin_unlock(&state->slock);
         return 0;
 }
 
@@ -158,7 +156,6 @@ static int exynos_mipi_video_phy_probe(struct platform_device *pdev)
 
         dev_set_drvdata(dev, state);
         spin_lock_init(&state->slock);
-        mutex_init(&state->mutex);
 
         for (i = 0; i < EXYNOS_MIPI_PHYS_NUM; i++) {
                 struct phy *phy = devm_phy_create(dev, NULL,