drm/exynos: scaler: Reset hardware before starting the operation

Ensure that Scaler hardware is properly reset and interrupts are cleared
before processing next image.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

diff --git a/drivers/gpu/drm/exynos/exynos_drm_scaler.c b/drivers/gpu/drm/exynos/exynos_drm_scaler.c
index 91d4382..d25069e 100644 (file)
--- a/drivers/gpu/drm/exynos/exynos_drm_scaler.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_scaler.c
@@ -30,6 +30,7 @@
 #define scaler_write(cfg, offset)      writel(cfg, scaler->regs + (offset))
 #define SCALER_MAX_CLK                 4
 #define SCALER_AUTOSUSPEND_DELAY       2000
+#define SCALER_RESET_WAIT_RETRIES      100
 
 struct scaler_data {
        const char      *clk_name[SCALER_MAX_CLK];
@@ -100,6 +101,23 @@ static u32 scaler_get_format(u32 drm_fmt)
        return 0;
 }
 
+static inline int scaler_reset(struct scaler_context *scaler)
+{
+       int retry = SCALER_RESET_WAIT_RETRIES;
+
+       scaler_write(SCALER_CFG_SOFT_RESET, SCALER_CFG);
+       do {
+               cpu_relax();
+       } while (retry > 1 &&
+                scaler_read(SCALER_CFG) & SCALER_CFG_SOFT_RESET);
+       do {
+               cpu_relax();
+               scaler_write(1, SCALER_INT_EN);
+       } while (retry > 0 && scaler_read(SCALER_INT_EN) != 1);
+
+       return retry ? 0 : -EIO;
+}
+
 static inline void scaler_enable_int(struct scaler_context *scaler)
 {
        u32 val;
@@ -354,9 +372,13 @@ static int scaler_commit(struct exynos_drm_ipp *ipp,
        u32 dst_fmt = scaler_get_format(task->dst.buf.fourcc);
        struct drm_exynos_ipp_task_rect *dst_pos = &task->dst.rect;
 
-       scaler->task = task;
-
        pm_runtime_get_sync(scaler->dev);
+       if (scaler_reset(scaler)) {
+               pm_runtime_put(scaler->dev);
+               return -EIO;
+       }
+
+       scaler->task = task;
 
        scaler_set_src_fmt(scaler, src_fmt);
        scaler_set_src_base(scaler, &task->src);
@@ -394,7 +416,11 @@ static inline void scaler_disable_int(struct scaler_context *scaler)
 
 static inline u32 scaler_get_int_status(struct scaler_context *scaler)
 {
-       return scaler_read(SCALER_INT_STATUS);
+       u32 val = scaler_read(SCALER_INT_STATUS);
+
+       scaler_write(val, SCALER_INT_STATUS);
+
+       return val;
 }
 
 static inline int scaler_task_done(u32 val)