[PATCH 1/4] gpu: ipu-v3: pre: add double buffer status readback

[Lucas Stach]

This allows the upper layers to check if a double buffer update has
been applied by the PRE or is still pending.

Signed-off-by: Lucas Stach <l.stach at pengutronix.de>
---
 drivers/gpu/ipu-v3/ipu-pre.c | 6 ++++++
 drivers/gpu/ipu-v3/ipu-prv.h | 1 +
 2 files changed, 7 insertions(+)

diff --git a/drivers/gpu/ipu-v3/ipu-pre.c b/drivers/gpu/ipu-v3/ipu-pre.c
index 2f8db9d62551..7389ad157fd6 100644
--- a/drivers/gpu/ipu-v3/ipu-pre.c
+++ b/drivers/gpu/ipu-v3/ipu-pre.c
@@ -259,6 +259,12 @@ void ipu_pre_update(struct ipu_pre *pre, unsigned int bufaddr)
 	writel(IPU_PRE_CTRL_SDW_UPDATE, pre->regs + IPU_PRE_CTRL_SET);
 }
 
+bool ipu_pre_update_done(struct ipu_pre *pre)
+{
+	return !(readl_relaxed(pre->regs + IPU_PRE_CTRL) &
+		 IPU_PRE_CTRL_SDW_UPDATE);
+}
+
 u32 ipu_pre_get_baddr(struct ipu_pre *pre)
 {
 	return (u32)pre->buffer_paddr;
diff --git a/drivers/gpu/ipu-v3/ipu-prv.h b/drivers/gpu/ipu-v3/ipu-prv.h
index d6beee99b6b8..215d342d8441 100644
--- a/drivers/gpu/ipu-v3/ipu-prv.h
+++ b/drivers/gpu/ipu-v3/ipu-prv.h
@@ -272,6 +272,7 @@ void ipu_pre_configure(struct ipu_pre *pre, unsigned int width,
 		       unsigned int height, unsigned int stride, u32 format,
 		       uint64_t modifier, unsigned int bufaddr);
 void ipu_pre_update(struct ipu_pre *pre, unsigned int bufaddr);
+bool ipu_pre_update_done(struct ipu_pre *pre);
 
 struct ipu_prg *ipu_prg_lookup_by_phandle(struct device *dev, const char *name,
 					  int ipu_id);
-- 
2.19.0