gpu: ipu-v3: Add ipu_idmac_clear_buffer()

Add the reverse of ipu_idmac_select_buffer(), that is, clear a buffer
ready status in a channel.

Signed-off-by: Steve Longerbeam <steve_longerbeam@mentor.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

2 files changed, 29 insertions, 0 deletions

diff --git a/drivers/gpu/ipu-v3/ipu-common.c b/drivers/gpu/ipu-v3/ipu-common.c
index fec72c0d18ba..773a2fc8fed4 100644
--- a/drivers/gpu/ipu-v3/ipu-common.c
+++ b/drivers/gpu/ipu-v3/ipu-common.c
@@ -357,6 +357,34 @@ void ipu_idmac_select_buffer(struct ipuv3_channel *channel, u32 buf_num)
 }
 EXPORT_SYMBOL_GPL(ipu_idmac_select_buffer);
 
+void ipu_idmac_clear_buffer(struct ipuv3_channel *channel, u32 buf_num)
+{
+        struct ipu_soc *ipu = channel->ipu;
+        unsigned int chno = channel->num;
+        unsigned long flags;
+
+        spin_lock_irqsave(&ipu->lock, flags);
+
+        ipu_cm_write(ipu, 0xF0300000, IPU_GPR); /* write one to clear */
+        switch (buf_num) {
+        case 0:
+                ipu_cm_write(ipu, idma_mask(chno), IPU_CHA_BUF0_RDY(chno));
+                break;
+        case 1:
+                ipu_cm_write(ipu, idma_mask(chno), IPU_CHA_BUF1_RDY(chno));
+                break;
+        case 2:
+                ipu_cm_write(ipu, idma_mask(chno), IPU_CHA_BUF2_RDY(chno));
+                break;
+        default:
+                break;
+        }
+        ipu_cm_write(ipu, 0x0, IPU_GPR); /* write one to set */
+
+        spin_unlock_irqrestore(&ipu->lock, flags);
+}
+EXPORT_SYMBOL_GPL(ipu_idmac_clear_buffer);
+
 int ipu_idmac_enable_channel(struct ipuv3_channel *channel)
 {
         struct ipu_soc *ipu = channel->ipu;
diff --git a/include/video/imx-ipu-v3.h b/include/video/imx-ipu-v3.h
index 10013378394e..ae44eb067f5b 100644
--- a/include/video/imx-ipu-v3.h
+++ b/include/video/imx-ipu-v3.h
@@ -167,6 +167,7 @@ void ipu_idmac_set_double_buffer(struct ipuv3_channel *channel,
 int ipu_idmac_get_current_buffer(struct ipuv3_channel *channel);
 bool ipu_idmac_buffer_is_ready(struct ipuv3_channel *channel, u32 buf_num);
 void ipu_idmac_select_buffer(struct ipuv3_channel *channel, u32 buf_num);
+void ipu_idmac_clear_buffer(struct ipuv3_channel *channel, u32 buf_num);
 
 /*
  * IPU Channel Parameter Memory (cpmem) functions