[PATCH 15/26] gpu: ipu-v3: Add ipu_idmac_clear_buffer()

[Philipp Zabel]

From: Steve Longerbeam <slongerbeam at gmail.com>

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 at mentor.com>
Signed-off-by: Philipp Zabel <p.zabel at pengutronix.de>
---
 drivers/gpu/ipu-v3/ipu-common.c | 28 ++++++++++++++++++++++++++++
 include/video/imx-ipu-v3.h      |  1 +
 2 files changed, 29 insertions(+)

diff --git a/drivers/gpu/ipu-v3/ipu-common.c b/drivers/gpu/ipu-v3/ipu-common.c
index fec72c0..773a2fc 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 1dc15d4..84c6477 100644
--- a/include/video/imx-ipu-v3.h
+++ b/include/video/imx-ipu-v3.h
@@ -202,6 +202,7 @@ 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
-- 
2.1.0.rc1