gpu: ipu-v3: smfc: Add ipu_smfc_set_watermark()

Adds ipu_smfc_set_watermark() which programs a channel's SMFC FIFO
levels at which the watermark signal is set and cleared.
Signed-off-by: Steve Longerbeam <steve_longerbeam@mentor.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

drivers/gpu/ipu-v3/ipu-smfc.c

@@ -80,6 +80,26 @@ int ipu_smfc_map_channel(struct ipu_smfc *smfc, int csi_id, int mipi_id)
 }
 EXPORT_SYMBOL_GPL(ipu_smfc_map_channel);
 
+int ipu_smfc_set_watermark(struct ipu_smfc *smfc, u32 set_level, u32 clr_level)
+{
+	struct ipu_smfc_priv *priv = smfc->priv;
+	unsigned long flags;
+	u32 val, shift;
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	shift = smfc->chno * 6 + (smfc->chno > 1 ? 4 : 0);
+	val = readl(priv->base + SMFC_WMC);
+	val &= ~(0x3f << shift);
+	val |= ((clr_level << 3) | set_level) << shift;
+	writel(val, priv->base + SMFC_WMC);
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ipu_smfc_set_watermark);
+
 int ipu_smfc_enable(struct ipu_smfc *smfc)
 {
 	struct ipu_smfc_priv *priv = smfc->priv;

include/video/imx-ipu-v3.h

@@ -296,6 +296,7 @@ int ipu_smfc_enable(struct ipu_smfc *smfc);
 int ipu_smfc_disable(struct ipu_smfc *smfc);
 int ipu_smfc_map_channel(struct ipu_smfc *smfc, int csi_id, int mipi_id);
 int ipu_smfc_set_burstsize(struct ipu_smfc *smfc, int burstsize);
+int ipu_smfc_set_watermark(struct ipu_smfc *smfc, u32 set_level, u32 clr_level);
 
 enum ipu_color_space ipu_drm_fourcc_to_colorspace(u32 drm_fourcc);
 enum ipu_color_space ipu_pixelformat_to_colorspace(u32 pixelformat);