imx-drm: ipu-dp: Introduce IPUV3_NUM_FLOWS

IPUv3 has a total of 3 flows (one synchronous flow and 2 asynchronous flows).

Let's add a definition for such number in order to let the code easier to
understand.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/imx-drm/ipu-v3/ipu-dp.c

@@ -46,6 +46,8 @@
 #define DP_COM_CONF_CSC_DEF_BG		(2 << 8)
 #define DP_COM_CONF_CSC_DEF_BOTH	(1 << 8)
 
+#define IPUV3_NUM_FLOWS		3
+
 struct ipu_dp_priv;
 
 struct ipu_dp {
@@ -67,7 +69,7 @@ struct ipu_dp_priv {
 	struct ipu_soc *ipu;
 	struct device *dev;
 	void __iomem *base;
-	struct ipu_flow flow[3];
+	struct ipu_flow flow[IPUV3_NUM_FLOWS];
 	struct mutex mutex;
 	int use_count;
 };
@@ -280,7 +282,7 @@ struct ipu_dp *ipu_dp_get(struct ipu_soc *ipu, unsigned int flow)
 	struct ipu_dp_priv *priv = ipu->dp_priv;
 	struct ipu_dp *dp;
 
-	if (flow > 5)
+	if ((flow >> 1) >= IPUV3_NUM_FLOWS)
 		return ERR_PTR(-EINVAL);
 
 	if (flow & 1)
@@ -322,7 +324,7 @@ int ipu_dp_init(struct ipu_soc *ipu, struct device *dev, unsigned long base)
 
 	mutex_init(&priv->mutex);
 
-	for (i = 0; i < 3; i++) {
+	for (i = 0; i < IPUV3_NUM_FLOWS; i++) {
 		priv->flow[i].foreground.foreground = 1;
 		priv->flow[i].base = priv->base + ipu_dp_flow_base[i];
 		priv->flow[i].priv = priv;