drm/mcde: dsi: Make video mode errors more verbose

Triggering an error conditions in DSI video mode only results in
a very generic "some video mode error status" error message
at the moment.

Make this more clear by adding separate error messages for each bit.
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20191106165835.2863-4-stephan@gerhold.net

drivers/gpu/drm/mcde/mcde_dsi.c

@@ -124,7 +124,27 @@ bool mcde_dsi_irq(struct mipi_dsi_device *mdsi)
 
 	val = readl(d->regs + DSI_VID_MODE_STS_FLAG);
 	if (val)
-		dev_err(d->dev, "some video mode error status\n");
+		dev_dbg(d->dev, "DSI_VID_MODE_STS_FLAG = %08x\n", val);
+	if (val & DSI_VID_MODE_STS_VSG_RUNNING)
+		dev_dbg(d->dev, "VID mode VSG running\n");
+	if (val & DSI_VID_MODE_STS_ERR_MISSING_DATA)
+		dev_err(d->dev, "VID mode missing data\n");
+	if (val & DSI_VID_MODE_STS_ERR_MISSING_HSYNC)
+		dev_err(d->dev, "VID mode missing HSYNC\n");
+	if (val & DSI_VID_MODE_STS_ERR_MISSING_VSYNC)
+		dev_err(d->dev, "VID mode missing VSYNC\n");
+	if (val & DSI_VID_MODE_STS_REG_ERR_SMALL_LENGTH)
+		dev_err(d->dev, "VID mode less bytes than expected between two HSYNC\n");
+	if (val & DSI_VID_MODE_STS_REG_ERR_SMALL_HEIGHT)
+		dev_err(d->dev, "VID mode less lines than expected between two VSYNC\n");
+	if (val & (DSI_VID_MODE_STS_ERR_BURSTWRITE |
+		   DSI_VID_MODE_STS_ERR_LINEWRITE |
+		   DSI_VID_MODE_STS_ERR_LONGREAD))
+		dev_err(d->dev, "VID mode read/write error\n");
+	if (val & DSI_VID_MODE_STS_ERR_VRS_WRONG_LENGTH)
+		dev_err(d->dev, "VID mode received packets differ from expected size\n");
+	if (val & DSI_VID_MODE_STS_VSG_RECOVERY)
+		dev_err(d->dev, "VID mode VSG in recovery mode\n");
 	writel(val, d->regs + DSI_VID_MODE_STS_CLR);
 
 	return te_received;

drivers/gpu/drm/mcde/mcde_dsi_regs.h

@@ -248,6 +248,16 @@
 
 #define DSI_VID_MODE_STS 0x000000BC
 #define DSI_VID_MODE_STS_VSG_RUNNING BIT(0)
+#define DSI_VID_MODE_STS_ERR_MISSING_DATA BIT(1)
+#define DSI_VID_MODE_STS_ERR_MISSING_HSYNC BIT(2)
+#define DSI_VID_MODE_STS_ERR_MISSING_VSYNC BIT(3)
+#define DSI_VID_MODE_STS_REG_ERR_SMALL_LENGTH BIT(4)
+#define DSI_VID_MODE_STS_REG_ERR_SMALL_HEIGHT BIT(5)
+#define DSI_VID_MODE_STS_ERR_BURSTWRITE BIT(6)
+#define DSI_VID_MODE_STS_ERR_LINEWRITE BIT(7)
+#define DSI_VID_MODE_STS_ERR_LONGREAD BIT(8)
+#define DSI_VID_MODE_STS_ERR_VRS_WRONG_LENGTH BIT(9)
+#define DSI_VID_MODE_STS_VSG_RECOVERY BIT(10)
 
 #define DSI_VID_VCA_SETTING1 0x000000C0
 #define DSI_VID_VCA_SETTING1_MAX_BURST_LIMIT_SHIFT 0