fbdev: sh_mobile_lcdc: Return display connection state in display_on

Return true if the display is connected and false otherwise. Set the fb
info state to FBINFO_STATE_SUSPENDED in the sh_mobile_lcdc driver when
the display is not connected.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

drivers/video/sh_mipi_dsi.c

@@ -412,7 +412,7 @@ static int mipi_display_on(struct sh_mobile_lcdc_entity *entity)
 
 	sh_mipi_dsi_enable(mipi, true);
 
-	return 0;
+	return SH_MOBILE_LCDC_DISPLAY_CONNECTED;
 
 mipi_display_on_fail1:
 	pm_runtime_put_sync(&mipi->pdev->dev);

drivers/video/sh_mobile_hdmi.c

@@ -1004,9 +1004,9 @@ static int sh_hdmi_display_on(struct sh_mobile_lcdc_entity *entity)
 {
 	struct sh_hdmi *hdmi = entity_to_sh_hdmi(entity);
 	struct sh_mobile_lcdc_chan *ch = entity->lcdc;
-	struct fb_info *info = ch->info;
 
-	dev_dbg(hdmi->dev, "%s(%p): state %x\n", __func__, hdmi, info->state);
+	dev_dbg(hdmi->dev, "%s(%p): state %x\n", __func__, hdmi,
+		hdmi->hp_state);
 
 	/*
 	 * hp_state can be set to
@@ -1021,12 +1021,13 @@ static int sh_hdmi_display_on(struct sh_mobile_lcdc_entity *entity)
 		dev_dbg(hdmi->dev, "HDMI running\n");
 		break;
 	case HDMI_HOTPLUG_DISCONNECTED:
-		info->state = FBINFO_STATE_SUSPENDED;
 	default:
 		hdmi->var = ch->display_var;
 	}
 
-	return 0;
+	return hdmi->hp_state == HDMI_HOTPLUG_DISCONNECTED
+		? SH_MOBILE_LCDC_DISPLAY_DISCONNECTED
+		: SH_MOBILE_LCDC_DISPLAY_CONNECTED;
 }
 
 static void sh_hdmi_display_off(struct sh_mobile_lcdc_entity *entity)

drivers/video/sh_mobile_lcdcfb.c

@@ -338,8 +338,14 @@ static void sh_mobile_lcdc_display_on(struct sh_mobile_lcdc_chan *ch)
 	struct sh_mobile_lcdc_panel_cfg *panel = &ch->cfg.panel_cfg;
 
 	if (ch->tx_dev) {
-		if (ch->tx_dev->ops->display_on(ch->tx_dev) < 0)
+		int ret;
+
+		ret = ch->tx_dev->ops->display_on(ch->tx_dev);
+		if (ret < 0)
 			return;
+
+		if (ret == SH_MOBILE_LCDC_DISPLAY_DISCONNECTED)
+			ch->info->state = FBINFO_STATE_SUSPENDED;
 	}
 
 	/* HDMI must be enabled before LCDC configuration */

drivers/video/sh_mobile_lcdcfb.h

@@ -21,6 +21,9 @@ struct sh_mobile_lcdc_entity;
 struct sh_mobile_lcdc_priv;
 struct sh_mobile_lcdc_chan;
 
+#define SH_MOBILE_LCDC_DISPLAY_DISCONNECTED	0
+#define SH_MOBILE_LCDC_DISPLAY_CONNECTED	1
+
 struct sh_mobile_lcdc_entity_ops {
 	/* Display */
 	int (*display_on)(struct sh_mobile_lcdc_entity *entity);