6 files changed, 30 insertions, 5 deletions

diff --git a/drivers/gpu/drm/sun4i/sun4i_backend.c b/drivers/gpu/drm/sun4i/sun4i_backend.c
index d660741ba475..95a77c6a9161 100644
--- a/drivers/gpu/drm/sun4i/sun4i_backend.c
+++ b/drivers/gpu/drm/sun4i/sun4i_backend.c
@@ -19,6 +19,7 @@
 #include <drm/drm_plane_helper.h>
 
 #include <linux/component.h>
+#include <linux/list.h>
 #include <linux/reset.h>
 
 #include "sun4i_backend.h"
@@ -310,7 +311,6 @@ static int sun4i_backend_bind(struct device *dev, struct device *master,
 	if (!backend)
 		return -ENOMEM;
 	dev_set_drvdata(dev, backend);
-	drv->backend = backend;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	regs = devm_ioremap_resource(dev, res);
@@ -369,6 +369,8 @@ static int sun4i_backend_bind(struct device *dev, struct device *master,
 		}
 	}
 
+	list_add_tail(&backend->list, &drv->backend_list);
+
 	/* Reset the registers */
 	for (i = 0x800; i < 0x1000; i += 4)
 		regmap_write(backend->regs, i, 0);
@@ -400,6 +402,8 @@ static void sun4i_backend_unbind(struct device *dev, struct device *master,
 {
 	struct sun4i_backend *backend = dev_get_drvdata(dev);
 
+	list_del(&backend->list);
+
 	if (of_device_is_compatible(dev->of_node,
 				    "allwinner,sun8i-a33-display-backend"))
 		sun4i_backend_free_sat(dev);
diff --git a/drivers/gpu/drm/sun4i/sun4i_backend.h b/drivers/gpu/drm/sun4i/sun4i_backend.h
index 83e63cc702b4..9c8287309c65 100644
--- a/drivers/gpu/drm/sun4i/sun4i_backend.h
+++ b/drivers/gpu/drm/sun4i/sun4i_backend.h
@@ -14,6 +14,7 @@
 #define _SUN4I_BACKEND_H_
 
 #include <linux/clk.h>
+#include <linux/list.h>
 #include <linux/regmap.h>
 #include <linux/reset.h>
 
@@ -149,6 +150,9 @@ struct sun4i_backend {
 
 	struct clk		*sat_clk;
 	struct reset_control	*sat_reset;
+
+	/* Backend list management */
+	struct list_head	list;
 };
 
 void sun4i_backend_apply_color_correction(struct sun4i_backend *backend);
diff --git a/drivers/gpu/drm/sun4i/sun4i_drv.c b/drivers/gpu/drm/sun4i/sun4i_drv.c
index 8ddd72cd5873..c52f7a9eb045 100644
--- a/drivers/gpu/drm/sun4i/sun4i_drv.c
+++ b/drivers/gpu/drm/sun4i/sun4i_drv.c
@@ -91,6 +91,8 @@ static int sun4i_drv_bind(struct device *dev)
 		goto free_drm;
 	}
 	drm->dev_private = drv;
+	INIT_LIST_HEAD(&drv->backend_list);
+	INIT_LIST_HEAD(&drv->tcon_list);
 
 	ret = of_reserved_mem_device_init(dev);
 	if (ret && ret != -ENODEV) {
diff --git a/drivers/gpu/drm/sun4i/sun4i_drv.h b/drivers/gpu/drm/sun4i/sun4i_drv.h
index 5df50126ff52..250c29017ef5 100644
--- a/drivers/gpu/drm/sun4i/sun4i_drv.h
+++ b/drivers/gpu/drm/sun4i/sun4i_drv.h
@@ -14,11 +14,12 @@
 #define _SUN4I_DRV_H_
 
 #include <linux/clk.h>
+#include <linux/list.h>
 #include <linux/regmap.h>
 
 struct sun4i_drv {
-	struct sun4i_backend	*backend;
-	struct sun4i_tcon	*tcon;
+	struct list_head	backend_list;
+	struct list_head	tcon_list;
 
 	struct drm_fbdev_cma	*fbdev;
 };
diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
index 9a83a85529ac..5adb643ed41d 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
@@ -25,6 +25,7 @@
 #include <linux/regmap.h>
 #include <linux/reset.h>
 
+#include "sun4i_backend.h"
 #include "sun4i_crtc.h"
 #include "sun4i_dotclock.h"
 #include "sun4i_drv.h"
@@ -407,14 +408,18 @@ static int sun4i_tcon_bind(struct device *dev, struct device *master,
 {
 	struct drm_device *drm = data;
 	struct sun4i_drv *drv = drm->dev_private;
+	struct sun4i_backend *backend;
 	struct sun4i_tcon *tcon;
 	int ret;
 
+	/* Wait for a backend to be registered */
+	if (list_empty(&drv->backend_list))
+		return -EPROBE_DEFER;
+
 	tcon = devm_kzalloc(dev, sizeof(*tcon), GFP_KERNEL);
 	if (!tcon)
 		return -ENOMEM;
 	dev_set_drvdata(dev, tcon);
-	drv->tcon = tcon;
 	tcon->drm = drm;
 	tcon->dev = dev;
 	tcon->quirks = of_device_get_match_data(dev);
@@ -459,7 +464,9 @@ static int sun4i_tcon_bind(struct device *dev, struct device *master,
 		goto err_free_dotclock;
 	}
 
-	tcon->crtc = sun4i_crtc_init(drm, drv->backend, tcon);
+	backend = list_first_entry(&drv->backend_list,
+				   struct sun4i_backend, list);
+	tcon->crtc = sun4i_crtc_init(drm, backend, tcon);
 	if (IS_ERR(tcon->crtc)) {
 		dev_err(dev, "Couldn't create our CRTC\n");
 		ret = PTR_ERR(tcon->crtc);
@@ -470,6 +477,8 @@ static int sun4i_tcon_bind(struct device *dev, struct device *master,
 	if (ret < 0)
 		goto err_free_clocks;
 
+	list_add_tail(&tcon->list, &drv->tcon_list);
+
 	return 0;
 
 err_free_dotclock:
@@ -486,6 +495,7 @@ static void sun4i_tcon_unbind(struct device *dev, struct device *master,
 {
 	struct sun4i_tcon *tcon = dev_get_drvdata(dev);
 
+	list_del(&tcon->list);
 	sun4i_dclk_free(tcon);
 	sun4i_tcon_free_clocks(tcon);
 }
diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.h b/drivers/gpu/drm/sun4i/sun4i_tcon.h
index f636343a935d..1bda4d183eec 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.h
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.h
@@ -17,6 +17,7 @@
 #include <drm/drm_crtc.h>
 
 #include <linux/kernel.h>
+#include <linux/list.h>
 #include <linux/reset.h>
 
 #define SUN4I_TCON_GCTL_REG			0x0
@@ -172,6 +173,9 @@ struct sun4i_tcon {
 
 	/* Associated crtc */
 	struct sun4i_crtc		*crtc;
+
+	/* TCON list management */
+	struct list_head		list;
 };
 
 struct drm_bridge *sun4i_tcon_find_bridge(struct device_node *node);