drm/imx: Match imx-ipuv3-crtc components using device node in platform data

BugLink: http://bugs.launchpad.net/bugs/1590455

commit 310944d1 upstream.

The component master driver imx-drm-core matches component devices using
their of_node. Since commit 950b410dd1ab ("gpu: ipu-v3: Fix imx-ipuv3-crtc
module autoloading"), the imx-ipuv3-crtc dev->of_node is not set during
probing. Before that, of_node was set and caused an of: modalias to be
used instead of the platform: modalias, which broke module autoloading.

On the other hand, if dev->of_node is not set yet when the imx-ipuv3-crtc
probe function calls component_add, component matching in imx-drm-core
fails. While dev->of_node will be set once the next component tries to
bring up the component master, imx-drm-core component binding will never
succeed if one of the crtc devices is probed last.

Add of_node to the component platform data and match against the
pdata->of_node instead of dev->of_node in imx-drm-core to work around
this problem.

Fixes: 950b410dd1ab ("gpu: ipu-v3: Fix imx-ipuv3-crtc module autoloading")
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Tested-by: Fabio Estevam <fabio.estevam@nxp.com>
Tested-by: Lothar Waßmann <LW@KARO-electronics.de>
Tested-by: Heiko Schocher <hs@denx.de>
Tested-by: Chris Ruehl <chris.ruehl@gtsys.com.hk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

drivers/gpu/drm/imx/imx-drm-core.c

@@ -26,6 +26,7 @@
 #include <drm/drm_fb_cma_helper.h>
 #include <drm/drm_plane_helper.h>
 #include <drm/drm_of.h>
+#include <video/imx-ipu-v3.h>
 
 #include "imx-drm.h"
 
@@ -505,6 +506,13 @@ static int compare_of(struct device *dev, void *data)
 {
 	struct device_node *np = data;
 
+	/* Special case for DI, dev->of_node may not be set yet */
+	if (strcmp(dev->driver->name, "imx-ipuv3-crtc") == 0) {
+		struct ipu_client_platformdata *pdata = dev->platform_data;
+
+		return pdata->of_node == np;
+	}
+
 	/* Special case for LDB, one device for two channels */
 	if (of_node_cmp(np->name, "lvds-channel") == 0) {
 		np = of_get_parent(np);

drivers/gpu/drm/imx/ipuv3-crtc.c

@@ -369,7 +369,7 @@ static int ipu_crtc_init(struct ipu_crtc *ipu_crtc,
 
 	ret = imx_drm_add_crtc(drm, &ipu_crtc->base, &ipu_crtc->imx_crtc,
 			&ipu_crtc->plane[0]->base, &ipu_crtc_helper_funcs,
-			ipu_crtc->dev->of_node);
+			pdata->of_node);
 	if (ret) {
 		dev_err(ipu_crtc->dev, "adding crtc failed with %d.\n", ret);
 		goto err_put_resources;

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

@@ -997,7 +997,7 @@ struct ipu_platform_reg {
 };
 
 /* These must be in the order of the corresponding device tree port nodes */
-static const struct ipu_platform_reg client_reg[] = {
+static struct ipu_platform_reg client_reg[] = {
 	{
 		.pdata = {
 			.csi = 0,
@@ -1048,7 +1048,7 @@ static int ipu_add_client_devices(struct ipu_soc *ipu, unsigned long ipu_base)
 	mutex_unlock(&ipu_client_id_mutex);
 
 	for (i = 0; i < ARRAY_SIZE(client_reg); i++) {
-		const struct ipu_platform_reg *reg = &client_reg[i];
+		struct ipu_platform_reg *reg = &client_reg[i];
 		struct platform_device *pdev;
 		struct device_node *of_node;
 
@@ -1070,6 +1070,7 @@ static int ipu_add_client_devices(struct ipu_soc *ipu, unsigned long ipu_base)
 
 		pdev->dev.parent = dev;
 
+		reg->pdata.of_node = of_node;
 		ret = platform_device_add_data(pdev, &reg->pdata,
 					       sizeof(reg->pdata));
 		if (!ret)

include/video/imx-ipu-v3.h

@@ -16,6 +16,7 @@
 #include <linux/videodev2.h>
 #include <linux/bitmap.h>
 #include <linux/fb.h>
+#include <linux/of.h>
 #include <media/v4l2-mediabus.h>
 #include <video/videomode.h>
 
@@ -344,6 +345,7 @@ struct ipu_client_platformdata {
 	int dc;
 	int dp;
 	int dma[2];
+	struct device_node *of_node;
 };
 
 #endif /* __DRM_IPU_H__ */