Re: [PATCH] video: mmp: add device tree support

On Thursday, January 09, 2014 4:32 PM, Sascha Hauer wrote:

On Thu, Jan 09, 2014 at 01:13:14PM +0800, Zhou Zhu wrote:

quoted

add device tree support for mmp fb/controller
the description at Documentation/devicetree/bindings/fb/mmp-disp.txt

Signed-off-by: Zhou Zhu <redacted>
---
 Documentation/devicetree/bindings/fb/mmp-disp.txt |   71 ++++++++++++
 drivers/video/mmp/fb/mmpfb.c                      |   71 ++++++++----
 drivers/video/mmp/hw/mmp_ctrl.c                   |  120 ++++++++++++++++-----
 3 files changed, 217 insertions(+), 45 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/fb/mmp-disp.txt

diff --git a/Documentation/devicetree/bindings/fb/mmp-disp.txt

b/Documentation/devicetree/bindings/fb/mmp-disp.txt

quoted

new file mode 100644
index 0000000..3cf2903

--- /dev/null
+++ b/Documentation/devicetree/bindings/fb/mmp-disp.txt

[.....]

quoted

+#ifdef CONFIG_OF
+	struct device_node *np;
+#else
 	struct mmp_buffer_driver_mach_info *mi;
+#endif
 	struct fb_info *info = 0;
 	struct mmpfb_info *fbi = 0;
-	int ret, modes_num;
-
-	mi = pdev->dev.platform_data;
-	if (mi = NULL) {
-		dev_err(&pdev->dev, "no platform data defined\n");
-		return -EINVAL;
-	}
+	int ret = -EINVAL, modes_num;
+	int overlay_id, dmafetch_id;
+	const char *path_name;

 	/* initialize fb */
 	info = framebuffer_alloc(sizeof(struct mmpfb_info), &pdev->dev);
 	if (info = NULL)
 		return -ENOMEM;
 	fbi = info->par;
-	if (!fbi) {
-		ret = -EINVAL;
+	if (!fbi)
+		goto failed;
+
+#ifdef CONFIG_OF

Just because your kernel build does have CONFIG_OF enabled doesn't mean
it's actually started with a devicetree. You need to make a runtime
decision, not compile time.

Yes, right.
As Sascha Hauer said, you need to make a runtime decision,
instead of compile time. Please keep the same binary for
both cases (CONFIG_OF is 'enabled' and 'disabled').

For example,

	if (pdev->dev.of_node) {
		// DT code
	} else {
		// Non-DT code
	}

Best regards,
Jingoo Han