On 03/10/2016 09:22 AM, Roger Quadros wrote:

Franklin,

On 10/03/16 15:40, Franklin S Cooper Jr. wrote:

quoted

On 03/10/2016 06:40 AM, Roger Quadros wrote:

quoted

Franklin,

On 10/03/16 06:07, Franklin S Cooper Jr wrote:

quoted

The dma channel information is located within the GPMC node. The NAND
driver requires a handle to the GPMC's dev to properly parse the DMA
properties. Therefore, store a handle to the dev so it can be referenced
within the NAND driver.

Signed-off-by: Franklin S Cooper Jr <redacted>
---
 drivers/memory/omap-gpmc.c                   | 1 +
 include/linux/platform_data/mtd-nand-omap2.h | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/drivers/memory/omap-gpmc.c b/drivers/memory/omap-gpmc.c
index 6515dfc..2932d13 100644
--- a/drivers/memory/omap-gpmc.c
+++ b/drivers/memory/omap-gpmc.c

@@ -1796,6 +1796,7 @@ static int gpmc_probe_nand_child(struct platform_device *pdev,
 
 	gpmc_nand_data->cs = val;
 	gpmc_nand_data->of_node = child;
+	gpmc_nand_data->gpmc_dev = &pdev->dev;
 
 	/* Detect availability of ELM module */
 	gpmc_nand_data->elm_of_node = of_parse_phandle(child, "ti,elm-id", 0);

diff --git a/include/linux/platform_data/mtd-nand-omap2.h b/include/linux/platform_data/mtd-nand-omap2.h
index 090bbab..534b984 100644
--- a/include/linux/platform_data/mtd-nand-omap2.h
+++ b/include/linux/platform_data/mtd-nand-omap2.h

@@ -80,5 +80,7 @@ struct omap_nand_platform_data {
 	/* for passing the partitions */
 	struct device_node	*of_node;
 	struct device_node	*elm_of_node;
+
+	struct device		*gpmc_dev;
 };
 #endif

Why do you need this? Can't we just use dev->parent in the omap2-nand driver?

The omap2-nand platform_device is created by
platform_device_alloc. The created platform_device dev
parent isn't by default set to the GPMC dev. I didn't think
this was the right approach to manually set the parent
property. However, taking a look at other usages of
platform_device_alloc it seems this is actually pretty
common. If your ok with this then I can go that route.

After my DT cleanup we no longer use platform_dev_alloc for DT cases.
As Nand node is child of GPMC node, omap2 nand's parent is guaranteed to be the
GPMC device.

But for legacy boot we still use gpmc_nand_init() which calls platform_device_add()
without setting pdev->parent and so it will set the parent to platform bus.

Maybe we could patch gpmc_nand_init() to set NAND's parent to GPMC device?

Yup that was my plan. I'll send a rev 4 with this change and
also your comments on PATCH 2.

cheers,
-roger