[PATCH reworded] Revert "nvmem: add new config option"

[PATCH reworded] Revert "nvmem: add new config option"

[Rafał Miłecki]

From: Rafał Miłecki <rafal@milecki.pl>

This reverts commit 517f14d9cf3533d5ab4fded195ab6f80a92e378f.

Config option "no_of_node" is no longer needed since adding a more
explicit and targeted option "add_legacy_fixed_of_cells".

That "no_of_node" config option was needed *earlier* to help mtd's case.

DT nodes of MTD partitions (that are also NVMEM devices) may contain
subnodes. Those SHOULD NOT be treated as NVMEM fixed cells.

To prevent NVMEM core code from parsing subnodes a "no_of_node" option
was added (and set to true in mtd) to make for_each_child_of_node() in
NVMEM a no-op. That was a bit hacky because it was messing with
"of_node" pointer to achieve some side-effect.

With the introduction of "add_legacy_fixed_of_cells" config option
things got more explicit. MTD subsystem simply tells NVMEM when to look
for fixed cells and there is no need to hack "of_node" pointer anymore.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
---
Greg: I reworded this PATCH's commit message. It's hopefully clear now
      that this revert is OK only with the "add_legacy_fixed_of_cells".
---
 drivers/mtd/mtdcore.c          | 1 -
 drivers/nvmem/core.c           | 2 +-
 include/linux/nvmem-provider.h | 2 --
 3 files changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 320d8ad2babe..bb0759ca12f1 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -560,7 +560,6 @@ static int mtd_nvmem_add(struct mtd_info *mtd)
 	config.read_only = true;
 	config.root_only = true;
 	config.ignore_wp = true;
-	config.no_of_node = !of_device_is_compatible(node, "nvmem-cells");
 	config.priv = mtd;
 
 	mtd->nvmem = nvmem_register(&config);
diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 2710943f53c4..bf42b7e826db 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -935,7 +935,7 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 	nvmem->nkeepout = config->nkeepout;
 	if (config->of_node)
 		nvmem->dev.of_node = config->of_node;
-	else if (!config->no_of_node)
+	else
 		nvmem->dev.of_node = config->dev->of_node;
 
 	switch (config->id) {
diff --git a/include/linux/nvmem-provider.h b/include/linux/nvmem-provider.h
index 1b81adebdb8b..e3930835235b 100644
--- a/include/linux/nvmem-provider.h
+++ b/include/linux/nvmem-provider.h
@@ -89,7 +89,6 @@ struct nvmem_cell_info {
  * @read_only:	Device is read-only.
  * @root_only:	Device is accessibly to root only.
  * @of_node:	If given, this will be used instead of the parent's of_node.
- * @no_of_node:	Device should not use the parent's of_node even if it's !NULL.
  * @reg_read:	Callback to read data.
  * @reg_write:	Callback to write data.
  * @size:	Device size.
@@ -122,7 +121,6 @@ struct nvmem_config {
 	bool			ignore_wp;
 	struct nvmem_layout	*layout;
 	struct device_node	*of_node;
-	bool			no_of_node;
 	nvmem_reg_read_t	reg_read;
 	nvmem_reg_write_t	reg_write;
 	int	size;
-- 
2.35.3

Re: [PATCH reworded] Revert "nvmem: add new config option"

[Greg Kroah-Hartman]

On Mon, Oct 23, 2023 at 12:27:59PM +0200, Rafał Miłecki wrote:
> From: Rafał Miłecki <rafal@milecki.pl>
> 
> This reverts commit 517f14d9cf3533d5ab4fded195ab6f80a92e378f.
> 
> Config option "no_of_node" is no longer needed since adding a more
> explicit and targeted option "add_legacy_fixed_of_cells".
> 
> That "no_of_node" config option was needed *earlier* to help mtd's case.
> 
> DT nodes of MTD partitions (that are also NVMEM devices) may contain
> subnodes. Those SHOULD NOT be treated as NVMEM fixed cells.
> 
> To prevent NVMEM core code from parsing subnodes a "no_of_node" option
> was added (and set to true in mtd) to make for_each_child_of_node() in
> NVMEM a no-op. That was a bit hacky because it was messing with
> "of_node" pointer to achieve some side-effect.
> 
> With the introduction of "add_legacy_fixed_of_cells" config option
> things got more explicit. MTD subsystem simply tells NVMEM when to look
> for fixed cells and there is no need to hack "of_node" pointer anymore.
> 
> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
> Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> ---
> Greg: I reworded this PATCH's commit message. It's hopefully clear now
>       that this revert is OK only with the "add_legacy_fixed_of_cells".

Much nicer, now applied, thanks!

greg k-h