Re: [PATCH] nvmem: core: add support to NVMEM_NO_SYSFS_ENTRY

From: Gaurav Kohli
Date: Tue Aug 04 2020 - 10:26:51 EST


Please ignore this patch, some problem in my git send mail.
Apologies for the spam.


On 8/4/2020 7:44 PM, Gaurav Kohli wrote:
From: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>

Some users might not want to expose nvmem entry to sysfs and
only intend to use kernel interface so add such provision.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
---
Documentation/ABI/stable/sysfs-bus-nvmem | 2 ++
drivers/nvmem/Kconfig | 5 +++++
drivers/nvmem/core.c | 11 ++++++-----
3 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/Documentation/ABI/stable/sysfs-bus-nvmem
b/Documentation/ABI/stable/sysfs-bus-nvmem
index 5923ab4620c5..12aab0a85fea 100644
--- a/Documentation/ABI/stable/sysfs-bus-nvmem
+++ b/Documentation/ABI/stable/sysfs-bus-nvmem
@@ -6,6 +6,8 @@ Description:
This file allows user to read/write the raw NVMEM contents.
Permissions for write to this file depends on the nvmem
provider configuration.
+ Note: This file is not present if CONFIG_NVMEM_NO_SYSFS_ENTRY
+ is enabled

ex:
hexdump /sys/bus/nvmem/devices/qfprom0/nvmem
diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index 0a7a470ee859..6ab3276d287c 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -192,4 +192,9 @@ config SC27XX_EFUSE
This driver can also be built as a module. If so, the module
will be called nvmem-sc27xx-efuse.

+config NVMEM_NO_SYSFS_ENTRY
+ bool "No nvmem sysfs entry"
+
+ help
+ Say Yes if you do not want to add nvmem entry to sysfs.
endif
diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index b9a0270883a0..c70f183fe379 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -216,7 +216,7 @@ static const struct attribute_group
nvmem_bin_rw_group = {
.attrs = nvmem_attrs,
};

-static const struct attribute_group *nvmem_rw_dev_groups[] = {
+static const __maybe_unused struct attribute_group
*nvmem_rw_dev_groups[] = {
&nvmem_bin_rw_group,
NULL,
};
@@ -240,7 +240,7 @@ static const struct attribute_group
nvmem_bin_ro_group = {
.attrs = nvmem_attrs,
};

-static const struct attribute_group *nvmem_ro_dev_groups[] = {
+static const __maybe_unused struct attribute_group
*nvmem_ro_dev_groups[] = {
&nvmem_bin_ro_group,
NULL,
};
@@ -265,7 +265,7 @@ static const struct attribute_group
nvmem_bin_rw_root_group = {
.attrs = nvmem_attrs,
};

-static const struct attribute_group *nvmem_rw_root_dev_groups[] = {
+static const __maybe_unused struct attribute_group
*nvmem_rw_root_dev_groups[] = {
&nvmem_bin_rw_root_group,
NULL,
};
@@ -289,7 +289,7 @@ static const struct attribute_group
nvmem_bin_ro_root_group = {
.attrs = nvmem_attrs,
};

-static const struct attribute_group *nvmem_ro_root_dev_groups[] = {
+static const __maybe_unused struct attribute_group
*nvmem_ro_root_dev_groups[] = {
&nvmem_bin_ro_root_group,
NULL,
};
@@ -688,6 +688,7 @@ struct nvmem_device *nvmem_register(const struct
nvmem_config *config)
nvmem->read_only = device_property_present(config->dev, "read-only") |
config->read_only;

+#if !defined(CONFIG_NVMEM_NO_SYSFS_ENTRY)
if (config->root_only)
nvmem->dev.groups = nvmem->read_only ?
nvmem_ro_root_dev_groups :
@@ -696,7 +697,7 @@ struct nvmem_device *nvmem_register(const struct
nvmem_config *config)
nvmem->dev.groups = nvmem->read_only ?
nvmem_ro_dev_groups :
nvmem_rw_dev_groups;
-
+#endif
device_initialize(&nvmem->dev);

dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name);


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