[PATCH RFC 3/3] nvmem: add permission flags in nvmem_config

[Srinivas Kandagatla <srinivas.kandagatla@linaro.org>]

This patch adds perm variable to nvmem_config structure which will allow
providers to specify the permissions required for the sysfs binary file.
This permission is applied on top of root-only access permissions set by
the core.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
---
 drivers/nvmem/core.c           | 1 +
 include/linux/nvmem-provider.h | 1 +
 2 files changed, 2 insertions(+)

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 414ed23..7481387 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -312,6 +312,7 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 			   config->read_only;
 	nvmem->bin = bin_attr_template;
 	nvmem->bin.attr.mode = nvmem->read_only ? : (S_IRUSR | S_IWUSR);
+	nvmem->bin.attr.mode |= config->perm;
 	nvmem->bin.size = nvmem->size;
 	device_initialize(&nvmem->dev);
 
diff --git a/include/linux/nvmem-provider.h b/include/linux/nvmem-provider.h
index 0b68caf..de9a61f 100644
--- a/include/linux/nvmem-provider.h
+++ b/include/linux/nvmem-provider.h
@@ -23,6 +23,7 @@ struct nvmem_config {
 	const struct nvmem_cell_info	*cells;
 	int			ncells;
 	bool			read_only;
+	u16			perm; /* visibility in sysfs */
 };
 
 #if IS_ENABLED(CONFIG_NVMEM)
-- 
1.9.1