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Commit 9b065932 authored by qctecmdr's avatar qctecmdr Committed by Gerrit - the friendly Code Review server
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Merge "nvmem: core: add NVMEM_SYSFS Kconfig"

parents 9b7afd65 48dc3910

Documentation/ABI/stable/sysfs-bus-nvmem

+2 −0
Original line number Diff line number Diff line
@@ -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 only present if CONFIG_NVMEM_SYSFS

		is enabled



		ex:

		hexdump /sys/bus/nvmem/devices/qfprom0/nvmem

drivers/nvmem/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -13,6 +13,16 @@ menuconfig NVMEM 


if NVMEM



config NVMEM_SYSFS

	bool "/sys/bus/nvmem/devices/*/nvmem (sysfs interface)"

	depends on SYSFS

	default y

	help

	 Say Y here to add a sysfs interface for NVMEM.



	 This interface is mostly used by userspace applications to

	 read/write directly into nvmem.



config NVMEM_IMX_IIM

	tristate "i.MX IC Identification Module support"

	depends on ARCH_MXC || COMPILE_TEST

drivers/nvmem/Makefile

+3 −0
Original line number Diff line number Diff line
@@ -6,6 +6,9 @@ 
obj-$(CONFIG_NVMEM)		+= nvmem_core.o

nvmem_core-y			:= core.o



obj-$(CONFIG_NVMEM_SYSFS)	+= nvmem_sysfs.o

nvmem_sysfs-y			:= nvmem-sysfs.o



# Devices

obj-$(CONFIG_NVMEM_BCM_OCOTP)	+= nvmem-bcm-ocotp.o

nvmem-bcm-ocotp-y		:= bcm-ocotp.o

drivers/nvmem/core.c

+4 −233
Original line number Diff line number Diff line
@@ -25,25 +25,7 @@ 
#include <linux/of.h>

#include <linux/slab.h>



struct nvmem_device {

	const char		*name;

	struct module		*owner;

	struct device		dev;

	int			stride;

	int			word_size;

	int			id;

	int			users;

	size_t			size;

	bool			read_only;

	int			flags;

	struct bin_attribute	eeprom;

	struct device		*base_dev;

	nvmem_reg_read_t	reg_read;

	nvmem_reg_write_t	reg_write;

	void *priv;

};



#define FLAG_COMPAT		BIT(0)

#include "nvmem.h"



struct nvmem_cell {

	const char		*name;
@@ -61,11 +43,6 @@ static DEFINE_IDA(nvmem_ida); 
static LIST_HEAD(nvmem_cells);

static DEFINE_MUTEX(nvmem_cells_mutex);



#ifdef CONFIG_DEBUG_LOCK_ALLOC

static struct lock_class_key eeprom_lock_key;

#endif



#define to_nvmem_device(d) container_of(d, struct nvmem_device, dev)

static int nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset,

			  void *val, size_t bytes)

{
@@ -84,168 +61,6 @@ static int nvmem_reg_write(struct nvmem_device *nvmem, unsigned int offset, 
	return -EINVAL;

}



static ssize_t bin_attr_nvmem_read(struct file *filp, struct kobject *kobj,

				    struct bin_attribute *attr,

				    char *buf, loff_t pos, size_t count)

{

	struct device *dev;

	struct nvmem_device *nvmem;

	int rc;



	if (attr->private)

		dev = attr->private;

	else

		dev = container_of(kobj, struct device, kobj);

	nvmem = to_nvmem_device(dev);



	/* Stop the user from reading */

	if (pos >= nvmem->size)

		return 0;



	if (count < nvmem->word_size)

		return -EINVAL;



	if (pos + count > nvmem->size)

		count = nvmem->size - pos;



	count = round_down(count, nvmem->word_size);



	rc = nvmem_reg_read(nvmem, pos, buf, count);



	if (rc)

		return rc;



	return count;

}



static ssize_t bin_attr_nvmem_write(struct file *filp, struct kobject *kobj,

				     struct bin_attribute *attr,

				     char *buf, loff_t pos, size_t count)

{

	struct device *dev;

	struct nvmem_device *nvmem;

	int rc;



	if (attr->private)

		dev = attr->private;

	else

		dev = container_of(kobj, struct device, kobj);

	nvmem = to_nvmem_device(dev);



	/* Stop the user from writing */

	if (pos >= nvmem->size)

		return -EFBIG;



	if (count < nvmem->word_size)

		return -EINVAL;



	if (pos + count > nvmem->size)

		count = nvmem->size - pos;



	count = round_down(count, nvmem->word_size);



	rc = nvmem_reg_write(nvmem, pos, buf, count);



	if (rc)

		return rc;



	return count;

}



/* default read/write permissions */

static struct bin_attribute bin_attr_rw_nvmem = {

	.attr	= {

		.name	= "nvmem",

		.mode	= S_IWUSR | S_IRUGO,

	},

	.read	= bin_attr_nvmem_read,

	.write	= bin_attr_nvmem_write,

};



static struct bin_attribute *nvmem_bin_rw_attributes[] = {

	&bin_attr_rw_nvmem,

	NULL,

};



static const struct attribute_group nvmem_bin_rw_group = {

	.bin_attrs	= nvmem_bin_rw_attributes,

};



static const struct attribute_group *nvmem_rw_dev_groups[] = {

	&nvmem_bin_rw_group,

	NULL,

};



/* read only permission */

static struct bin_attribute bin_attr_ro_nvmem = {

	.attr	= {

		.name	= "nvmem",

		.mode	= S_IRUGO,

	},

	.read	= bin_attr_nvmem_read,

};



static struct bin_attribute *nvmem_bin_ro_attributes[] = {

	&bin_attr_ro_nvmem,

	NULL,

};



static const struct attribute_group nvmem_bin_ro_group = {

	.bin_attrs	= nvmem_bin_ro_attributes,

};



static const struct attribute_group *nvmem_ro_dev_groups[] = {

	&nvmem_bin_ro_group,

	NULL,

};



/* default read/write permissions, root only */

static struct bin_attribute bin_attr_rw_root_nvmem = {

	.attr	= {

		.name	= "nvmem",

		.mode	= S_IWUSR | S_IRUSR,

	},

	.read	= bin_attr_nvmem_read,

	.write	= bin_attr_nvmem_write,

};



static struct bin_attribute *nvmem_bin_rw_root_attributes[] = {

	&bin_attr_rw_root_nvmem,

	NULL,

};



static const struct attribute_group nvmem_bin_rw_root_group = {

	.bin_attrs	= nvmem_bin_rw_root_attributes,

};



static const struct attribute_group *nvmem_rw_root_dev_groups[] = {

	&nvmem_bin_rw_root_group,

	NULL,

};



/* read only permission, root only */

static struct bin_attribute bin_attr_ro_root_nvmem = {

	.attr	= {

		.name	= "nvmem",

		.mode	= S_IRUSR,

	},

	.read	= bin_attr_nvmem_read,

};



static struct bin_attribute *nvmem_bin_ro_root_attributes[] = {

	&bin_attr_ro_root_nvmem,

	NULL,

};



static const struct attribute_group nvmem_bin_ro_root_group = {

	.bin_attrs	= nvmem_bin_ro_root_attributes,

};



static const struct attribute_group *nvmem_ro_root_dev_groups[] = {

	&nvmem_bin_ro_root_group,

	NULL,

};



static void nvmem_release(struct device *dev)

{

	struct nvmem_device *nvmem = to_nvmem_device(dev);
@@ -402,43 +217,6 @@ int nvmem_add_cells(struct nvmem_device *nvmem, 
}

EXPORT_SYMBOL_GPL(nvmem_add_cells);



/*

 * nvmem_setup_compat() - Create an additional binary entry in

 * drivers sys directory, to be backwards compatible with the older

 * drivers/misc/eeprom drivers.

 */

static int nvmem_setup_compat(struct nvmem_device *nvmem,

			      const struct nvmem_config *config)

{

	int rval;



	if (!config->base_dev)

		return -EINVAL;



	if (nvmem->read_only)

		nvmem->eeprom = bin_attr_ro_root_nvmem;

	else

		nvmem->eeprom = bin_attr_rw_root_nvmem;

	nvmem->eeprom.attr.name = "eeprom";

	nvmem->eeprom.size = nvmem->size;

#ifdef CONFIG_DEBUG_LOCK_ALLOC

	nvmem->eeprom.attr.key = &eeprom_lock_key;

#endif

	nvmem->eeprom.private = &nvmem->dev;

	nvmem->base_dev = config->base_dev;



	rval = device_create_bin_file(nvmem->base_dev, &nvmem->eeprom);

	if (rval) {

		dev_err(&nvmem->dev,

			"Failed to create eeprom binary file %d\n", rval);

		return rval;

	}



	nvmem->flags |= FLAG_COMPAT;



	return 0;

}



/**

 * nvmem_register() - Register a nvmem device for given nvmem_config.

 * Also creates an binary entry in /sys/bus/nvmem/devices/dev-name/nvmem
@@ -493,14 +271,7 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config) 
	nvmem->read_only = device_property_present(config->dev, "read-only") |

			   config->read_only;



	if (config->root_only)

		nvmem->dev.groups = nvmem->read_only ?

			nvmem_ro_root_dev_groups :

			nvmem_rw_root_dev_groups;

	else

		nvmem->dev.groups = nvmem->read_only ?

			nvmem_ro_dev_groups :

			nvmem_rw_dev_groups;

	nvmem->dev.groups = nvmem_sysfs_get_groups(nvmem, config);



	device_initialize(&nvmem->dev);
@@ -511,7 +282,7 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config) 
		goto err_put_device;



	if (config->compat) {

		rval = nvmem_setup_compat(nvmem, config);

		rval = nvmem_sysfs_setup_compat(nvmem, config);

		if (rval)

			goto err_device_del;

	}
@@ -526,7 +297,7 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config) 


err_teardown_compat:

	if (config->compat)

		device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom);

		nvmem_sysfs_remove_compat(nvmem, config);

err_device_del:

	device_del(&nvmem->dev);

err_put_device:

drivers/nvmem/nvmem-sysfs.c

0 → 100644
+230 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * Copyright (c) 2019, Linaro Limited

 */

#include "nvmem.h"



#ifdef CONFIG_DEBUG_LOCK_ALLOC

static struct lock_class_key eeprom_lock_key;

#endif



static ssize_t bin_attr_nvmem_read(struct file *filp, struct kobject *kobj,

				    struct bin_attribute *attr,

				    char *buf, loff_t pos, size_t count)

{

	struct device *dev;

	struct nvmem_device *nvmem;

	int rc;



	if (attr->private)

		dev = attr->private;

	else

		dev = container_of(kobj, struct device, kobj);

	nvmem = to_nvmem_device(dev);



	/* Stop the user from reading */

	if (pos >= nvmem->size)

		return 0;



	if (count < nvmem->word_size)

		return -EINVAL;



	if (pos + count > nvmem->size)

		count = nvmem->size - pos;



	count = round_down(count, nvmem->word_size);



	rc = nvmem->reg_read(nvmem->priv, pos, buf, count);



	if (rc)

		return rc;



	return count;

}



static ssize_t bin_attr_nvmem_write(struct file *filp, struct kobject *kobj,

				     struct bin_attribute *attr,

				     char *buf, loff_t pos, size_t count)

{

	struct device *dev;

	struct nvmem_device *nvmem;

	int rc;



	if (attr->private)

		dev = attr->private;

	else

		dev = container_of(kobj, struct device, kobj);

	nvmem = to_nvmem_device(dev);



	/* Stop the user from writing */

	if (pos >= nvmem->size)

		return -EFBIG;



	if (count < nvmem->word_size)

		return -EINVAL;



	if (pos + count > nvmem->size)

		count = nvmem->size - pos;



	count = round_down(count, nvmem->word_size);



	rc = nvmem->reg_write(nvmem->priv, pos, buf, count);



	if (rc)

		return rc;



	return count;

}



/* default read/write permissions */

static struct bin_attribute bin_attr_rw_nvmem = {

	.attr	= {

		.name	= "nvmem",

		.mode	= S_IWUSR | S_IRUGO,

	},

	.read	= bin_attr_nvmem_read,

	.write	= bin_attr_nvmem_write,

};



static struct bin_attribute *nvmem_bin_rw_attributes[] = {

	&bin_attr_rw_nvmem,

	NULL,

};



static const struct attribute_group nvmem_bin_rw_group = {

	.bin_attrs	= nvmem_bin_rw_attributes,

};



static const struct attribute_group *nvmem_rw_dev_groups[] = {

	&nvmem_bin_rw_group,

	NULL,

};



/* read only permission */

static struct bin_attribute bin_attr_ro_nvmem = {

	.attr	= {

		.name	= "nvmem",

		.mode	= S_IRUGO,

	},

	.read	= bin_attr_nvmem_read,

};



static struct bin_attribute *nvmem_bin_ro_attributes[] = {

	&bin_attr_ro_nvmem,

	NULL,

};



static const struct attribute_group nvmem_bin_ro_group = {

	.bin_attrs	= nvmem_bin_ro_attributes,

};



static const struct attribute_group *nvmem_ro_dev_groups[] = {

	&nvmem_bin_ro_group,

	NULL,

};



/* default read/write permissions, root only */

static struct bin_attribute bin_attr_rw_root_nvmem = {

	.attr	= {

		.name	= "nvmem",

		.mode	= S_IWUSR | S_IRUSR,

	},

	.read	= bin_attr_nvmem_read,

	.write	= bin_attr_nvmem_write,

};



static struct bin_attribute *nvmem_bin_rw_root_attributes[] = {

	&bin_attr_rw_root_nvmem,

	NULL,

};



static const struct attribute_group nvmem_bin_rw_root_group = {

	.bin_attrs	= nvmem_bin_rw_root_attributes,

};



static const struct attribute_group *nvmem_rw_root_dev_groups[] = {

	&nvmem_bin_rw_root_group,

	NULL,

};



/* read only permission, root only */

static struct bin_attribute bin_attr_ro_root_nvmem = {

	.attr	= {

		.name	= "nvmem",

		.mode	= S_IRUSR,

	},

	.read	= bin_attr_nvmem_read,

};



static struct bin_attribute *nvmem_bin_ro_root_attributes[] = {

	&bin_attr_ro_root_nvmem,

	NULL,

};



static const struct attribute_group nvmem_bin_ro_root_group = {

	.bin_attrs	= nvmem_bin_ro_root_attributes,

};



static const struct attribute_group *nvmem_ro_root_dev_groups[] = {

	&nvmem_bin_ro_root_group,

	NULL,

};



const struct attribute_group **nvmem_sysfs_get_groups(

					struct nvmem_device *nvmem,

					const struct nvmem_config *config)

{

	if (config->root_only)

		return nvmem->read_only ?

			nvmem_ro_root_dev_groups :

			nvmem_rw_root_dev_groups;



	return nvmem->read_only ? nvmem_ro_dev_groups : nvmem_rw_dev_groups;

}



/*

 * nvmem_setup_compat() - Create an additional binary entry in

 * drivers sys directory, to be backwards compatible with the older

 * drivers/misc/eeprom drivers.

 */

int nvmem_sysfs_setup_compat(struct nvmem_device *nvmem,

			      const struct nvmem_config *config)

{

	int rval;



	if (!config->compat)

		return 0;



	if (!config->base_dev)

		return -EINVAL;



	if (nvmem->read_only)

		nvmem->eeprom = bin_attr_ro_root_nvmem;

	else

		nvmem->eeprom = bin_attr_rw_root_nvmem;

	nvmem->eeprom.attr.name = "eeprom";

	nvmem->eeprom.size = nvmem->size;

#ifdef CONFIG_DEBUG_LOCK_ALLOC

	nvmem->eeprom.attr.key = &eeprom_lock_key;

#endif

	nvmem->eeprom.private = &nvmem->dev;

	nvmem->base_dev = config->base_dev;



	rval = device_create_bin_file(nvmem->base_dev, &nvmem->eeprom);

	if (rval) {

		dev_err(&nvmem->dev,

			"Failed to create eeprom binary file %d\n", rval);

		return rval;

	}



	nvmem->flags |= FLAG_COMPAT;



	return 0;

}



void nvmem_sysfs_remove_compat(struct nvmem_device *nvmem,

			      const struct nvmem_config *config)

{

	if (config->compat)

		device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom);

}