drivers/staging/greybus/sysfs.c

/*
 * Greybus sysfs file functions
 *
 * Copyright 2014 Google Inc.
 *
 * Released under the GPLv2 only.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/types.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/kthread.h>
#include <linux/device.h>

#include "greybus.h"
#include "kernel_ver.h"

/* Module fields */
#define gb_module_attr(field)						\
static ssize_t module_##field##_show(struct device *dev,		\
				     struct device_attribute *attr,	\
				     char *buf)				\
{									\
	struct gb_module *gmod = to_gb_module(dev);			\
	return sprintf(buf, "%x\n", gmod->field);			\
}									\
static DEVICE_ATTR_RO(module_##field)

gb_module_attr(vendor);
gb_module_attr(product);
gb_module_attr(version);

static ssize_t module_serial_number_show(struct device *dev,
					 struct device_attribute *attr,
					 char *buf)
{
	struct gb_module *gmod = to_gb_module(dev);

	return sprintf(buf, "%llX\n", (unsigned long long)gmod->unique_id);
}
static DEVICE_ATTR_RO(module_serial_number);

static ssize_t module_vendor_string_show(struct device *dev,
					 struct device_attribute *attr,
					 char *buf)
{
	struct gb_module *gmod = to_gb_module(dev);

	return sprintf(buf, "%s", gmod->vendor_string);
}
static DEVICE_ATTR_RO(module_vendor_string);

static ssize_t module_product_string_show(struct device *dev,
					 struct device_attribute *attr,
					 char *buf)
{
	struct gb_module *gmod = to_gb_module(dev);

	return sprintf(buf, "%s", gmod->product_string);
}
static DEVICE_ATTR_RO(module_product_string);

static struct attribute *module_attrs[] = {
	&dev_attr_module_vendor.attr,
	&dev_attr_module_product.attr,
	&dev_attr_module_version.attr,
	&dev_attr_module_serial_number.attr,
	&dev_attr_module_vendor_string.attr,
	&dev_attr_module_product_string.attr,
	NULL,
};

static umode_t module_attrs_are_visible(struct kobject *kobj,
					struct attribute *a, int n)
{
	struct gb_module *gmod = to_gb_module(kobj_to_dev(kobj));
	umode_t mode = a->mode;

	if (a == &dev_attr_module_vendor_string.attr && gmod->vendor_string)
		return mode;
	if (a == &dev_attr_module_product_string.attr && gmod->product_string)
		return mode;
	if (gmod->vendor || gmod->product || gmod->version)
		return mode;
	if (gmod->unique_id)
		return mode;

	return 0;
}

static struct attribute_group module_attr_grp = {
	.attrs =	module_attrs,
	.is_visible =	module_attrs_are_visible,
};

const struct attribute_group *greybus_module_groups[] = {
	&module_attr_grp,
	NULL,
};