// SPDX-License-Identifier: GPL-2.0/* * Copyright (C) ST-Ericsson SA 2011 * * Author: Lee Jones <lee.jones@linaro.org> for ST-Ericsson. */ #include <linux/sysfs.h>#include <linux/init.h>#include <linux/stat.h>#include <linux/slab.h>#include <linux/idr.h>#include <linux/spinlock.h>#include <linux/sys_soc.h>#include <linux/err.h>#include <linux/glob.h> static DEFINE_IDA(soc_ida); /* Prototype to allow declarations of DEVICE_ATTR(<foo>) before soc_info_show */static ssize_t soc_info_show(struct device *dev, struct device_attribute *attr,			     char *buf); struct soc_device {	struct device dev;	struct soc_device_attribute *attr;	int soc_dev_num;}; static struct bus_type soc_bus_type = {	.name  = "soc",}; static DEVICE_ATTR(machine,		0444, soc_info_show,  NULL);static DEVICE_ATTR(family,		0444, soc_info_show,  NULL);static DEVICE_ATTR(serial_number,	0444, soc_info_show,  NULL);static DEVICE_ATTR(soc_id,		0444, soc_info_show,  NULL);static DEVICE_ATTR(revision,		0444, soc_info_show,  NULL); struct device *soc_device_to_device(struct soc_device *soc_dev){	return &soc_dev->dev;} static umode_t soc_attribute_mode(struct kobject *kobj,				struct attribute *attr,				int index){	struct device *dev = kobj_to_dev(kobj);	struct soc_device *soc_dev = container_of(dev, struct soc_device, dev); 	if ((attr == &dev_attr_machine.attr) && soc_dev->attr->machine)		return attr->mode;	if ((attr == &dev_attr_family.attr) && soc_dev->attr->family)		return attr->mode;	if ((attr == &dev_attr_revision.attr) && soc_dev->attr->revision)		return attr->mode;	if ((attr == &dev_attr_serial_number.attr) && soc_dev->attr->serial_number)		return attr->mode;	if ((attr == &dev_attr_soc_id.attr) && soc_dev->attr->soc_id)		return attr->mode; 	/* Unknown or unfilled attribute */	return 0;} static ssize_t soc_info_show(struct device *dev, struct device_attribute *attr,			     char *buf){	struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);	const char *output; 	if (attr == &dev_attr_machine)		output = soc_dev->attr->machine;	else if (attr == &dev_attr_family)		output = soc_dev->attr->family;	else if (attr == &dev_attr_revision)		output = soc_dev->attr->revision;	else if (attr == &dev_attr_serial_number)		output = soc_dev->attr->serial_number;	else if (attr == &dev_attr_soc_id)		output = soc_dev->attr->soc_id;	else		return -EINVAL; 	return sysfs_emit(buf, "%s\n", output);} static struct attribute *soc_attr[] = {	&dev_attr_machine.attr,	&dev_attr_family.attr,	&dev_attr_serial_number.attr,	&dev_attr_soc_id.attr,	&dev_attr_revision.attr,	NULL,}; static const struct attribute_group soc_attr_group = {	.attrs = soc_attr,	.is_visible = soc_attribute_mode,}; static void soc_release(struct device *dev){	struct soc_device *soc_dev = container_of(dev, struct soc_device, dev); 	ida_simple_remove(&soc_ida, soc_dev->soc_dev_num);	kfree(soc_dev->dev.groups);	kfree(soc_dev);} static struct soc_device_attribute *early_soc_dev_attr; struct soc_device *soc_device_register(struct soc_device_attribute *soc_dev_attr){	struct soc_device *soc_dev;	const struct attribute_group **soc_attr_groups;	int ret; 	if (!soc_bus_type.p) {		if (early_soc_dev_attr)			return ERR_PTR(-EBUSY);		early_soc_dev_attr = soc_dev_attr;		return NULL;	} 	soc_dev = kzalloc(sizeof(*soc_dev), GFP_KERNEL);	if (!soc_dev) {		ret = -ENOMEM;		goto out1;	} 	soc_attr_groups = kcalloc(3, sizeof(*soc_attr_groups), GFP_KERNEL);	if (!soc_attr_groups) {		ret = -ENOMEM;		goto out2;	}	soc_attr_groups[0] = &soc_attr_group;	soc_attr_groups[1] = soc_dev_attr->custom_attr_group; 	/* Fetch a unique (reclaimable) SOC ID. */	ret = ida_simple_get(&soc_ida, 0, 0, GFP_KERNEL);	if (ret < 0)		goto out3;	soc_dev->soc_dev_num = ret; 	soc_dev->attr = soc_dev_attr;	soc_dev->dev.bus = &soc_bus_type;	soc_dev->dev.groups = soc_attr_groups;	soc_dev->dev.release = soc_release; 	dev_set_name(&soc_dev->dev, "soc%d", soc_dev->soc_dev_num); 	ret = device_register(&soc_dev->dev);	if (ret) {		put_device(&soc_dev->dev);		return ERR_PTR(ret);	} 	return soc_dev; out3:	kfree(soc_attr_groups);out2:	kfree(soc_dev);out1:	return ERR_PTR(ret);}EXPORT_SYMBOL_GPL(soc_device_register); /* Ensure soc_dev->attr is freed after calling soc_device_unregister. */void soc_device_unregister(struct soc_device *soc_dev){	device_unregister(&soc_dev->dev);	early_soc_dev_attr = NULL;}EXPORT_SYMBOL_GPL(soc_device_unregister); static int __init soc_bus_register(void){	int ret; 	ret = bus_register(&soc_bus_type);	if (ret)		return ret; 	if (early_soc_dev_attr)		return PTR_ERR(soc_device_register(early_soc_dev_attr)); 	return 0;}core_initcall(soc_bus_register); static int soc_device_match_attr(const struct soc_device_attribute *attr,				 const struct soc_device_attribute *match){	if (match->machine &&	    (!attr->machine || !glob_match(match->machine, attr->machine)))		return 0; 	if (match->family &&	    (!attr->family || !glob_match(match->family, attr->family)))		return 0; 	if (match->revision &&	    (!attr->revision || !glob_match(match->revision, attr->revision)))		return 0; 	if (match->soc_id &&	    (!attr->soc_id || !glob_match(match->soc_id, attr->soc_id)))		return 0; 	return 1;} static int soc_device_match_one(struct device *dev, void *arg){	struct soc_device *soc_dev = container_of(dev, struct soc_device, dev); 	return soc_device_match_attr(soc_dev->attr, arg);} /* * soc_device_match - identify the SoC in the machine * @matches: zero-terminated array of possible matches * * returns the first matching entry of the argument array, or NULL * if none of them match. * * This function is meant as a helper in place of of_match_node() * in cases where either no device tree is available or the information * in a device node is insufficient to identify a particular variant * by its compatible strings or other properties. For new devices, * the DT binding should always provide unique compatible strings * that allow the use of of_match_node() instead. * * The calling function can use the .data entry of the * soc_device_attribute to pass a structure or function pointer for * each entry. */const struct soc_device_attribute *soc_device_match(	const struct soc_device_attribute *matches){	int ret = 0; 	if (!matches)		return NULL; 	while (!ret) {		if (!(matches->machine || matches->family ||		      matches->revision || matches->soc_id))			break;		ret = bus_for_each_dev(&soc_bus_type, NULL, (void *)matches,				       soc_device_match_one);		if (ret < 0 && early_soc_dev_attr)			ret = soc_device_match_attr(early_soc_dev_attr,						    matches);		if (ret < 0)			return NULL;		if (!ret)			matches++;		else			return matches;	}	return NULL;}EXPORT_SYMBOL_GPL(soc_device_match);