/* * Copyright (C) ST-Ericsson SA 2011 * * Author: Lee Jones <lee.jones@linaro.org> for ST-Ericsson. * License terms: GNU General Public License (GPL), version 2 */ #include <linux/sysfs.h> #include <linux/module.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> static DEFINE_IDA(soc_ida); static DEFINE_SPINLOCK(soc_lock); static ssize_t soc_info_get(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, S_IRUGO, soc_info_get, NULL); static DEVICE_ATTR(family, S_IRUGO, soc_info_get, NULL); static DEVICE_ATTR(soc_id, S_IRUGO, soc_info_get, NULL); static DEVICE_ATTR(revision, S_IRUGO, soc_info_get, 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 = container_of(kobj, struct device, kobj); struct soc_device *soc_dev = container_of(dev, struct soc_device, dev); if ((attr == &dev_attr_machine.attr) && (soc_dev->attr->machine != NULL)) return attr->mode; if ((attr == &dev_attr_family.attr) && (soc_dev->attr->family != NULL)) return attr->mode; if ((attr == &dev_attr_revision.attr) && (soc_dev->attr->revision != NULL)) return attr->mode; if ((attr == &dev_attr_soc_id.attr) && (soc_dev->attr->soc_id != NULL)) return attr->mode; /* Unknown or unfilled attribute. */ return 0; } static ssize_t soc_info_get(struct device *dev, struct device_attribute *attr, char *buf) { struct soc_device *soc_dev = container_of(dev, struct soc_device, dev); if (attr == &dev_attr_machine) return sprintf(buf, "%s\n", soc_dev->attr->machine); if (attr == &dev_attr_family) return sprintf(buf, "%s\n", soc_dev->attr->family); if (attr == &dev_attr_revision) return sprintf(buf, "%s\n", soc_dev->attr->revision); if (attr == &dev_attr_soc_id) return sprintf(buf, "%s\n", soc_dev->attr->soc_id); return -EINVAL; } static struct attribute *soc_attr[] = { &dev_attr_machine.attr, &dev_attr_family.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 const struct attribute_group *soc_attr_groups[] = { &soc_attr_group, NULL, }; static void soc_release(struct device *dev) { struct soc_device *soc_dev = container_of(dev, struct soc_device, dev); kfree(soc_dev); } struct soc_device *soc_device_register(struct soc_device_attribute *soc_dev_attr) { struct soc_device *soc_dev; int ret; soc_dev = kzalloc(sizeof(*soc_dev), GFP_KERNEL); if (!soc_dev) { ret = -ENOMEM; goto out1; } /* Fetch a unique (reclaimable) SOC ID. */ do { if (!ida_pre_get(&soc_ida, GFP_KERNEL)) { ret = -ENOMEM; goto out2; } spin_lock(&soc_lock); ret = ida_get_new(&soc_ida, &soc_dev->soc_dev_num); spin_unlock(&soc_lock); } while (ret == -EAGAIN); if (ret) goto out2; 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) goto out3; return soc_dev; out3: ida_remove(&soc_ida, soc_dev->soc_dev_num); out2: kfree(soc_dev); out1: return ERR_PTR(ret); } /* Ensure soc_dev->attr is freed prior to calling soc_device_unregister. */ void soc_device_unregister(struct soc_device *soc_dev) { ida_remove(&soc_ida, soc_dev->soc_dev_num); device_unregister(&soc_dev->dev); } static int __init soc_bus_register(void) { return bus_register(&soc_bus_type); } core_initcall(soc_bus_register); static void __exit soc_bus_unregister(void) { ida_destroy(&soc_ida); bus_unregister(&soc_bus_type); } module_exit(soc_bus_unregister);