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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 | /* * 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); |