1 /* 2 * Copyright (C) ST-Ericsson SA 2011 3 * 4 * Author: Lee Jones <lee.jones@linaro.org> for ST-Ericsson. 5 * License terms: GNU General Public License (GPL), version 2 6 */ 7 8 #include <linux/sysfs.h> 9 #include <linux/init.h> 10 #include <linux/stat.h> 11 #include <linux/slab.h> 12 #include <linux/idr.h> 13 #include <linux/spinlock.h> 14 #include <linux/sys_soc.h> 15 #include <linux/err.h> 16 #include <linux/glob.h> 17 18 static DEFINE_IDA(soc_ida); 19 20 static ssize_t soc_info_get(struct device *dev, 21 struct device_attribute *attr, 22 char *buf); 23 24 struct soc_device { 25 struct device dev; 26 struct soc_device_attribute *attr; 27 int soc_dev_num; 28 }; 29 30 static struct bus_type soc_bus_type = { 31 .name = "soc", 32 }; 33 34 static DEVICE_ATTR(machine, S_IRUGO, soc_info_get, NULL); 35 static DEVICE_ATTR(family, S_IRUGO, soc_info_get, NULL); 36 static DEVICE_ATTR(soc_id, S_IRUGO, soc_info_get, NULL); 37 static DEVICE_ATTR(revision, S_IRUGO, soc_info_get, NULL); 38 39 struct device *soc_device_to_device(struct soc_device *soc_dev) 40 { 41 return &soc_dev->dev; 42 } 43 44 static umode_t soc_attribute_mode(struct kobject *kobj, 45 struct attribute *attr, 46 int index) 47 { 48 struct device *dev = container_of(kobj, struct device, kobj); 49 struct soc_device *soc_dev = container_of(dev, struct soc_device, dev); 50 51 if ((attr == &dev_attr_machine.attr) 52 && (soc_dev->attr->machine != NULL)) 53 return attr->mode; 54 if ((attr == &dev_attr_family.attr) 55 && (soc_dev->attr->family != NULL)) 56 return attr->mode; 57 if ((attr == &dev_attr_revision.attr) 58 && (soc_dev->attr->revision != NULL)) 59 return attr->mode; 60 if ((attr == &dev_attr_soc_id.attr) 61 && (soc_dev->attr->soc_id != NULL)) 62 return attr->mode; 63 64 /* Unknown or unfilled attribute. */ 65 return 0; 66 } 67 68 static ssize_t soc_info_get(struct device *dev, 69 struct device_attribute *attr, 70 char *buf) 71 { 72 struct soc_device *soc_dev = container_of(dev, struct soc_device, dev); 73 74 if (attr == &dev_attr_machine) 75 return sprintf(buf, "%s\n", soc_dev->attr->machine); 76 if (attr == &dev_attr_family) 77 return sprintf(buf, "%s\n", soc_dev->attr->family); 78 if (attr == &dev_attr_revision) 79 return sprintf(buf, "%s\n", soc_dev->attr->revision); 80 if (attr == &dev_attr_soc_id) 81 return sprintf(buf, "%s\n", soc_dev->attr->soc_id); 82 83 return -EINVAL; 84 85 } 86 87 static struct attribute *soc_attr[] = { 88 &dev_attr_machine.attr, 89 &dev_attr_family.attr, 90 &dev_attr_soc_id.attr, 91 &dev_attr_revision.attr, 92 NULL, 93 }; 94 95 static const struct attribute_group soc_attr_group = { 96 .attrs = soc_attr, 97 .is_visible = soc_attribute_mode, 98 }; 99 100 static const struct attribute_group *soc_attr_groups[] = { 101 &soc_attr_group, 102 NULL, 103 }; 104 105 static void soc_release(struct device *dev) 106 { 107 struct soc_device *soc_dev = container_of(dev, struct soc_device, dev); 108 109 kfree(soc_dev); 110 } 111 112 struct soc_device *soc_device_register(struct soc_device_attribute *soc_dev_attr) 113 { 114 struct soc_device *soc_dev; 115 int ret; 116 117 if (!soc_bus_type.p) { 118 ret = bus_register(&soc_bus_type); 119 if (ret) 120 goto out1; 121 } 122 123 soc_dev = kzalloc(sizeof(*soc_dev), GFP_KERNEL); 124 if (!soc_dev) { 125 ret = -ENOMEM; 126 goto out1; 127 } 128 129 /* Fetch a unique (reclaimable) SOC ID. */ 130 ret = ida_simple_get(&soc_ida, 0, 0, GFP_KERNEL); 131 if (ret < 0) 132 goto out2; 133 soc_dev->soc_dev_num = ret; 134 135 soc_dev->attr = soc_dev_attr; 136 soc_dev->dev.bus = &soc_bus_type; 137 soc_dev->dev.groups = soc_attr_groups; 138 soc_dev->dev.release = soc_release; 139 140 dev_set_name(&soc_dev->dev, "soc%d", soc_dev->soc_dev_num); 141 142 ret = device_register(&soc_dev->dev); 143 if (ret) 144 goto out3; 145 146 return soc_dev; 147 148 out3: 149 ida_simple_remove(&soc_ida, soc_dev->soc_dev_num); 150 out2: 151 kfree(soc_dev); 152 out1: 153 return ERR_PTR(ret); 154 } 155 156 /* Ensure soc_dev->attr is freed prior to calling soc_device_unregister. */ 157 void soc_device_unregister(struct soc_device *soc_dev) 158 { 159 ida_simple_remove(&soc_ida, soc_dev->soc_dev_num); 160 161 device_unregister(&soc_dev->dev); 162 } 163 164 static int __init soc_bus_register(void) 165 { 166 if (soc_bus_type.p) 167 return 0; 168 169 return bus_register(&soc_bus_type); 170 } 171 core_initcall(soc_bus_register); 172 173 static int soc_device_match_one(struct device *dev, void *arg) 174 { 175 struct soc_device *soc_dev = container_of(dev, struct soc_device, dev); 176 const struct soc_device_attribute *match = arg; 177 178 if (match->machine && 179 (!soc_dev->attr->machine || 180 !glob_match(match->machine, soc_dev->attr->machine))) 181 return 0; 182 183 if (match->family && 184 (!soc_dev->attr->family || 185 !glob_match(match->family, soc_dev->attr->family))) 186 return 0; 187 188 if (match->revision && 189 (!soc_dev->attr->revision || 190 !glob_match(match->revision, soc_dev->attr->revision))) 191 return 0; 192 193 if (match->soc_id && 194 (!soc_dev->attr->soc_id || 195 !glob_match(match->soc_id, soc_dev->attr->soc_id))) 196 return 0; 197 198 return 1; 199 } 200 201 /* 202 * soc_device_match - identify the SoC in the machine 203 * @matches: zero-terminated array of possible matches 204 * 205 * returns the first matching entry of the argument array, or NULL 206 * if none of them match. 207 * 208 * This function is meant as a helper in place of of_match_node() 209 * in cases where either no device tree is available or the information 210 * in a device node is insufficient to identify a particular variant 211 * by its compatible strings or other properties. For new devices, 212 * the DT binding should always provide unique compatible strings 213 * that allow the use of of_match_node() instead. 214 * 215 * The calling function can use the .data entry of the 216 * soc_device_attribute to pass a structure or function pointer for 217 * each entry. 218 */ 219 const struct soc_device_attribute *soc_device_match( 220 const struct soc_device_attribute *matches) 221 { 222 int ret = 0; 223 224 if (!matches) 225 return NULL; 226 227 while (!ret) { 228 if (!(matches->machine || matches->family || 229 matches->revision || matches->soc_id)) 230 break; 231 ret = bus_for_each_dev(&soc_bus_type, NULL, (void *)matches, 232 soc_device_match_one); 233 if (!ret) 234 matches++; 235 else 236 return matches; 237 } 238 return NULL; 239 } 240 EXPORT_SYMBOL_GPL(soc_device_match); 241