1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) ST-Ericsson SA 2011 4 * 5 * Author: Lee Jones <lee.jones@linaro.org> for ST-Ericsson. 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(serial_number, S_IRUGO, soc_info_get, NULL); 37 static DEVICE_ATTR(soc_id, S_IRUGO, soc_info_get, NULL); 38 static DEVICE_ATTR(revision, S_IRUGO, soc_info_get, NULL); 39 40 struct device *soc_device_to_device(struct soc_device *soc_dev) 41 { 42 return &soc_dev->dev; 43 } 44 45 static umode_t soc_attribute_mode(struct kobject *kobj, 46 struct attribute *attr, 47 int index) 48 { 49 struct device *dev = container_of(kobj, struct device, kobj); 50 struct soc_device *soc_dev = container_of(dev, struct soc_device, dev); 51 52 if ((attr == &dev_attr_machine.attr) 53 && (soc_dev->attr->machine != NULL)) 54 return attr->mode; 55 if ((attr == &dev_attr_family.attr) 56 && (soc_dev->attr->family != NULL)) 57 return attr->mode; 58 if ((attr == &dev_attr_revision.attr) 59 && (soc_dev->attr->revision != NULL)) 60 return attr->mode; 61 if ((attr == &dev_attr_serial_number.attr) 62 && (soc_dev->attr->serial_number != NULL)) 63 return attr->mode; 64 if ((attr == &dev_attr_soc_id.attr) 65 && (soc_dev->attr->soc_id != NULL)) 66 return attr->mode; 67 68 /* Unknown or unfilled attribute. */ 69 return 0; 70 } 71 72 static ssize_t soc_info_get(struct device *dev, 73 struct device_attribute *attr, 74 char *buf) 75 { 76 struct soc_device *soc_dev = container_of(dev, struct soc_device, dev); 77 78 if (attr == &dev_attr_machine) 79 return sprintf(buf, "%s\n", soc_dev->attr->machine); 80 if (attr == &dev_attr_family) 81 return sprintf(buf, "%s\n", soc_dev->attr->family); 82 if (attr == &dev_attr_revision) 83 return sprintf(buf, "%s\n", soc_dev->attr->revision); 84 if (attr == &dev_attr_serial_number) 85 return sprintf(buf, "%s\n", soc_dev->attr->serial_number); 86 if (attr == &dev_attr_soc_id) 87 return sprintf(buf, "%s\n", soc_dev->attr->soc_id); 88 89 return -EINVAL; 90 91 } 92 93 static struct attribute *soc_attr[] = { 94 &dev_attr_machine.attr, 95 &dev_attr_family.attr, 96 &dev_attr_serial_number.attr, 97 &dev_attr_soc_id.attr, 98 &dev_attr_revision.attr, 99 NULL, 100 }; 101 102 static const struct attribute_group soc_attr_group = { 103 .attrs = soc_attr, 104 .is_visible = soc_attribute_mode, 105 }; 106 107 static const struct attribute_group *soc_attr_groups[] = { 108 &soc_attr_group, 109 NULL, 110 }; 111 112 static void soc_release(struct device *dev) 113 { 114 struct soc_device *soc_dev = container_of(dev, struct soc_device, dev); 115 116 kfree(soc_dev); 117 } 118 119 static struct soc_device_attribute *early_soc_dev_attr; 120 121 struct soc_device *soc_device_register(struct soc_device_attribute *soc_dev_attr) 122 { 123 struct soc_device *soc_dev; 124 int ret; 125 126 if (!soc_bus_type.p) { 127 if (early_soc_dev_attr) 128 return ERR_PTR(-EBUSY); 129 early_soc_dev_attr = soc_dev_attr; 130 return NULL; 131 } 132 133 soc_dev = kzalloc(sizeof(*soc_dev), GFP_KERNEL); 134 if (!soc_dev) { 135 ret = -ENOMEM; 136 goto out1; 137 } 138 139 /* Fetch a unique (reclaimable) SOC ID. */ 140 ret = ida_simple_get(&soc_ida, 0, 0, GFP_KERNEL); 141 if (ret < 0) 142 goto out2; 143 soc_dev->soc_dev_num = ret; 144 145 soc_dev->attr = soc_dev_attr; 146 soc_dev->dev.bus = &soc_bus_type; 147 soc_dev->dev.groups = soc_attr_groups; 148 soc_dev->dev.release = soc_release; 149 150 dev_set_name(&soc_dev->dev, "soc%d", soc_dev->soc_dev_num); 151 152 ret = device_register(&soc_dev->dev); 153 if (ret) 154 goto out3; 155 156 return soc_dev; 157 158 out3: 159 ida_simple_remove(&soc_ida, soc_dev->soc_dev_num); 160 put_device(&soc_dev->dev); 161 soc_dev = NULL; 162 out2: 163 kfree(soc_dev); 164 out1: 165 return ERR_PTR(ret); 166 } 167 168 /* Ensure soc_dev->attr is freed prior to calling soc_device_unregister. */ 169 void soc_device_unregister(struct soc_device *soc_dev) 170 { 171 ida_simple_remove(&soc_ida, soc_dev->soc_dev_num); 172 173 device_unregister(&soc_dev->dev); 174 early_soc_dev_attr = NULL; 175 } 176 177 static int __init soc_bus_register(void) 178 { 179 int ret; 180 181 ret = bus_register(&soc_bus_type); 182 if (ret) 183 return ret; 184 185 if (early_soc_dev_attr) 186 return PTR_ERR(soc_device_register(early_soc_dev_attr)); 187 188 return 0; 189 } 190 core_initcall(soc_bus_register); 191 192 static int soc_device_match_attr(const struct soc_device_attribute *attr, 193 const struct soc_device_attribute *match) 194 { 195 if (match->machine && 196 (!attr->machine || !glob_match(match->machine, attr->machine))) 197 return 0; 198 199 if (match->family && 200 (!attr->family || !glob_match(match->family, attr->family))) 201 return 0; 202 203 if (match->revision && 204 (!attr->revision || !glob_match(match->revision, attr->revision))) 205 return 0; 206 207 if (match->soc_id && 208 (!attr->soc_id || !glob_match(match->soc_id, attr->soc_id))) 209 return 0; 210 211 return 1; 212 } 213 214 static int soc_device_match_one(struct device *dev, void *arg) 215 { 216 struct soc_device *soc_dev = container_of(dev, struct soc_device, dev); 217 218 return soc_device_match_attr(soc_dev->attr, arg); 219 } 220 221 /* 222 * soc_device_match - identify the SoC in the machine 223 * @matches: zero-terminated array of possible matches 224 * 225 * returns the first matching entry of the argument array, or NULL 226 * if none of them match. 227 * 228 * This function is meant as a helper in place of of_match_node() 229 * in cases where either no device tree is available or the information 230 * in a device node is insufficient to identify a particular variant 231 * by its compatible strings or other properties. For new devices, 232 * the DT binding should always provide unique compatible strings 233 * that allow the use of of_match_node() instead. 234 * 235 * The calling function can use the .data entry of the 236 * soc_device_attribute to pass a structure or function pointer for 237 * each entry. 238 */ 239 const struct soc_device_attribute *soc_device_match( 240 const struct soc_device_attribute *matches) 241 { 242 int ret = 0; 243 244 if (!matches) 245 return NULL; 246 247 while (!ret) { 248 if (!(matches->machine || matches->family || 249 matches->revision || matches->soc_id)) 250 break; 251 ret = bus_for_each_dev(&soc_bus_type, NULL, (void *)matches, 252 soc_device_match_one); 253 if (ret < 0 && early_soc_dev_attr) 254 ret = soc_device_match_attr(early_soc_dev_attr, 255 matches); 256 if (ret < 0) 257 return NULL; 258 if (!ret) 259 matches++; 260 else 261 return matches; 262 } 263 return NULL; 264 } 265 EXPORT_SYMBOL_GPL(soc_device_match); 266