1 /* 2 * Copyright (c) 2017 Linaro Ltd. 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 and 6 * only version 2 as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 */ 13 14 #include <linux/kernel.h> 15 #include <linux/cdev.h> 16 #include <linux/err.h> 17 #include <linux/module.h> 18 #include <linux/platform_device.h> 19 #include <linux/of.h> 20 #include <linux/of_reserved_mem.h> 21 #include <linux/dma-mapping.h> 22 #include <linux/slab.h> 23 #include <linux/uaccess.h> 24 #include <linux/io.h> 25 #include <linux/qcom_scm.h> 26 27 #define QCOM_RMTFS_MEM_DEV_MAX (MINORMASK + 1) 28 29 static dev_t qcom_rmtfs_mem_major; 30 31 struct qcom_rmtfs_mem { 32 struct device dev; 33 struct cdev cdev; 34 35 void *base; 36 phys_addr_t addr; 37 phys_addr_t size; 38 39 unsigned int client_id; 40 41 unsigned int perms; 42 }; 43 44 static ssize_t qcom_rmtfs_mem_show(struct device *dev, 45 struct device_attribute *attr, 46 char *buf); 47 48 static DEVICE_ATTR(phys_addr, 0444, qcom_rmtfs_mem_show, NULL); 49 static DEVICE_ATTR(size, 0444, qcom_rmtfs_mem_show, NULL); 50 static DEVICE_ATTR(client_id, 0444, qcom_rmtfs_mem_show, NULL); 51 52 static ssize_t qcom_rmtfs_mem_show(struct device *dev, 53 struct device_attribute *attr, 54 char *buf) 55 { 56 struct qcom_rmtfs_mem *rmtfs_mem = container_of(dev, 57 struct qcom_rmtfs_mem, 58 dev); 59 60 if (attr == &dev_attr_phys_addr) 61 return sprintf(buf, "%pa\n", &rmtfs_mem->addr); 62 if (attr == &dev_attr_size) 63 return sprintf(buf, "%pa\n", &rmtfs_mem->size); 64 if (attr == &dev_attr_client_id) 65 return sprintf(buf, "%d\n", rmtfs_mem->client_id); 66 67 return -EINVAL; 68 } 69 70 static struct attribute *qcom_rmtfs_mem_attrs[] = { 71 &dev_attr_phys_addr.attr, 72 &dev_attr_size.attr, 73 &dev_attr_client_id.attr, 74 NULL 75 }; 76 ATTRIBUTE_GROUPS(qcom_rmtfs_mem); 77 78 static int qcom_rmtfs_mem_open(struct inode *inode, struct file *filp) 79 { 80 struct qcom_rmtfs_mem *rmtfs_mem = container_of(inode->i_cdev, 81 struct qcom_rmtfs_mem, 82 cdev); 83 84 get_device(&rmtfs_mem->dev); 85 filp->private_data = rmtfs_mem; 86 87 return 0; 88 } 89 static ssize_t qcom_rmtfs_mem_read(struct file *filp, 90 char __user *buf, size_t count, loff_t *f_pos) 91 { 92 struct qcom_rmtfs_mem *rmtfs_mem = filp->private_data; 93 94 if (*f_pos >= rmtfs_mem->size) 95 return 0; 96 97 if (*f_pos + count >= rmtfs_mem->size) 98 count = rmtfs_mem->size - *f_pos; 99 100 if (copy_to_user(buf, rmtfs_mem->base + *f_pos, count)) 101 return -EFAULT; 102 103 *f_pos += count; 104 return count; 105 } 106 107 static ssize_t qcom_rmtfs_mem_write(struct file *filp, 108 const char __user *buf, size_t count, 109 loff_t *f_pos) 110 { 111 struct qcom_rmtfs_mem *rmtfs_mem = filp->private_data; 112 113 if (*f_pos >= rmtfs_mem->size) 114 return 0; 115 116 if (*f_pos + count >= rmtfs_mem->size) 117 count = rmtfs_mem->size - *f_pos; 118 119 if (copy_from_user(rmtfs_mem->base + *f_pos, buf, count)) 120 return -EFAULT; 121 122 *f_pos += count; 123 return count; 124 } 125 126 static int qcom_rmtfs_mem_release(struct inode *inode, struct file *filp) 127 { 128 struct qcom_rmtfs_mem *rmtfs_mem = filp->private_data; 129 130 put_device(&rmtfs_mem->dev); 131 132 return 0; 133 } 134 135 static struct class rmtfs_class = { 136 .owner = THIS_MODULE, 137 .name = "rmtfs", 138 }; 139 140 static const struct file_operations qcom_rmtfs_mem_fops = { 141 .owner = THIS_MODULE, 142 .open = qcom_rmtfs_mem_open, 143 .read = qcom_rmtfs_mem_read, 144 .write = qcom_rmtfs_mem_write, 145 .release = qcom_rmtfs_mem_release, 146 .llseek = default_llseek, 147 }; 148 149 static void qcom_rmtfs_mem_release_device(struct device *dev) 150 { 151 struct qcom_rmtfs_mem *rmtfs_mem = container_of(dev, 152 struct qcom_rmtfs_mem, 153 dev); 154 155 kfree(rmtfs_mem); 156 } 157 158 static int qcom_rmtfs_mem_probe(struct platform_device *pdev) 159 { 160 struct device_node *node = pdev->dev.of_node; 161 struct qcom_scm_vmperm perms[2]; 162 struct reserved_mem *rmem; 163 struct qcom_rmtfs_mem *rmtfs_mem; 164 u32 client_id; 165 u32 vmid; 166 int ret; 167 168 rmem = of_reserved_mem_lookup(node); 169 if (!rmem) { 170 dev_err(&pdev->dev, "failed to acquire memory region\n"); 171 return -EINVAL; 172 } 173 174 ret = of_property_read_u32(node, "qcom,client-id", &client_id); 175 if (ret) { 176 dev_err(&pdev->dev, "failed to parse \"qcom,client-id\"\n"); 177 return ret; 178 179 } 180 181 rmtfs_mem = kzalloc(sizeof(*rmtfs_mem), GFP_KERNEL); 182 if (!rmtfs_mem) 183 return -ENOMEM; 184 185 rmtfs_mem->addr = rmem->base; 186 rmtfs_mem->client_id = client_id; 187 rmtfs_mem->size = rmem->size; 188 189 device_initialize(&rmtfs_mem->dev); 190 rmtfs_mem->dev.parent = &pdev->dev; 191 rmtfs_mem->dev.groups = qcom_rmtfs_mem_groups; 192 rmtfs_mem->dev.release = qcom_rmtfs_mem_release_device; 193 194 rmtfs_mem->base = devm_memremap(&rmtfs_mem->dev, rmtfs_mem->addr, 195 rmtfs_mem->size, MEMREMAP_WC); 196 if (IS_ERR(rmtfs_mem->base)) { 197 dev_err(&pdev->dev, "failed to remap rmtfs_mem region\n"); 198 ret = PTR_ERR(rmtfs_mem->base); 199 goto put_device; 200 } 201 202 cdev_init(&rmtfs_mem->cdev, &qcom_rmtfs_mem_fops); 203 rmtfs_mem->cdev.owner = THIS_MODULE; 204 205 dev_set_name(&rmtfs_mem->dev, "qcom_rmtfs_mem%d", client_id); 206 rmtfs_mem->dev.id = client_id; 207 rmtfs_mem->dev.class = &rmtfs_class; 208 rmtfs_mem->dev.devt = MKDEV(MAJOR(qcom_rmtfs_mem_major), client_id); 209 210 ret = cdev_device_add(&rmtfs_mem->cdev, &rmtfs_mem->dev); 211 if (ret) { 212 dev_err(&pdev->dev, "failed to add cdev: %d\n", ret); 213 goto put_device; 214 } 215 216 ret = of_property_read_u32(node, "qcom,vmid", &vmid); 217 if (ret < 0 && ret != -EINVAL) { 218 dev_err(&pdev->dev, "failed to parse qcom,vmid\n"); 219 goto remove_cdev; 220 } else if (!ret) { 221 if (!qcom_scm_is_available()) { 222 ret = -EPROBE_DEFER; 223 goto remove_cdev; 224 } 225 226 perms[0].vmid = QCOM_SCM_VMID_HLOS; 227 perms[0].perm = QCOM_SCM_PERM_RW; 228 perms[1].vmid = vmid; 229 perms[1].perm = QCOM_SCM_PERM_RW; 230 231 rmtfs_mem->perms = BIT(QCOM_SCM_VMID_HLOS); 232 ret = qcom_scm_assign_mem(rmtfs_mem->addr, rmtfs_mem->size, 233 &rmtfs_mem->perms, perms, 2); 234 if (ret < 0) { 235 dev_err(&pdev->dev, "assign memory failed\n"); 236 goto remove_cdev; 237 } 238 } 239 240 dev_set_drvdata(&pdev->dev, rmtfs_mem); 241 242 return 0; 243 244 remove_cdev: 245 cdev_device_del(&rmtfs_mem->cdev, &rmtfs_mem->dev); 246 put_device: 247 put_device(&rmtfs_mem->dev); 248 249 return ret; 250 } 251 252 static int qcom_rmtfs_mem_remove(struct platform_device *pdev) 253 { 254 struct qcom_rmtfs_mem *rmtfs_mem = dev_get_drvdata(&pdev->dev); 255 struct qcom_scm_vmperm perm; 256 257 if (rmtfs_mem->perms) { 258 perm.vmid = QCOM_SCM_VMID_HLOS; 259 perm.perm = QCOM_SCM_PERM_RW; 260 261 qcom_scm_assign_mem(rmtfs_mem->addr, rmtfs_mem->size, 262 &rmtfs_mem->perms, &perm, 1); 263 } 264 265 cdev_device_del(&rmtfs_mem->cdev, &rmtfs_mem->dev); 266 put_device(&rmtfs_mem->dev); 267 268 return 0; 269 } 270 271 static const struct of_device_id qcom_rmtfs_mem_of_match[] = { 272 { .compatible = "qcom,rmtfs-mem" }, 273 {} 274 }; 275 MODULE_DEVICE_TABLE(of, qcom_rmtfs_mem_of_match); 276 277 static struct platform_driver qcom_rmtfs_mem_driver = { 278 .probe = qcom_rmtfs_mem_probe, 279 .remove = qcom_rmtfs_mem_remove, 280 .driver = { 281 .name = "qcom_rmtfs_mem", 282 .of_match_table = qcom_rmtfs_mem_of_match, 283 }, 284 }; 285 286 static int __init qcom_rmtfs_mem_init(void) 287 { 288 int ret; 289 290 ret = class_register(&rmtfs_class); 291 if (ret) 292 return ret; 293 294 ret = alloc_chrdev_region(&qcom_rmtfs_mem_major, 0, 295 QCOM_RMTFS_MEM_DEV_MAX, "qcom_rmtfs_mem"); 296 if (ret < 0) { 297 pr_err("qcom_rmtfs_mem: failed to allocate char dev region\n"); 298 goto unregister_class; 299 } 300 301 ret = platform_driver_register(&qcom_rmtfs_mem_driver); 302 if (ret < 0) { 303 pr_err("qcom_rmtfs_mem: failed to register rmtfs_mem driver\n"); 304 goto unregister_chrdev; 305 } 306 307 return 0; 308 309 unregister_chrdev: 310 unregister_chrdev_region(qcom_rmtfs_mem_major, QCOM_RMTFS_MEM_DEV_MAX); 311 unregister_class: 312 class_unregister(&rmtfs_class); 313 return ret; 314 } 315 module_init(qcom_rmtfs_mem_init); 316 317 static void __exit qcom_rmtfs_mem_exit(void) 318 { 319 platform_driver_unregister(&qcom_rmtfs_mem_driver); 320 unregister_chrdev_region(qcom_rmtfs_mem_major, QCOM_RMTFS_MEM_DEV_MAX); 321 class_unregister(&rmtfs_class); 322 } 323 module_exit(qcom_rmtfs_mem_exit); 324 325 MODULE_AUTHOR("Linaro Ltd"); 326 MODULE_DESCRIPTION("Qualcomm Remote Filesystem memory driver"); 327 MODULE_LICENSE("GPL v2"); 328