1// SPDX-License-Identifier: GPL-2.0 2// 3// Copyright 2019 Google LLC. 4 5#include <linux/kernel.h> 6#include <linux/module.h> 7#include <linux/of.h> 8#include <linux/platform_device.h> 9#include <linux/remoteproc.h> 10#include <linux/rpmsg/mtk_rpmsg.h> 11#include <linux/slab.h> 12#include <linux/workqueue.h> 13 14#include "rpmsg_internal.h" 15 16struct mtk_rpmsg_rproc_subdev { 17 struct platform_device *pdev; 18 struct mtk_rpmsg_info *info; 19 struct rpmsg_endpoint *ns_ept; 20 struct rproc_subdev subdev; 21 22 struct work_struct register_work; 23 struct list_head channels; 24 struct mutex channels_lock; 25}; 26 27#define to_mtk_subdev(d) container_of(d, struct mtk_rpmsg_rproc_subdev, subdev) 28 29struct mtk_rpmsg_channel_info { 30 struct rpmsg_channel_info info; 31 bool registered; 32 struct list_head list; 33}; 34 35/** 36 * struct rpmsg_ns_msg - dynamic name service announcement message 37 * @name: name of remote service that is published 38 * @addr: address of remote service that is published 39 * 40 * This message is sent across to publish a new service. When we receive these 41 * messages, an appropriate rpmsg channel (i.e device) is created. In turn, the 42 * ->probe() handler of the appropriate rpmsg driver will be invoked 43 * (if/as-soon-as one is registered). 44 */ 45struct rpmsg_ns_msg { 46 char name[RPMSG_NAME_SIZE]; 47 u32 addr; 48} __packed; 49 50struct mtk_rpmsg_device { 51 struct rpmsg_device rpdev; 52 struct mtk_rpmsg_rproc_subdev *mtk_subdev; 53}; 54 55struct mtk_rpmsg_endpoint { 56 struct rpmsg_endpoint ept; 57 struct mtk_rpmsg_rproc_subdev *mtk_subdev; 58}; 59 60#define to_mtk_rpmsg_device(r) container_of(r, struct mtk_rpmsg_device, rpdev) 61#define to_mtk_rpmsg_endpoint(r) container_of(r, struct mtk_rpmsg_endpoint, ept) 62 63static const struct rpmsg_endpoint_ops mtk_rpmsg_endpoint_ops; 64 65static void __mtk_ept_release(struct kref *kref) 66{ 67 struct rpmsg_endpoint *ept = container_of(kref, struct rpmsg_endpoint, 68 refcount); 69 kfree(to_mtk_rpmsg_endpoint(ept)); 70} 71 72static void mtk_rpmsg_ipi_handler(void *data, unsigned int len, void *priv) 73{ 74 struct mtk_rpmsg_endpoint *mept = priv; 75 struct rpmsg_endpoint *ept = &mept->ept; 76 int ret; 77 78 ret = (*ept->cb)(ept->rpdev, data, len, ept->priv, ept->addr); 79 if (ret) 80 dev_warn(&ept->rpdev->dev, "rpmsg handler return error = %d", 81 ret); 82} 83 84static struct rpmsg_endpoint * 85__mtk_create_ept(struct mtk_rpmsg_rproc_subdev *mtk_subdev, 86 struct rpmsg_device *rpdev, rpmsg_rx_cb_t cb, void *priv, 87 u32 id) 88{ 89 struct mtk_rpmsg_endpoint *mept; 90 struct rpmsg_endpoint *ept; 91 struct platform_device *pdev = mtk_subdev->pdev; 92 int ret; 93 94 mept = kzalloc(sizeof(*mept), GFP_KERNEL); 95 if (!mept) 96 return NULL; 97 mept->mtk_subdev = mtk_subdev; 98 99 ept = &mept->ept; 100 kref_init(&ept->refcount); 101 102 ept->rpdev = rpdev; 103 ept->cb = cb; 104 ept->priv = priv; 105 ept->ops = &mtk_rpmsg_endpoint_ops; 106 ept->addr = id; 107 108 ret = mtk_subdev->info->register_ipi(pdev, id, mtk_rpmsg_ipi_handler, 109 mept); 110 if (ret) { 111 dev_err(&pdev->dev, "IPI register failed, id = %d", id); 112 kref_put(&ept->refcount, __mtk_ept_release); 113 return NULL; 114 } 115 116 return ept; 117} 118 119static struct rpmsg_endpoint * 120mtk_rpmsg_create_ept(struct rpmsg_device *rpdev, rpmsg_rx_cb_t cb, void *priv, 121 struct rpmsg_channel_info chinfo) 122{ 123 struct mtk_rpmsg_rproc_subdev *mtk_subdev = 124 to_mtk_rpmsg_device(rpdev)->mtk_subdev; 125 126 return __mtk_create_ept(mtk_subdev, rpdev, cb, priv, chinfo.src); 127} 128 129static void mtk_rpmsg_destroy_ept(struct rpmsg_endpoint *ept) 130{ 131 struct mtk_rpmsg_rproc_subdev *mtk_subdev = 132 to_mtk_rpmsg_endpoint(ept)->mtk_subdev; 133 134 mtk_subdev->info->unregister_ipi(mtk_subdev->pdev, ept->addr); 135 kref_put(&ept->refcount, __mtk_ept_release); 136} 137 138static int mtk_rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len) 139{ 140 struct mtk_rpmsg_rproc_subdev *mtk_subdev = 141 to_mtk_rpmsg_endpoint(ept)->mtk_subdev; 142 143 return mtk_subdev->info->send_ipi(mtk_subdev->pdev, ept->addr, data, 144 len, 0); 145} 146 147static int mtk_rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len) 148{ 149 struct mtk_rpmsg_rproc_subdev *mtk_subdev = 150 to_mtk_rpmsg_endpoint(ept)->mtk_subdev; 151 152 /* 153 * TODO: This currently is same as mtk_rpmsg_send, and wait until SCP 154 * received the last command. 155 */ 156 return mtk_subdev->info->send_ipi(mtk_subdev->pdev, ept->addr, data, 157 len, 0); 158} 159 160static const struct rpmsg_endpoint_ops mtk_rpmsg_endpoint_ops = { 161 .destroy_ept = mtk_rpmsg_destroy_ept, 162 .send = mtk_rpmsg_send, 163 .trysend = mtk_rpmsg_trysend, 164}; 165 166static void mtk_rpmsg_release_device(struct device *dev) 167{ 168 struct rpmsg_device *rpdev = to_rpmsg_device(dev); 169 struct mtk_rpmsg_device *mdev = to_mtk_rpmsg_device(rpdev); 170 171 kfree(mdev); 172} 173 174static const struct rpmsg_device_ops mtk_rpmsg_device_ops = { 175 .create_ept = mtk_rpmsg_create_ept, 176}; 177 178static struct device_node * 179mtk_rpmsg_match_device_subnode(struct device_node *node, const char *channel) 180{ 181 struct device_node *child; 182 const char *name; 183 int ret; 184 185 for_each_available_child_of_node(node, child) { 186 ret = of_property_read_string(child, "mediatek,rpmsg-name", &name); 187 if (ret) 188 continue; 189 190 if (strcmp(name, channel) == 0) 191 return child; 192 } 193 194 return NULL; 195} 196 197static int mtk_rpmsg_register_device(struct mtk_rpmsg_rproc_subdev *mtk_subdev, 198 struct rpmsg_channel_info *info) 199{ 200 struct rpmsg_device *rpdev; 201 struct mtk_rpmsg_device *mdev; 202 struct platform_device *pdev = mtk_subdev->pdev; 203 204 mdev = kzalloc(sizeof(*mdev), GFP_KERNEL); 205 if (!mdev) 206 return -ENOMEM; 207 208 mdev->mtk_subdev = mtk_subdev; 209 210 rpdev = &mdev->rpdev; 211 rpdev->ops = &mtk_rpmsg_device_ops; 212 rpdev->src = info->src; 213 rpdev->dst = info->dst; 214 strscpy(rpdev->id.name, info->name, RPMSG_NAME_SIZE); 215 216 rpdev->dev.of_node = 217 mtk_rpmsg_match_device_subnode(pdev->dev.of_node, info->name); 218 rpdev->dev.parent = &pdev->dev; 219 rpdev->dev.release = mtk_rpmsg_release_device; 220 221 return rpmsg_register_device(rpdev); 222} 223 224static void mtk_register_device_work_function(struct work_struct *register_work) 225{ 226 struct mtk_rpmsg_rproc_subdev *subdev = container_of( 227 register_work, struct mtk_rpmsg_rproc_subdev, register_work); 228 struct platform_device *pdev = subdev->pdev; 229 struct mtk_rpmsg_channel_info *info; 230 int ret; 231 232 mutex_lock(&subdev->channels_lock); 233 list_for_each_entry(info, &subdev->channels, list) { 234 if (info->registered) 235 continue; 236 237 mutex_unlock(&subdev->channels_lock); 238 ret = mtk_rpmsg_register_device(subdev, &info->info); 239 mutex_lock(&subdev->channels_lock); 240 if (ret) { 241 dev_err(&pdev->dev, "Can't create rpmsg_device\n"); 242 continue; 243 } 244 245 info->registered = true; 246 } 247 mutex_unlock(&subdev->channels_lock); 248} 249 250static int mtk_rpmsg_create_device(struct mtk_rpmsg_rproc_subdev *mtk_subdev, 251 char *name, u32 addr) 252{ 253 struct mtk_rpmsg_channel_info *info; 254 255 info = kzalloc(sizeof(*info), GFP_KERNEL); 256 if (!info) 257 return -ENOMEM; 258 259 strscpy(info->info.name, name, RPMSG_NAME_SIZE); 260 info->info.src = addr; 261 info->info.dst = RPMSG_ADDR_ANY; 262 mutex_lock(&mtk_subdev->channels_lock); 263 list_add(&info->list, &mtk_subdev->channels); 264 mutex_unlock(&mtk_subdev->channels_lock); 265 266 schedule_work(&mtk_subdev->register_work); 267 return 0; 268} 269 270static int mtk_rpmsg_ns_cb(struct rpmsg_device *rpdev, void *data, int len, 271 void *priv, u32 src) 272{ 273 struct rpmsg_ns_msg *msg = data; 274 struct mtk_rpmsg_rproc_subdev *mtk_subdev = priv; 275 struct device *dev = &mtk_subdev->pdev->dev; 276 277 int ret; 278 279 if (len != sizeof(*msg)) { 280 dev_err(dev, "malformed ns msg (%d)\n", len); 281 return -EINVAL; 282 } 283 284 /* 285 * the name service ept does _not_ belong to a real rpmsg channel, 286 * and is handled by the rpmsg bus itself. 287 * for sanity reasons, make sure a valid rpdev has _not_ sneaked 288 * in somehow. 289 */ 290 if (rpdev) { 291 dev_err(dev, "anomaly: ns ept has an rpdev handle\n"); 292 return -EINVAL; 293 } 294 295 /* don't trust the remote processor for null terminating the name */ 296 msg->name[RPMSG_NAME_SIZE - 1] = '\0'; 297 298 dev_info(dev, "creating channel %s addr 0x%x\n", msg->name, msg->addr); 299 300 ret = mtk_rpmsg_create_device(mtk_subdev, msg->name, msg->addr); 301 if (ret) { 302 dev_err(dev, "create rpmsg device failed\n"); 303 return ret; 304 } 305 306 return 0; 307} 308 309static int mtk_rpmsg_prepare(struct rproc_subdev *subdev) 310{ 311 struct mtk_rpmsg_rproc_subdev *mtk_subdev = to_mtk_subdev(subdev); 312 313 /* a dedicated endpoint handles the name service msgs */ 314 if (mtk_subdev->info->ns_ipi_id >= 0) { 315 mtk_subdev->ns_ept = 316 __mtk_create_ept(mtk_subdev, NULL, mtk_rpmsg_ns_cb, 317 mtk_subdev, 318 mtk_subdev->info->ns_ipi_id); 319 if (!mtk_subdev->ns_ept) { 320 dev_err(&mtk_subdev->pdev->dev, 321 "failed to create name service endpoint\n"); 322 return -ENOMEM; 323 } 324 } 325 326 return 0; 327} 328 329static void mtk_rpmsg_unprepare(struct rproc_subdev *subdev) 330{ 331 struct mtk_rpmsg_rproc_subdev *mtk_subdev = to_mtk_subdev(subdev); 332 333 if (mtk_subdev->ns_ept) { 334 mtk_rpmsg_destroy_ept(mtk_subdev->ns_ept); 335 mtk_subdev->ns_ept = NULL; 336 } 337} 338 339static void mtk_rpmsg_stop(struct rproc_subdev *subdev, bool crashed) 340{ 341 struct mtk_rpmsg_channel_info *info, *next; 342 struct mtk_rpmsg_rproc_subdev *mtk_subdev = to_mtk_subdev(subdev); 343 struct device *dev = &mtk_subdev->pdev->dev; 344 345 /* 346 * Destroy the name service endpoint here, to avoid new channel being 347 * created after the rpmsg_unregister_device loop below. 348 */ 349 if (mtk_subdev->ns_ept) { 350 mtk_rpmsg_destroy_ept(mtk_subdev->ns_ept); 351 mtk_subdev->ns_ept = NULL; 352 } 353 354 cancel_work_sync(&mtk_subdev->register_work); 355 356 mutex_lock(&mtk_subdev->channels_lock); 357 list_for_each_entry(info, &mtk_subdev->channels, list) { 358 if (!info->registered) 359 continue; 360 if (rpmsg_unregister_device(dev, &info->info)) { 361 dev_warn( 362 dev, 363 "rpmsg_unregister_device failed for %s.%d.%d\n", 364 info->info.name, info->info.src, 365 info->info.dst); 366 } 367 } 368 369 list_for_each_entry_safe(info, next, 370 &mtk_subdev->channels, list) { 371 list_del(&info->list); 372 kfree(info); 373 } 374 mutex_unlock(&mtk_subdev->channels_lock); 375} 376 377struct rproc_subdev * 378mtk_rpmsg_create_rproc_subdev(struct platform_device *pdev, 379 struct mtk_rpmsg_info *info) 380{ 381 struct mtk_rpmsg_rproc_subdev *mtk_subdev; 382 383 mtk_subdev = kzalloc(sizeof(*mtk_subdev), GFP_KERNEL); 384 if (!mtk_subdev) 385 return NULL; 386 387 mtk_subdev->pdev = pdev; 388 mtk_subdev->subdev.prepare = mtk_rpmsg_prepare; 389 mtk_subdev->subdev.stop = mtk_rpmsg_stop; 390 mtk_subdev->subdev.unprepare = mtk_rpmsg_unprepare; 391 mtk_subdev->info = info; 392 INIT_LIST_HEAD(&mtk_subdev->channels); 393 INIT_WORK(&mtk_subdev->register_work, 394 mtk_register_device_work_function); 395 mutex_init(&mtk_subdev->channels_lock); 396 397 return &mtk_subdev->subdev; 398} 399EXPORT_SYMBOL_GPL(mtk_rpmsg_create_rproc_subdev); 400 401void mtk_rpmsg_destroy_rproc_subdev(struct rproc_subdev *subdev) 402{ 403 struct mtk_rpmsg_rproc_subdev *mtk_subdev = to_mtk_subdev(subdev); 404 405 kfree(mtk_subdev); 406} 407EXPORT_SYMBOL_GPL(mtk_rpmsg_destroy_rproc_subdev); 408 409MODULE_LICENSE("GPL v2"); 410MODULE_DESCRIPTION("MediaTek scp rpmsg driver"); 411