| /* |
| * remote processor messaging bus |
| * |
| * Copyright (C) 2011 Texas Instruments, Inc. |
| * Copyright (C) 2011 Google, Inc. |
| * |
| * Ohad Ben-Cohen <ohad@wizery.com> |
| * Brian Swetland <swetland@google.com> |
| * |
| * This software is licensed under the terms of the GNU General Public |
| * License version 2, as published by the Free Software Foundation, and |
| * may be copied, distributed, and modified under those terms. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| */ |
| |
| #define pr_fmt(fmt) "%s: " fmt, __func__ |
| |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/rpmsg.h> |
| #include <linux/of_device.h> |
| #include <linux/slab.h> |
| |
| #include "rpmsg_internal.h" |
| |
| /** |
| * rpmsg_create_ept() - create a new rpmsg_endpoint |
| * @rpdev: rpmsg channel device |
| * @cb: rx callback handler |
| * @priv: private data for the driver's use |
| * @chinfo: channel_info with the local rpmsg address to bind with @cb |
| * |
| * Every rpmsg address in the system is bound to an rx callback (so when |
| * inbound messages arrive, they are dispatched by the rpmsg bus using the |
| * appropriate callback handler) by means of an rpmsg_endpoint struct. |
| * |
| * This function allows drivers to create such an endpoint, and by that, |
| * bind a callback, and possibly some private data too, to an rpmsg address |
| * (either one that is known in advance, or one that will be dynamically |
| * assigned for them). |
| * |
| * Simple rpmsg drivers need not call rpmsg_create_ept, because an endpoint |
| * is already created for them when they are probed by the rpmsg bus |
| * (using the rx callback provided when they registered to the rpmsg bus). |
| * |
| * So things should just work for simple drivers: they already have an |
| * endpoint, their rx callback is bound to their rpmsg address, and when |
| * relevant inbound messages arrive (i.e. messages which their dst address |
| * equals to the src address of their rpmsg channel), the driver's handler |
| * is invoked to process it. |
| * |
| * That said, more complicated drivers might do need to allocate |
| * additional rpmsg addresses, and bind them to different rx callbacks. |
| * To accomplish that, those drivers need to call this function. |
| * |
| * Drivers should provide their @rpdev channel (so the new endpoint would belong |
| * to the same remote processor their channel belongs to), an rx callback |
| * function, an optional private data (which is provided back when the |
| * rx callback is invoked), and an address they want to bind with the |
| * callback. If @addr is RPMSG_ADDR_ANY, then rpmsg_create_ept will |
| * dynamically assign them an available rpmsg address (drivers should have |
| * a very good reason why not to always use RPMSG_ADDR_ANY here). |
| * |
| * Returns a pointer to the endpoint on success, or NULL on error. |
| */ |
| struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *rpdev, |
| rpmsg_rx_cb_t cb, void *priv, |
| struct rpmsg_channel_info chinfo) |
| { |
| return rpdev->ops->create_ept(rpdev, cb, priv, chinfo); |
| } |
| EXPORT_SYMBOL(rpmsg_create_ept); |
| |
| /** |
| * rpmsg_destroy_ept() - destroy an existing rpmsg endpoint |
| * @ept: endpoing to destroy |
| * |
| * Should be used by drivers to destroy an rpmsg endpoint previously |
| * created with rpmsg_create_ept(). |
| */ |
| void rpmsg_destroy_ept(struct rpmsg_endpoint *ept) |
| { |
| ept->ops->destroy_ept(ept); |
| } |
| EXPORT_SYMBOL(rpmsg_destroy_ept); |
| |
| /** |
| * rpmsg_send() - send a message across to the remote processor |
| * @ept: the rpmsg endpoint |
| * @data: payload of message |
| * @len: length of payload |
| * |
| * This function sends @data of length @len on the @ept endpoint. |
| * The message will be sent to the remote processor which the @ept |
| * endpoint belongs to, using @ept's address and its associated rpmsg |
| * device destination addresses. |
| * In case there are no TX buffers available, the function will block until |
| * one becomes available, or a timeout of 15 seconds elapses. When the latter |
| * happens, -ERESTARTSYS is returned. |
| * |
| * Can only be called from process context (for now). |
| * |
| * Returns 0 on success and an appropriate error value on failure. |
| */ |
| int rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len) |
| { |
| return ept->ops->send(ept, data, len); |
| } |
| EXPORT_SYMBOL(rpmsg_send); |
| |
| /** |
| * rpmsg_sendto() - send a message across to the remote processor, specify dst |
| * @ept: the rpmsg endpoint |
| * @data: payload of message |
| * @len: length of payload |
| * @dst: destination address |
| * |
| * This function sends @data of length @len to the remote @dst address. |
| * The message will be sent to the remote processor which the @ept |
| * endpoint belongs to, using @ept's address as source. |
| * In case there are no TX buffers available, the function will block until |
| * one becomes available, or a timeout of 15 seconds elapses. When the latter |
| * happens, -ERESTARTSYS is returned. |
| * |
| * Can only be called from process context (for now). |
| * |
| * Returns 0 on success and an appropriate error value on failure. |
| */ |
| int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst) |
| { |
| return ept->ops->sendto(ept, data, len, dst); |
| } |
| EXPORT_SYMBOL(rpmsg_sendto); |
| |
| /** |
| * rpmsg_send_offchannel() - send a message using explicit src/dst addresses |
| * @ept: the rpmsg endpoint |
| * @src: source address |
| * @dst: destination address |
| * @data: payload of message |
| * @len: length of payload |
| * |
| * This function sends @data of length @len to the remote @dst address, |
| * and uses @src as the source address. |
| * The message will be sent to the remote processor which the @ept |
| * endpoint belongs to. |
| * In case there are no TX buffers available, the function will block until |
| * one becomes available, or a timeout of 15 seconds elapses. When the latter |
| * happens, -ERESTARTSYS is returned. |
| * |
| * Can only be called from process context (for now). |
| * |
| * Returns 0 on success and an appropriate error value on failure. |
| */ |
| int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst, |
| void *data, int len) |
| { |
| return ept->ops->send_offchannel(ept, src, dst, data, len); |
| } |
| EXPORT_SYMBOL(rpmsg_send_offchannel); |
| |
| /** |
| * rpmsg_send() - send a message across to the remote processor |
| * @ept: the rpmsg endpoint |
| * @data: payload of message |
| * @len: length of payload |
| * |
| * This function sends @data of length @len on the @ept endpoint. |
| * The message will be sent to the remote processor which the @ept |
| * endpoint belongs to, using @ept's address as source and its associated |
| * rpdev's address as destination. |
| * In case there are no TX buffers available, the function will immediately |
| * return -ENOMEM without waiting until one becomes available. |
| * |
| * Can only be called from process context (for now). |
| * |
| * Returns 0 on success and an appropriate error value on failure. |
| */ |
| int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len) |
| { |
| return ept->ops->trysend(ept, data, len); |
| } |
| EXPORT_SYMBOL(rpmsg_trysend); |
| |
| /** |
| * rpmsg_sendto() - send a message across to the remote processor, specify dst |
| * @ept: the rpmsg endpoint |
| * @data: payload of message |
| * @len: length of payload |
| * @dst: destination address |
| * |
| * This function sends @data of length @len to the remote @dst address. |
| * The message will be sent to the remote processor which the @ept |
| * endpoint belongs to, using @ept's address as source. |
| * In case there are no TX buffers available, the function will immediately |
| * return -ENOMEM without waiting until one becomes available. |
| * |
| * Can only be called from process context (for now). |
| * |
| * Returns 0 on success and an appropriate error value on failure. |
| */ |
| int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst) |
| { |
| return ept->ops->trysendto(ept, data, len, dst); |
| } |
| EXPORT_SYMBOL(rpmsg_trysendto); |
| |
| /** |
| * rpmsg_send_offchannel() - send a message using explicit src/dst addresses |
| * @ept: the rpmsg endpoint |
| * @src: source address |
| * @dst: destination address |
| * @data: payload of message |
| * @len: length of payload |
| * |
| * This function sends @data of length @len to the remote @dst address, |
| * and uses @src as the source address. |
| * The message will be sent to the remote processor which the @ept |
| * endpoint belongs to. |
| * In case there are no TX buffers available, the function will immediately |
| * return -ENOMEM without waiting until one becomes available. |
| * |
| * Can only be called from process context (for now). |
| * |
| * Returns 0 on success and an appropriate error value on failure. |
| */ |
| int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst, |
| void *data, int len) |
| { |
| return ept->ops->trysend_offchannel(ept, src, dst, data, len); |
| } |
| EXPORT_SYMBOL(rpmsg_trysend_offchannel); |
| |
| /* |
| * match an rpmsg channel with a channel info struct. |
| * this is used to make sure we're not creating rpmsg devices for channels |
| * that already exist. |
| */ |
| static int rpmsg_device_match(struct device *dev, void *data) |
| { |
| struct rpmsg_channel_info *chinfo = data; |
| struct rpmsg_device *rpdev = to_rpmsg_device(dev); |
| |
| if (chinfo->src != RPMSG_ADDR_ANY && chinfo->src != rpdev->src) |
| return 0; |
| |
| if (chinfo->dst != RPMSG_ADDR_ANY && chinfo->dst != rpdev->dst) |
| return 0; |
| |
| if (strncmp(chinfo->name, rpdev->id.name, RPMSG_NAME_SIZE)) |
| return 0; |
| |
| /* found a match ! */ |
| return 1; |
| } |
| |
| struct device *rpmsg_find_device(struct device *parent, |
| struct rpmsg_channel_info *chinfo) |
| { |
| return device_find_child(parent, chinfo, rpmsg_device_match); |
| |
| } |
| EXPORT_SYMBOL(rpmsg_find_device); |
| |
| /* sysfs show configuration fields */ |
| #define rpmsg_show_attr(field, path, format_string) \ |
| static ssize_t \ |
| field##_show(struct device *dev, \ |
| struct device_attribute *attr, char *buf) \ |
| { \ |
| struct rpmsg_device *rpdev = to_rpmsg_device(dev); \ |
| \ |
| return sprintf(buf, format_string, rpdev->path); \ |
| } |
| |
| /* for more info, see Documentation/ABI/testing/sysfs-bus-rpmsg */ |
| rpmsg_show_attr(name, id.name, "%s\n"); |
| rpmsg_show_attr(src, src, "0x%x\n"); |
| rpmsg_show_attr(dst, dst, "0x%x\n"); |
| rpmsg_show_attr(announce, announce ? "true" : "false", "%s\n"); |
| |
| static ssize_t modalias_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct rpmsg_device *rpdev = to_rpmsg_device(dev); |
| |
| return sprintf(buf, RPMSG_DEVICE_MODALIAS_FMT "\n", rpdev->id.name); |
| } |
| |
| static struct device_attribute rpmsg_dev_attrs[] = { |
| __ATTR_RO(name), |
| __ATTR_RO(modalias), |
| __ATTR_RO(dst), |
| __ATTR_RO(src), |
| __ATTR_RO(announce), |
| __ATTR_NULL |
| }; |
| |
| /* rpmsg devices and drivers are matched using the service name */ |
| static inline int rpmsg_id_match(const struct rpmsg_device *rpdev, |
| const struct rpmsg_device_id *id) |
| { |
| return strncmp(id->name, rpdev->id.name, RPMSG_NAME_SIZE) == 0; |
| } |
| |
| /* match rpmsg channel and rpmsg driver */ |
| static int rpmsg_dev_match(struct device *dev, struct device_driver *drv) |
| { |
| struct rpmsg_device *rpdev = to_rpmsg_device(dev); |
| struct rpmsg_driver *rpdrv = to_rpmsg_driver(drv); |
| const struct rpmsg_device_id *ids = rpdrv->id_table; |
| unsigned int i; |
| |
| if (rpdev->driver_override) |
| return !strcmp(rpdev->driver_override, drv->name); |
| |
| if (ids) |
| for (i = 0; ids[i].name[0]; i++) |
| if (rpmsg_id_match(rpdev, &ids[i])) |
| return 1; |
| |
| return of_driver_match_device(dev, drv); |
| } |
| |
| static int rpmsg_uevent(struct device *dev, struct kobj_uevent_env *env) |
| { |
| struct rpmsg_device *rpdev = to_rpmsg_device(dev); |
| |
| return add_uevent_var(env, "MODALIAS=" RPMSG_DEVICE_MODALIAS_FMT, |
| rpdev->id.name); |
| } |
| |
| /* |
| * when an rpmsg driver is probed with a channel, we seamlessly create |
| * it an endpoint, binding its rx callback to a unique local rpmsg |
| * address. |
| * |
| * if we need to, we also announce about this channel to the remote |
| * processor (needed in case the driver is exposing an rpmsg service). |
| */ |
| static int rpmsg_dev_probe(struct device *dev) |
| { |
| struct rpmsg_device *rpdev = to_rpmsg_device(dev); |
| struct rpmsg_driver *rpdrv = to_rpmsg_driver(rpdev->dev.driver); |
| struct rpmsg_channel_info chinfo = {}; |
| struct rpmsg_endpoint *ept; |
| int err; |
| |
| strncpy(chinfo.name, rpdev->id.name, RPMSG_NAME_SIZE); |
| chinfo.src = rpdev->src; |
| chinfo.dst = RPMSG_ADDR_ANY; |
| |
| ept = rpmsg_create_ept(rpdev, rpdrv->callback, NULL, chinfo); |
| if (!ept) { |
| dev_err(dev, "failed to create endpoint\n"); |
| err = -ENOMEM; |
| goto out; |
| } |
| |
| rpdev->ept = ept; |
| rpdev->src = ept->addr; |
| |
| err = rpdrv->probe(rpdev); |
| if (err) { |
| dev_err(dev, "%s: failed: %d\n", __func__, err); |
| rpmsg_destroy_ept(ept); |
| goto out; |
| } |
| |
| if (rpdev->ops->announce_create) |
| err = rpdev->ops->announce_create(rpdev); |
| out: |
| return err; |
| } |
| |
| static int rpmsg_dev_remove(struct device *dev) |
| { |
| struct rpmsg_device *rpdev = to_rpmsg_device(dev); |
| struct rpmsg_driver *rpdrv = to_rpmsg_driver(rpdev->dev.driver); |
| int err = 0; |
| |
| if (rpdev->ops->announce_destroy) |
| err = rpdev->ops->announce_destroy(rpdev); |
| |
| rpdrv->remove(rpdev); |
| |
| rpmsg_destroy_ept(rpdev->ept); |
| |
| return err; |
| } |
| |
| static struct bus_type rpmsg_bus = { |
| .name = "rpmsg", |
| .match = rpmsg_dev_match, |
| .dev_attrs = rpmsg_dev_attrs, |
| .uevent = rpmsg_uevent, |
| .probe = rpmsg_dev_probe, |
| .remove = rpmsg_dev_remove, |
| }; |
| |
| static void rpmsg_release_device(struct device *dev) |
| { |
| struct rpmsg_device *rpdev = to_rpmsg_device(dev); |
| |
| kfree(rpdev); |
| } |
| |
| int rpmsg_register_device(struct rpmsg_device *rpdev) |
| { |
| struct device *dev = &rpdev->dev; |
| int ret; |
| |
| dev_set_name(&rpdev->dev, "%s.%s.%d.%d", dev_name(dev->parent), |
| rpdev->id.name, rpdev->src, rpdev->dst); |
| |
| rpdev->dev.bus = &rpmsg_bus; |
| rpdev->dev.release = rpmsg_release_device; |
| |
| ret = device_register(&rpdev->dev); |
| if (ret) { |
| dev_err(dev, "device_register failed: %d\n", ret); |
| put_device(&rpdev->dev); |
| } |
| |
| return ret; |
| } |
| EXPORT_SYMBOL(rpmsg_register_device); |
| |
| /* |
| * find an existing channel using its name + address properties, |
| * and destroy it |
| */ |
| int rpmsg_unregister_device(struct device *parent, |
| struct rpmsg_channel_info *chinfo) |
| { |
| struct device *dev; |
| |
| dev = rpmsg_find_device(parent, chinfo); |
| if (!dev) |
| return -EINVAL; |
| |
| device_unregister(dev); |
| |
| put_device(dev); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(rpmsg_unregister_device); |
| |
| /** |
| * __register_rpmsg_driver() - register an rpmsg driver with the rpmsg bus |
| * @rpdrv: pointer to a struct rpmsg_driver |
| * @owner: owning module/driver |
| * |
| * Returns 0 on success, and an appropriate error value on failure. |
| */ |
| int __register_rpmsg_driver(struct rpmsg_driver *rpdrv, struct module *owner) |
| { |
| rpdrv->drv.bus = &rpmsg_bus; |
| rpdrv->drv.owner = owner; |
| return driver_register(&rpdrv->drv); |
| } |
| EXPORT_SYMBOL(__register_rpmsg_driver); |
| |
| /** |
| * unregister_rpmsg_driver() - unregister an rpmsg driver from the rpmsg bus |
| * @rpdrv: pointer to a struct rpmsg_driver |
| * |
| * Returns 0 on success, and an appropriate error value on failure. |
| */ |
| void unregister_rpmsg_driver(struct rpmsg_driver *rpdrv) |
| { |
| driver_unregister(&rpdrv->drv); |
| } |
| EXPORT_SYMBOL(unregister_rpmsg_driver); |
| |
| |
| static int __init rpmsg_init(void) |
| { |
| int ret; |
| |
| ret = bus_register(&rpmsg_bus); |
| if (ret) |
| pr_err("failed to register rpmsg bus: %d\n", ret); |
| |
| return ret; |
| } |
| postcore_initcall(rpmsg_init); |
| |
| static void __exit rpmsg_fini(void) |
| { |
| bus_unregister(&rpmsg_bus); |
| } |
| module_exit(rpmsg_fini); |
| |
| MODULE_DESCRIPTION("remote processor messaging bus"); |
| MODULE_LICENSE("GPL v2"); |