|  | /* | 
|  | * Remote processor messaging | 
|  | * | 
|  | * Copyright (C) 2011 Texas Instruments, Inc. | 
|  | * Copyright (C) 2011 Google, Inc. | 
|  | * All rights reserved. | 
|  | * | 
|  | * Redistribution and use in source and binary forms, with or without | 
|  | * modification, are permitted provided that the following conditions | 
|  | * are met: | 
|  | * | 
|  | * * Redistributions of source code must retain the above copyright | 
|  | *   notice, this list of conditions and the following disclaimer. | 
|  | * * Redistributions in binary form must reproduce the above copyright | 
|  | *   notice, this list of conditions and the following disclaimer in | 
|  | *   the documentation and/or other materials provided with the | 
|  | *   distribution. | 
|  | * * Neither the name Texas Instruments nor the names of its | 
|  | *   contributors may be used to endorse or promote products derived | 
|  | *   from this software without specific prior written permission. | 
|  | * | 
|  | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | 
|  | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | 
|  | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | 
|  | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | 
|  | * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | 
|  | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | 
|  | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | 
|  | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | 
|  | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | 
|  | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | 
|  | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | 
|  | */ | 
|  |  | 
|  | #ifndef _LINUX_RPMSG_H | 
|  | #define _LINUX_RPMSG_H | 
|  |  | 
|  | #include <linux/types.h> | 
|  | #include <linux/device.h> | 
|  | #include <linux/mod_devicetable.h> | 
|  | #include <linux/kref.h> | 
|  | #include <linux/mutex.h> | 
|  |  | 
|  | /* The feature bitmap for virtio rpmsg */ | 
|  | #define VIRTIO_RPMSG_F_NS	0 /* RP supports name service notifications */ | 
|  |  | 
|  | /** | 
|  | * struct rpmsg_hdr - common header for all rpmsg messages | 
|  | * @src: source address | 
|  | * @dst: destination address | 
|  | * @reserved: reserved for future use | 
|  | * @len: length of payload (in bytes) | 
|  | * @flags: message flags | 
|  | * @data: @len bytes of message payload data | 
|  | * | 
|  | * Every message sent(/received) on the rpmsg bus begins with this header. | 
|  | */ | 
|  | struct rpmsg_hdr { | 
|  | u32 src; | 
|  | u32 dst; | 
|  | u32 reserved; | 
|  | u16 len; | 
|  | u16 flags; | 
|  | u8 data[0]; | 
|  | } __packed; | 
|  |  | 
|  | /** | 
|  | * struct rpmsg_ns_msg - dynamic name service announcement message | 
|  | * @name: name of remote service that is published | 
|  | * @addr: address of remote service that is published | 
|  | * @flags: indicates whether service is created or destroyed | 
|  | * | 
|  | * This message is sent across to publish a new service, or announce | 
|  | * about its removal. When we receive these messages, an appropriate | 
|  | * rpmsg channel (i.e device) is created/destroyed. In turn, the ->probe() | 
|  | * or ->remove() handler of the appropriate rpmsg driver will be invoked | 
|  | * (if/as-soon-as one is registered). | 
|  | */ | 
|  | struct rpmsg_ns_msg { | 
|  | char name[RPMSG_NAME_SIZE]; | 
|  | u32 addr; | 
|  | u32 flags; | 
|  | } __packed; | 
|  |  | 
|  | /** | 
|  | * enum rpmsg_ns_flags - dynamic name service announcement flags | 
|  | * | 
|  | * @RPMSG_NS_CREATE: a new remote service was just created | 
|  | * @RPMSG_NS_DESTROY: a known remote service was just destroyed | 
|  | */ | 
|  | enum rpmsg_ns_flags { | 
|  | RPMSG_NS_CREATE		= 0, | 
|  | RPMSG_NS_DESTROY	= 1, | 
|  | }; | 
|  |  | 
|  | #define RPMSG_ADDR_ANY		0xFFFFFFFF | 
|  |  | 
|  | struct virtproc_info; | 
|  |  | 
|  | /** | 
|  | * rpmsg_channel - devices that belong to the rpmsg bus are called channels | 
|  | * @vrp: the remote processor this channel belongs to | 
|  | * @dev: the device struct | 
|  | * @id: device id (used to match between rpmsg drivers and devices) | 
|  | * @src: local address | 
|  | * @dst: destination address | 
|  | * @ept: the rpmsg endpoint of this channel | 
|  | * @announce: if set, rpmsg will announce the creation/removal of this channel | 
|  | */ | 
|  | struct rpmsg_channel { | 
|  | struct virtproc_info *vrp; | 
|  | struct device dev; | 
|  | struct rpmsg_device_id id; | 
|  | u32 src; | 
|  | u32 dst; | 
|  | struct rpmsg_endpoint *ept; | 
|  | bool announce; | 
|  | }; | 
|  |  | 
|  | typedef void (*rpmsg_rx_cb_t)(struct rpmsg_channel *, void *, int, void *, u32); | 
|  |  | 
|  | /** | 
|  | * struct rpmsg_endpoint - binds a local rpmsg address to its user | 
|  | * @rpdev: rpmsg channel device | 
|  | * @refcount: when this drops to zero, the ept is deallocated | 
|  | * @cb: rx callback handler | 
|  | * @cb_lock: must be taken before accessing/changing @cb | 
|  | * @addr: local rpmsg address | 
|  | * @priv: private data for the driver's use | 
|  | * | 
|  | * In essence, an rpmsg endpoint represents a listener on the rpmsg bus, as | 
|  | * it binds an rpmsg address with an rx callback handler. | 
|  | * | 
|  | * Simple rpmsg drivers shouldn't use this struct directly, because | 
|  | * things just work: every rpmsg driver provides an rx callback upon | 
|  | * registering to the bus, and that callback is then bound to its rpmsg | 
|  | * address when the driver is probed. When relevant inbound messages arrive | 
|  | * (i.e. messages which their dst address equals to the src address of | 
|  | * the rpmsg channel), the driver's handler is invoked to process it. | 
|  | * | 
|  | * More complicated drivers though, that do need to allocate additional rpmsg | 
|  | * addresses, and bind them to different rx callbacks, must explicitly | 
|  | * create additional endpoints by themselves (see rpmsg_create_ept()). | 
|  | */ | 
|  | struct rpmsg_endpoint { | 
|  | struct rpmsg_channel *rpdev; | 
|  | struct kref refcount; | 
|  | rpmsg_rx_cb_t cb; | 
|  | struct mutex cb_lock; | 
|  | u32 addr; | 
|  | void *priv; | 
|  | }; | 
|  |  | 
|  | /** | 
|  | * struct rpmsg_driver - rpmsg driver struct | 
|  | * @drv: underlying device driver | 
|  | * @id_table: rpmsg ids serviced by this driver | 
|  | * @probe: invoked when a matching rpmsg channel (i.e. device) is found | 
|  | * @remove: invoked when the rpmsg channel is removed | 
|  | * @callback: invoked when an inbound message is received on the channel | 
|  | */ | 
|  | struct rpmsg_driver { | 
|  | struct device_driver drv; | 
|  | const struct rpmsg_device_id *id_table; | 
|  | int (*probe)(struct rpmsg_channel *dev); | 
|  | void (*remove)(struct rpmsg_channel *dev); | 
|  | void (*callback)(struct rpmsg_channel *, void *, int, void *, u32); | 
|  | }; | 
|  |  | 
|  | int register_rpmsg_device(struct rpmsg_channel *dev); | 
|  | void unregister_rpmsg_device(struct rpmsg_channel *dev); | 
|  | int register_rpmsg_driver(struct rpmsg_driver *drv); | 
|  | void unregister_rpmsg_driver(struct rpmsg_driver *drv); | 
|  | void rpmsg_destroy_ept(struct rpmsg_endpoint *); | 
|  | struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_channel *, | 
|  | rpmsg_rx_cb_t cb, void *priv, u32 addr); | 
|  | int | 
|  | rpmsg_send_offchannel_raw(struct rpmsg_channel *, u32, u32, void *, int, bool); | 
|  |  | 
|  | /** | 
|  | * rpmsg_send() - send a message across to the remote processor | 
|  | * @rpdev: the rpmsg channel | 
|  | * @data: payload of message | 
|  | * @len: length of payload | 
|  | * | 
|  | * This function sends @data of length @len on the @rpdev channel. | 
|  | * The message will be sent to the remote processor which the @rpdev | 
|  | * channel belongs to, using @rpdev's source and 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. | 
|  | */ | 
|  | static inline int rpmsg_send(struct rpmsg_channel *rpdev, void *data, int len) | 
|  | { | 
|  | u32 src = rpdev->src, dst = rpdev->dst; | 
|  |  | 
|  | return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * rpmsg_sendto() - send a message across to the remote processor, specify dst | 
|  | * @rpdev: the rpmsg channel | 
|  | * @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 @rpdev | 
|  | * channel belongs to, using @rpdev's source address. | 
|  | * 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. | 
|  | */ | 
|  | static inline | 
|  | int rpmsg_sendto(struct rpmsg_channel *rpdev, void *data, int len, u32 dst) | 
|  | { | 
|  | u32 src = rpdev->src; | 
|  |  | 
|  | return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * rpmsg_send_offchannel() - send a message using explicit src/dst addresses | 
|  | * @rpdev: the rpmsg channel | 
|  | * @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 @rpdev | 
|  | * channel 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. | 
|  | */ | 
|  | static inline | 
|  | int rpmsg_send_offchannel(struct rpmsg_channel *rpdev, u32 src, u32 dst, | 
|  | void *data, int len) | 
|  | { | 
|  | return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * rpmsg_send() - send a message across to the remote processor | 
|  | * @rpdev: the rpmsg channel | 
|  | * @data: payload of message | 
|  | * @len: length of payload | 
|  | * | 
|  | * This function sends @data of length @len on the @rpdev channel. | 
|  | * The message will be sent to the remote processor which the @rpdev | 
|  | * channel belongs to, using @rpdev's source and destination addresses. | 
|  | * 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. | 
|  | */ | 
|  | static inline | 
|  | int rpmsg_trysend(struct rpmsg_channel *rpdev, void *data, int len) | 
|  | { | 
|  | u32 src = rpdev->src, dst = rpdev->dst; | 
|  |  | 
|  | return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * rpmsg_sendto() - send a message across to the remote processor, specify dst | 
|  | * @rpdev: the rpmsg channel | 
|  | * @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 @rpdev | 
|  | * channel belongs to, using @rpdev's source address. | 
|  | * 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. | 
|  | */ | 
|  | static inline | 
|  | int rpmsg_trysendto(struct rpmsg_channel *rpdev, void *data, int len, u32 dst) | 
|  | { | 
|  | u32 src = rpdev->src; | 
|  |  | 
|  | return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * rpmsg_send_offchannel() - send a message using explicit src/dst addresses | 
|  | * @rpdev: the rpmsg channel | 
|  | * @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 @rpdev | 
|  | * channel 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. | 
|  | */ | 
|  | static inline | 
|  | int rpmsg_trysend_offchannel(struct rpmsg_channel *rpdev, u32 src, u32 dst, | 
|  | void *data, int len) | 
|  | { | 
|  | return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false); | 
|  | } | 
|  |  | 
|  | #endif /* _LINUX_RPMSG_H */ |