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// SPDX-License-Identifier: GPL-2.0
/*
* rpmsg client driver using mailbox client interface
*
* Copyright (C) 2019 ARM Ltd.
*
*/
#include <linux/bitmap.h>
#include <linux/export.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/ktime.h>
#include <linux/mailbox_client.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/processor.h>
#include <linux/semaphore.h>
#include <linux/slab.h>
#include <linux/rpmsg.h>
#include "rpmsg_internal.h"
#define RPMSG_NAME "arm_rpmsg"
#define RPMSG_ADDR_ANY 0xFFFFFFFF
#define TX_TIMEOUT 500 /*by half second*/
struct arm_ept_info {
struct rpmsg_channel_info info;
struct rpmsg_endpoint *ept;
struct mbox_client *cl;
struct list_head node;
};
static LIST_HEAD(arm_ept_infos);
static void arm_msg_rx_handler(struct mbox_client *cl, void *mssg)
{
struct arm_ept_info *it = NULL;
list_for_each_entry(it, &arm_ept_infos, node) {
if (it->cl == cl) {
struct rpmsg_endpoint *ept = it->ept;
ept->cb(ept->rpdev, mssg, 4, ept->priv, RPMSG_ADDR_ANY);
return;
}
}
}
static void arm_destroy_ept(struct rpmsg_endpoint *ept)
{
struct arm_ept_info *it = NULL;
list_for_each_entry(it, &arm_ept_infos, node) {
if (it->ept == ept) {
list_del(&it->node);
kfree(it);
break;
}
}
kfree(ept);
}
static int arm_send(struct rpmsg_endpoint *ept, void *data, int len)
{
struct arm_ept_info *it = NULL;
struct arm_ept_info *arm_ept = NULL;
struct mbox_client *cl;
struct mbox_chan *mbox;
// Locate registered endpoint
list_for_each_entry(it, &arm_ept_infos, node) {
if (it->ept == ept) {
arm_ept = it;
break;
}
}
if (arm_ept == NULL) {
dev_printk(KERN_ERR, cl->dev,
"RPMsg ARM: Invalid endpoint\n");
return -1;
}
cl = kzalloc(sizeof(struct mbox_client), GFP_KERNEL);
cl->dev = ept->rpdev->dev.parent;
cl->rx_callback = arm_msg_rx_handler;
cl->tx_done = NULL; /* operate in blocking mode */
cl->tx_block = true;
cl->tx_tout = TX_TIMEOUT; /* by half a second */
cl->knows_txdone = false; /* depending upon protocol */
arm_ept->cl = cl;
mbox = mbox_request_channel_byname(cl, arm_ept->info.name);
if (IS_ERR_OR_NULL(mbox)) {
dev_printk(KERN_ERR, cl->dev,
"RPMsg ARM: Cannot get channel by name: '%s'\n",
arm_ept->info.name);
return -1;
}
mbox_send_message(mbox, data);
mbox_free_channel(mbox);
return 0;
}
static const struct rpmsg_endpoint_ops arm_endpoint_ops = {
.destroy_ept = arm_destroy_ept,
.send = arm_send,
};
static struct rpmsg_endpoint *arm_create_ept(struct rpmsg_device *rpdev,
rpmsg_rx_cb_t cb, void *priv, struct rpmsg_channel_info chinfo)
{
struct rpmsg_endpoint *ept;
struct arm_ept_info *ept_mbox;
ept = kzalloc(sizeof(*ept), GFP_KERNEL);
if (!ept)
return NULL;
kref_init(&ept->refcount);
ept->rpdev = rpdev;
ept->cb = cb;
ept->priv = priv;
ept->ops = &arm_endpoint_ops;
// store chinfo for determining destination mailbox when sending
ept_mbox = kzalloc(sizeof(*ept_mbox), GFP_KERNEL);
ept_mbox->info = chinfo;
strncpy(ept_mbox->info.name, chinfo.name, RPMSG_NAME_SIZE);
ept_mbox->ept = ept;
list_add(&ept_mbox->node, &arm_ept_infos);
return ept;
}
static const struct rpmsg_device_ops arm_device_ops = {
.create_ept = arm_create_ept,
};
static void arm_release_device(struct device *dev)
{
struct rpmsg_device *rpdev = to_rpmsg_device(dev);
kfree(rpdev);
}
static int client_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct rpmsg_device *rpdev;
rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
if (!rpdev)
return -ENOMEM;
/* Assign callbacks for rpmsg_device */
rpdev->ops = &arm_device_ops;
/* Assign public information to the rpmsg_device */
memcpy(rpdev->id.name, RPMSG_NAME, strlen(RPMSG_NAME));
rpdev->dev.parent = dev;
rpdev->dev.release = arm_release_device;
return rpmsg_chrdev_register_device(rpdev);
}
static const struct of_device_id client_of_match[] = {
{ .compatible = "arm,client", .data = NULL },
{ /* Sentinel */ },
};
static struct platform_driver client_driver = {
.driver = {
.name = "arm-mhu-client",
.of_match_table = client_of_match,
},
.probe = client_probe,
};
module_platform_driver(client_driver);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("ARM RPMSG Driver");
MODULE_AUTHOR("Tushar Khandelwal <tushar.khandelwal@arm.com>");
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