Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0
//
// Copyright 2018 Google LLC.
 
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_data/cros_ec_commands.h>
#include <linux/platform_data/cros_ec_proto.h>
#include <linux/platform_device.h>
#include <linux/rpmsg.h>
#include <linux/slab.h>
 
#include "cros_ec.h"
 
#define EC_MSG_TIMEOUT_MS	200
#define HOST_COMMAND_MARK	1
#define HOST_EVENT_MARK		2
 
/**
 * struct cros_ec_rpmsg_response - rpmsg message format from from EC.
 *
 * @type:	The type of message, should be either HOST_COMMAND_MARK or
 *		HOST_EVENT_MARK, representing that the message is a response to
 *		host command, or a host event.
 * @data:	ec_host_response for host command.
 */
struct cros_ec_rpmsg_response {
<------>u8 type;
<------>u8 data[] __aligned(4);
};
 
/**
 * struct cros_ec_rpmsg - information about a EC over rpmsg.
 *
 * @rpdev:	rpmsg device we are connected to
 * @xfer_ack:	completion for host command transfer.
 * @host_event_work:	Work struct for pending host event.
 * @ept: The rpmsg endpoint of this channel.
 * @has_pending_host_event: Boolean used to check if there is a pending event.
 * @probe_done: Flag to indicate that probe is done.
 */
struct cros_ec_rpmsg {
<------>struct rpmsg_device *rpdev;
<------>struct completion xfer_ack;
<------>struct work_struct host_event_work;
<------>struct rpmsg_endpoint *ept;
<------>bool has_pending_host_event;
<------>bool probe_done;
};
 
/**
 * cros_ec_cmd_xfer_rpmsg - Transfer a message over rpmsg and receive the reply
 *
 * @ec_dev: ChromeOS EC device
 * @ec_msg: Message to transfer
 *
 * This is only used for old EC proto version, and is not supported for this
 * driver.
 *
 * Return: -EINVAL
 */
static int cros_ec_cmd_xfer_rpmsg(struct cros_ec_device *ec_dev,
<------><------><------><------>  struct cros_ec_command *ec_msg)
{
<------>return -EINVAL;
}
 
/**
 * cros_ec_pkt_xfer_rpmsg - Transfer a packet over rpmsg and receive the reply
 *
 * @ec_dev: ChromeOS EC device
 * @ec_msg: Message to transfer
 *
 * Return: number of bytes of the reply on success or negative error code.
 */
static int cros_ec_pkt_xfer_rpmsg(struct cros_ec_device *ec_dev,
<------><------><------><------>  struct cros_ec_command *ec_msg)
{
<------>struct cros_ec_rpmsg *ec_rpmsg = ec_dev->priv;
<------>struct ec_host_response *response;
<------>unsigned long timeout;
<------>int len;
<------>int ret;
<------>u8 sum;
<------>int i;
 
<------>ec_msg->result = 0;
<------>len = cros_ec_prepare_tx(ec_dev, ec_msg);
<------>dev_dbg(ec_dev->dev, "prepared, len=%d\n", len);
 
<------>reinit_completion(&ec_rpmsg->xfer_ack);
<------>ret = rpmsg_send(ec_rpmsg->ept, ec_dev->dout, len);
<------>if (ret) {
<------><------>dev_err(ec_dev->dev, "rpmsg send failed\n");
<------><------>return ret;
<------>}
 
<------>timeout = msecs_to_jiffies(EC_MSG_TIMEOUT_MS);
<------>ret = wait_for_completion_timeout(&ec_rpmsg->xfer_ack, timeout);
<------>if (!ret) {
<------><------>dev_err(ec_dev->dev, "rpmsg send timeout\n");
<------><------>return -EIO;
<------>}
 
<------>/* check response error code */
<------>response = (struct ec_host_response *)ec_dev->din;
<------>ec_msg->result = response->result;
 
<------>ret = cros_ec_check_result(ec_dev, ec_msg);
<------>if (ret)
<------><------>goto exit;
 
<------>if (response->data_len > ec_msg->insize) {
<------><------>dev_err(ec_dev->dev, "packet too long (%d bytes, expected %d)",
<------><------><------>response->data_len, ec_msg->insize);
<------><------>ret = -EMSGSIZE;
<------><------>goto exit;
<------>}
 
<------>/* copy response packet payload and compute checksum */
<------>memcpy(ec_msg->data, ec_dev->din + sizeof(*response),
<------>       response->data_len);
 
<------>sum = 0;
<------>for (i = 0; i < sizeof(*response) + response->data_len; i++)
<------><------>sum += ec_dev->din[i];
 
<------>if (sum) {
<------><------>dev_err(ec_dev->dev, "bad packet checksum, calculated %x\n",
<------><------><------>sum);
<------><------>ret = -EBADMSG;
<------><------>goto exit;
<------>}
 
<------>ret = response->data_len;
exit:
<------>if (ec_msg->command == EC_CMD_REBOOT_EC)
<------><------>msleep(EC_REBOOT_DELAY_MS);
 
<------>return ret;
}
 
static void
cros_ec_rpmsg_host_event_function(struct work_struct *host_event_work)
{
<------>struct cros_ec_rpmsg *ec_rpmsg = container_of(host_event_work,
<------><------><------><------><------><------>      struct cros_ec_rpmsg,
<------><------><------><------><------><------>      host_event_work);
<------>struct cros_ec_device *ec_dev = dev_get_drvdata(&ec_rpmsg->rpdev->dev);
<------>bool ec_has_more_events;
 
<------>do {
<------><------>ec_has_more_events = cros_ec_handle_event(ec_dev);
<------>} while (ec_has_more_events);
}
 
static int cros_ec_rpmsg_callback(struct rpmsg_device *rpdev, void *data,
<------><------><------><------>  int len, void *priv, u32 src)
{
<------>struct cros_ec_device *ec_dev = dev_get_drvdata(&rpdev->dev);
<------>struct cros_ec_rpmsg *ec_rpmsg = ec_dev->priv;
<------>struct cros_ec_rpmsg_response *resp;
 
<------>if (!len) {
<------><------>dev_warn(ec_dev->dev, "rpmsg received empty response");
<------><------>return -EINVAL;
<------>}
 
<------>resp = data;
<------>len -= offsetof(struct cros_ec_rpmsg_response, data);
<------>if (resp->type == HOST_COMMAND_MARK) {
<------><------>if (len > ec_dev->din_size) {
<------><------><------>dev_warn(ec_dev->dev,
<------><------><------><------> "received length %d > din_size %d, truncating",
<------><------><------><------> len, ec_dev->din_size);
<------><------><------>len = ec_dev->din_size;
<------><------>}
 
<------><------>memcpy(ec_dev->din, resp->data, len);
<------><------>complete(&ec_rpmsg->xfer_ack);
<------>} else if (resp->type == HOST_EVENT_MARK) {
<------><------>/*
<------><------> * If the host event is sent before cros_ec_register is
<------><------> * finished, queue the host event.
<------><------> */
<------><------>if (ec_rpmsg->probe_done)
<------><------><------>schedule_work(&ec_rpmsg->host_event_work);
<------><------>else
<------><------><------>ec_rpmsg->has_pending_host_event = true;
<------>} else {
<------><------>dev_warn(ec_dev->dev, "rpmsg received invalid type = %d",
<------><------><------> resp->type);
<------><------>return -EINVAL;
<------>}
 
<------>return 0;
}
 
static struct rpmsg_endpoint *
cros_ec_rpmsg_create_ept(struct rpmsg_device *rpdev)
{
<------>struct rpmsg_channel_info chinfo = {};
 
<------>strscpy(chinfo.name, rpdev->id.name, RPMSG_NAME_SIZE);
<------>chinfo.src = rpdev->src;
<------>chinfo.dst = RPMSG_ADDR_ANY;
 
<------>return rpmsg_create_ept(rpdev, cros_ec_rpmsg_callback, NULL, chinfo);
}
 
static int cros_ec_rpmsg_probe(struct rpmsg_device *rpdev)
{
<------>struct device *dev = &rpdev->dev;
<------>struct cros_ec_rpmsg *ec_rpmsg;
<------>struct cros_ec_device *ec_dev;
<------>int ret;
 
<------>ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL);
<------>if (!ec_dev)
<------><------>return -ENOMEM;
 
<------>ec_rpmsg = devm_kzalloc(dev, sizeof(*ec_rpmsg), GFP_KERNEL);
<------>if (!ec_rpmsg)
<------><------>return -ENOMEM;
 
<------>ec_dev->dev = dev;
<------>ec_dev->priv = ec_rpmsg;
<------>ec_dev->cmd_xfer = cros_ec_cmd_xfer_rpmsg;
<------>ec_dev->pkt_xfer = cros_ec_pkt_xfer_rpmsg;
<------>ec_dev->phys_name = dev_name(&rpdev->dev);
<------>ec_dev->din_size = sizeof(struct ec_host_response) +
<------><------><------>   sizeof(struct ec_response_get_protocol_info);
<------>ec_dev->dout_size = sizeof(struct ec_host_request);
<------>dev_set_drvdata(dev, ec_dev);
 
<------>ec_rpmsg->rpdev = rpdev;
<------>init_completion(&ec_rpmsg->xfer_ack);
<------>INIT_WORK(&ec_rpmsg->host_event_work,
<------><------>  cros_ec_rpmsg_host_event_function);
 
<------>ec_rpmsg->ept = cros_ec_rpmsg_create_ept(rpdev);
<------>if (!ec_rpmsg->ept)
<------><------>return -ENOMEM;
 
<------>ret = cros_ec_register(ec_dev);
<------>if (ret < 0) {
<------><------>rpmsg_destroy_ept(ec_rpmsg->ept);
<------><------>cancel_work_sync(&ec_rpmsg->host_event_work);
<------><------>return ret;
<------>}
 
<------>ec_rpmsg->probe_done = true;
 
<------>if (ec_rpmsg->has_pending_host_event)
<------><------>schedule_work(&ec_rpmsg->host_event_work);
 
<------>return 0;
}
 
static void cros_ec_rpmsg_remove(struct rpmsg_device *rpdev)
{
<------>struct cros_ec_device *ec_dev = dev_get_drvdata(&rpdev->dev);
<------>struct cros_ec_rpmsg *ec_rpmsg = ec_dev->priv;
 
<------>cros_ec_unregister(ec_dev);
<------>rpmsg_destroy_ept(ec_rpmsg->ept);
<------>cancel_work_sync(&ec_rpmsg->host_event_work);
}
 
#ifdef CONFIG_PM_SLEEP
static int cros_ec_rpmsg_suspend(struct device *dev)
{
<------>struct cros_ec_device *ec_dev = dev_get_drvdata(dev);
 
<------>return cros_ec_suspend(ec_dev);
}
 
static int cros_ec_rpmsg_resume(struct device *dev)
{
<------>struct cros_ec_device *ec_dev = dev_get_drvdata(dev);
 
<------>return cros_ec_resume(ec_dev);
}
#endif
 
static SIMPLE_DEV_PM_OPS(cros_ec_rpmsg_pm_ops, cros_ec_rpmsg_suspend,
<------><------><------> cros_ec_rpmsg_resume);
 
static const struct of_device_id cros_ec_rpmsg_of_match[] = {
<------>{ .compatible = "google,cros-ec-rpmsg", },
<------>{ }
};
MODULE_DEVICE_TABLE(of, cros_ec_rpmsg_of_match);
 
static struct rpmsg_driver cros_ec_driver_rpmsg = {
<------>.drv = {
<------><------>.name   = "cros-ec-rpmsg",
<------><------>.of_match_table = cros_ec_rpmsg_of_match,
<------><------>.pm	= &cros_ec_rpmsg_pm_ops,
<------>},
<------>.probe		= cros_ec_rpmsg_probe,
<------>.remove		= cros_ec_rpmsg_remove,
};
 
module_rpmsg_driver(cros_ec_driver_rpmsg);
 
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("ChromeOS EC multi function device (rpmsg)");