path: root/drivers/misc/mei/bus.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2012-2019, Intel Corporation. All rights reserved.
 * Intel Management Engine Interface (Intel MEI) Linux driver
 */

#include <linux/module.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/sched/signal.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/interrupt.h>
#include <linux/mei_cl_bus.h>

#include "mei_dev.h"
#include "client.h"

#define to_mei_cl_driver(d) container_of(d, struct mei_cl_driver, driver)

/**
 * __mei_cl_send - internal client send (write)
 *
 * @cl: host client
 * @buf: buffer to send
 * @length: buffer length
 * @vtag: virtual tag
 * @mode: sending mode
 *
 * Return: written size bytes or < 0 on error
 */
ssize_t __mei_cl_send(struct mei_cl *cl, const u8 *buf, size_t length, u8 vtag,
		      unsigned int mode)
{
	return __mei_cl_send_timeout(cl, buf, length, vtag, mode, MAX_SCHEDULE_TIMEOUT);
}

/**
 * __mei_cl_send_timeout - internal client send (write)
 *
 * @cl: host client
 * @buf: buffer to send
 * @length: buffer length
 * @vtag: virtual tag
 * @mode: sending mode
 * @timeout: send timeout in milliseconds.
 *           effective only for blocking writes: the MEI_CL_IO_TX_BLOCKING mode bit is set.
 *           set timeout to the MAX_SCHEDULE_TIMEOUT to maixum allowed wait.
 *
 * Return: written size bytes or < 0 on error
 */
ssize_t __mei_cl_send_timeout(struct mei_cl *cl, const u8 *buf, size_t length, u8 vtag,
			      unsigned int mode, unsigned long timeout)
{
	struct mei_device *bus;
	struct mei_cl_cb *cb;
	ssize_t rets;

	if (WARN_ON(!cl || !cl->dev))
		return -ENODEV;

	bus = cl->dev;

	mutex_lock(&bus->device_lock);
	if (bus->dev_state != MEI_DEV_ENABLED &&
	    bus->dev_state != MEI_DEV_POWERING_DOWN) {
		rets = -ENODEV;
		goto out;