/*
* Copyright (c) 2015, Sony Mobile Communications AB.
* Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* 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.
*/
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/soc/qcom/smem.h>
#include <linux/wait.h>
#include <linux/rpmsg.h>
#include <linux/rpmsg/qcom_smd.h>
#include "rpmsg_internal.h"
/*
* The Qualcomm Shared Memory communication solution provides point-to-point
* channels for clients to send and receive streaming or packet based data.
*
* Each channel consists of a control item (channel info) and a ring buffer
* pair. The channel info carry information related to channel state, flow
* control and the offsets within the ring buffer.
*
* All allocated channels are listed in an allocation table, identifying the
* pair of items by name, type and remote processor.
*
* Upon creating a new channel the remote processor allocates channel info and
* ring buffer items from the smem heap and populate the allocation table. An
* interrupt is sent to the other end of the channel and a scan for new
* channels should be done. A channel never goes away, it will only change
* state.
*
* The remote processor signals it intent for bring up the communication
* channel by setting the state of its end of the channel to "opening" and
* sends out an interrupt. We detect this change and register a smd device to
* consume the channel. Upon finding a consumer we finish the handshake and the
* channel is up.
*
* Upon closing a channel, the remote processor will update the state of its
