// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2020-2023, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 */

#include <linux/version.h>

#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/completion.h>
#include <linux/mailbox_client.h>
#include <linux/sched.h>
#include <linux/sched/clock.h>
#include <linux/err.h>

#include <aon.h>
#include <aon-hsp-combo.h>

#define TX_BLOCK_PERIOD 20

struct aon_hsp_sm {
	struct mbox_client client;
	struct mbox_chan *chan;
};

struct aon_hsp {
	struct aon_hsp_sm rx;
	struct aon_hsp_sm tx;
	struct device dev;
	struct completion emptied;
	void (*full_notify)(void *data, u32 value);
	void *pdata;
};

static void aon_hsp_rx_full_notify(struct mbox_client *cl, void *data)
{
	struct aon_hsp *aonhsp = dev_get_drvdata(cl->dev);
	u32 msg = (u32) (unsigned long) data;

	aonhsp->full_notify(aonhsp->pdata, msg);
}

static void aon_hsp_tx_empty_notify(struct mbox_client *cl, void *data,
				    int empty_value)
{
	struct aon_hsp *aonhsp = dev_get_drvdata(cl->dev);

	(void)empty_value;	/* ignored */

	complete(&aonhsp->emptied);
}

static int aon_hsp_probe(struct aon_hsp *aonhsp)
{
	struct device_node *np = aonhsp->dev.parent->of_node;
	int err = -ENODEV;

	np = of_get_compatible_child(np, "nvidia,tegra-aon-hsp");
	if (np == NULL || !of_device_is_available(np)) {
		of_node_put(np);
		dev_err(&aonhsp->dev, "no hsp protocol \"%s\"\n",
				"nvidia,tegra-aon-hsp");
		return -ENODEV;
	}

	aonhsp->dev.of_node = np;

	aonhsp->rx.chan = mbox_request_channel_byname(&aonhsp->rx.client,
						      "ivc-rx");
	if (IS_ERR(aonhsp->rx.chan)) {
		err = PTR_ERR(aonhsp->rx.chan);
		goto fail;
	}

	aonhsp->tx.chan = mbox_request_channel_byname(&aonhsp->tx.client,
						      "ivc-tx");
	if (IS_ERR(aonhsp->tx.chan)) {
		err = PTR_ERR(aonhsp->tx.chan);
		goto fail;
	}

	dev_set_name(&aonhsp->dev, "%s:%s", dev_name(aonhsp->dev.parent),
		     aonhsp->dev.of_node->name);
	dev_info(&aonhsp->dev, "probed\n");

	return 0;

fail:
	if (err != -EPROBE_DEFER) {
		dev_err(&aonhsp->dev, "%s: failed to obtain : %d\n",
			np->name, err);
	}
	of_node_put(np);
	return err;
}

static const struct device_type aon_hsp_combo_dev_type = {
	.name	= "aon-hsp-protocol",
};

static void aon_hsp_combo_dev_release(struct device *dev)
{
	struct aon_hsp *aonhsp = container_of(dev, struct aon_hsp, dev);

	if (!IS_ERR_OR_NULL(aonhsp->rx.chan))
		mbox_free_channel(aonhsp->rx.chan);
	if (!IS_ERR_OR_NULL(aonhsp->tx.chan))
		mbox_free_channel(aonhsp->tx.chan);

	of_node_put(dev->of_node);
	kfree(aonhsp);
}

static void aon_hsp_free(struct aon_hsp *aonhsp)
{
	if (IS_ERR_OR_NULL(aonhsp))
		return;

	if (dev_get_drvdata(&aonhsp->dev) != NULL)
		device_unregister(&aonhsp->dev);
	else
		put_device(&aonhsp->dev);
}

static struct aon_hsp *aon_hsp_create(struct device *dev,
				void (*full_notify)(void *data, u32 value),
				void *pdata)
{
	struct aon_hsp *aonhsp;
	int ret = -EINVAL;

	aonhsp = kzalloc(sizeof(*aonhsp), GFP_KERNEL);
	if (aonhsp == NULL)
		return ERR_PTR(-ENOMEM);

	aonhsp->dev.parent = dev;
	aonhsp->full_notify = full_notify;
	aonhsp->pdata = pdata;

	init_completion(&aonhsp->emptied);

	aonhsp->dev.type = &aon_hsp_combo_dev_type;
	aonhsp->dev.release = aon_hsp_combo_dev_release;
	device_initialize(&aonhsp->dev);

	dev_set_name(&aonhsp->dev, "%s:%s", dev_name(dev), "hsp");

	aonhsp->tx.client.tx_block = false;
	aonhsp->rx.client.rx_callback = aon_hsp_rx_full_notify;
	aonhsp->tx.client.tx_done = aon_hsp_tx_empty_notify;
	aonhsp->rx.client.dev = aonhsp->tx.client.dev = &(aonhsp->dev);

	ret = aon_hsp_probe(aonhsp);
	if (ret < 0)
		goto fail;

	ret = device_add(&aonhsp->dev);
	if (ret < 0)
		goto fail;

	dev_set_drvdata(&aonhsp->dev, aonhsp);

	return aonhsp;

fail:
	aon_hsp_free(aonhsp);
	return ERR_PTR(ret);
}

bool tegra_aon_hsp_sm_tx_is_empty(struct tegra_aon *aon)
{
	struct aon_hsp *aonhsp = aon->hsp;

	return try_wait_for_completion(&aonhsp->emptied);
}

int tegra_aon_hsp_sm_tx_write(struct tegra_aon *aon, u32 value)
{
	struct aon_hsp *aonhsp = aon->hsp;

	return mbox_send_message(aonhsp->tx.chan,
				 (void *) (unsigned long) value);
}

int tegra_aon_hsp_sm_pair_request(struct tegra_aon *aon,
				  void (*full_notify)(void *data, u32 value),
				  void *pdata)
{
	struct device_node *hsp_node;
	struct device *dev = aon->dev;
	struct device_node *dn = dev->of_node;

	hsp_node = of_get_child_by_name(dn, "hsp");
	if (hsp_node == NULL) {
		dev_err(dev, "No hsp child node for AON\n");
		return -ENODEV;
	}

	aon->hsp = aon_hsp_create(dev, full_notify, pdata);
	if (IS_ERR(aon->hsp)) {
		aon->hsp = NULL;
		return PTR_ERR(aon->hsp);
	}

	return 0;
}

void tegra_aon_hsp_sm_pair_free(struct tegra_aon *aon)
{
	if (!IS_ERR_OR_NULL(aon) && !IS_ERR_OR_NULL(aon->hsp)) {
		aon_hsp_free(aon->hsp);
		aon->hsp = NULL;
	}
}