/*
 * AMD Platform Security Processor (PSP) interface
 *
 * Copyright (C) 2016-2017 Advanced Micro Devices, Inc.
 *
 * Author: Brijesh Singh <brijesh.singh@amd.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/spinlock_types.h>
#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/hw_random.h>
#include <linux/ccp.h>

#include "sp-dev.h"
#include "psp-dev.h"

static struct psp_device *psp_alloc_struct(struct sp_device *sp)
{
	struct device *dev = sp->dev;
	struct psp_device *psp;

	psp = devm_kzalloc(dev, sizeof(*psp), GFP_KERNEL);
	if (!psp)
		return NULL;

	psp->dev = dev;
	psp->sp = sp;

	snprintf(psp->name, sizeof(psp->name), "psp-%u", sp->ord);

	return psp;
}

static irqreturn_t psp_irq_handler(int irq, void *data)
{
	return IRQ_HANDLED;
}

int psp_dev_init(struct sp_device *sp)
{
	struct device *dev = sp->dev;
	struct psp_device *psp;
	int ret;

	ret = -ENOMEM;
	psp = psp_alloc_struct(sp);
	if (!psp)
		goto e_err;

	sp->psp_data = psp;

	psp->vdata = (struct psp_vdata *)sp->dev_vdata->psp_vdata;
	if (!psp->vdata) {
		ret = -ENODEV;
		dev_err(dev, "missing driver data\n");
		goto e_err;
	}

	psp->io_regs = sp->io_map + psp->vdata->offset;

	/* Disable and clear interrupts until ready */
	iowrite32(0, psp->io_regs + PSP_P2CMSG_INTEN);
	iowrite32(-1, psp->io_regs + PSP_P2CMSG_INTSTS);

	/* Request an irq */
	ret = sp_request_psp_irq(psp->sp, psp_irq_handler, psp->name, psp);
	if (ret) {
		dev_err(dev, "psp: unable to allocate an IRQ\n");
		goto e_err;
	}

	if (sp->set_psp_master_device)
		sp->set_psp_master_device(sp);

	/* Enable interrupt */
	iowrite32(-1, psp->io_regs + PSP_P2CMSG_INTEN);

	return 0;

e_err:
	sp->psp_data = NULL;

	dev_notice(dev, "psp initialization failed\n");

	return ret;
}

void psp_dev_destroy(struct sp_device *sp)
{
	struct psp_device *psp = sp->psp_data;

	sp_free_psp_irq(sp, psp);
}