/* Copyright (c) 2013-2016, 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/kernel.h>
#include <linux/module.h>
#include <linux/export.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/of_device.h>
#include <soc/qcom/jtag.h>

#define fuse_writel(drvdata, val, off)	__raw_writel((val), drvdata->base + off)
#define fuse_readl(drvdata, off)	__raw_readl(drvdata->base + off)

#define OEM_CONFIG0			(0x000)
#define OEM_CONFIG1			(0x004)
#define OEM_CONFIG2			(0x008)

/* JTAG FUSE V1 */
#define ALL_DEBUG_DISABLE		BIT(21)
#define APPS_DBGEN_DISABLE		BIT(0)
#define APPS_NIDEN_DISABLE		BIT(1)
#define APPS_SPIDEN_DISABLE		BIT(2)
#define APPS_SPNIDEN_DISABLE		BIT(3)
#define DAP_DEVICEEN_DISABLE		BIT(8)

/* JTAG FUSE V2 */
#define ALL_DEBUG_DISABLE_V2		BIT(0)
#define APPS_DBGEN_DISABLE_V2		BIT(10)
#define APPS_NIDEN_DISABLE_V2		BIT(11)
#define APPS_SPIDEN_DISABLE_V2		BIT(12)
#define APPS_SPNIDEN_DISABLE_V2	BIT(13)
#define DAP_DEVICEEN_DISABLE_V2	BIT(18)

/* JTAG FUSE V3 */
#define ALL_DEBUG_DISABLE_V3		BIT(29)
#define APPS_DBGEN_DISABLE_V3		BIT(8)
#define APPS_NIDEN_DISABLE_V3		BIT(21)
#define APPS_SPIDEN_DISABLE_V3		BIT(5)
#define APPS_SPNIDEN_DISABLE_V3	BIT(31)
#define DAP_DEVICEEN_DISABLE_V3	BIT(7)

#define JTAG_FUSE_VERSION_V1		"qcom,jtag-fuse"
#define JTAG_FUSE_VERSION_V2		"qcom,jtag-fuse-v2"
#define JTAG_FUSE_VERSION_V3		"qcom,jtag-fuse-v3"

struct fuse_drvdata {
	void __iomem		*base;
	struct device		*dev;
	bool			fuse_v2;
	bool			fuse_v3;
};

static struct fuse_drvdata *fusedrvdata;

bool msm_jtag_fuse_apps_access_disabled(void)
{
	struct fuse_drvdata *drvdata = fusedrvdata;
	uint32_t config0, config1, config2;
	bool ret = false;

	if (!drvdata)
		return false;

	config0 = fuse_readl(drvdata, OEM_CONFIG0);
	config1 = fuse_readl(drvdata, OEM_CONFIG1);

	dev_dbg(drvdata->dev, "apps config0: %lx\n", (unsigned long)config0);
	dev_dbg(drvdata->dev, "apps config1: %lx\n", (unsigned long)config1);

	if (drvdata->fuse_v3) {
		config2 = fuse_readl(drvdata, OEM_CONFIG2);
		dev_dbg(drvdata->dev, "apps config2: %lx\n",
		       (unsigned long)config2);
	}

	if (drvdata->fuse_v3) {
		if (config0 & ALL_DEBUG_DISABLE_V3)
			ret = true;
		else if (config1 & APPS_DBGEN_DISABLE_V3)
			ret = true;
		else if (config1 & APPS_NIDEN_DISABLE_V3)
			ret = true;
		else if (config2 & APPS_SPIDEN_DISABLE_V3)
			ret = true;
		else if (config1 & APPS_SPNIDEN_DISABLE_V3)
			ret = true;
		else if (config1 & DAP_DEVICEEN_DISABLE_V3)
			ret = true;
	} else if (drvdata->fuse_v2) {
		if (config1 & ALL_DEBUG_DISABLE_V2)
			ret = true;
		else if (config1 & APPS_DBGEN_DISABLE_V2)
			ret = true;
		else if (config1 & APPS_NIDEN_DISABLE_V2)
			ret = true;
		else if (config1 & APPS_SPIDEN_DISABLE_V2)
			ret = true;
		else if (config1 & APPS_SPNIDEN_DISABLE_V2)
			ret = true;
		else if (config1 & DAP_DEVICEEN_DISABLE_V2)
			ret = true;
	} else {
		if (config0 & ALL_DEBUG_DISABLE)
			ret = true;
		else if (config1 & APPS_DBGEN_DISABLE)
			ret = true;
		else if (config1 & APPS_NIDEN_DISABLE)
			ret = true;
		else if (config1 & APPS_SPIDEN_DISABLE)
			ret = true;
		else if (config1 & APPS_SPNIDEN_DISABLE)
			ret = true;
		else if (config1 & DAP_DEVICEEN_DISABLE)
			ret = true;
	}

	if (ret)
		dev_dbg(drvdata->dev, "apps fuse disabled\n");

	return ret;
}
EXPORT_SYMBOL(msm_jtag_fuse_apps_access_disabled);

static struct of_device_id jtag_fuse_match[] = {
	{.compatible = JTAG_FUSE_VERSION_V1 },
	{.compatible = JTAG_FUSE_VERSION_V2 },
	{.compatible = JTAG_FUSE_VERSION_V3 },
	{}
};

static int jtag_fuse_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct fuse_drvdata *drvdata;
	struct resource *res;
	const struct of_device_id *match;

	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
	if (!drvdata)
		return -ENOMEM;
	drvdata->dev = &pdev->dev;
	platform_set_drvdata(pdev, drvdata);

	match = of_match_device(jtag_fuse_match, dev);
	if (!match)
		return -EINVAL;

	if (!strcmp(match->compatible, JTAG_FUSE_VERSION_V2))
		drvdata->fuse_v2 = true;
	else if (!strcmp(match->compatible, JTAG_FUSE_VERSION_V3))
		drvdata->fuse_v3 = true;

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "fuse-base");
	if (!res)
		return -ENODEV;

	drvdata->base = devm_ioremap(dev, res->start, resource_size(res));
	if (!drvdata->base)
		return -ENOMEM;

	/* Store the driver data pointer for use in exported functions */
	fusedrvdata = drvdata;
	dev_info(dev, "JTag Fuse initialized\n");
	return 0;
}

static int jtag_fuse_remove(struct platform_device *pdev)
{
	return 0;
}

static struct platform_driver jtag_fuse_driver = {
	.probe          = jtag_fuse_probe,
	.remove         = jtag_fuse_remove,
	.driver         = {
		.name   = "msm-jtag-fuse",
		.owner	= THIS_MODULE,
		.of_match_table = jtag_fuse_match,
	},
};

static int __init jtag_fuse_init(void)
{
	return platform_driver_register(&jtag_fuse_driver);
}
arch_initcall(jtag_fuse_init);

static void __exit jtag_fuse_exit(void)
{
	platform_driver_unregister(&jtag_fuse_driver);
}
module_exit(jtag_fuse_exit);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("JTag Fuse driver");