/*
 * Samsung TZIC Driver
 *
 * 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.
 */

#define KMSG_COMPONENT "TZIC"

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/platform_device.h>
#include <linux/debugfs.h>
#include <linux/cdev.h>
#include <linux/uaccess.h>
#include <linux/sched.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/io.h>
#include <linux/types.h>
#include <asm/smc.h>

#define TZIC_DEV "tzic"
#define SMC_CMD_STORE_BINFO	 (-201)

static int gotoCpu0(void);
static int gotoAllCpu(void) __attribute__ ((unused));

u32 exynos_smc1(u32 cmd, u32 arg1, u32 arg2, u32 arg3)
{
	register u32 reg0 __asm__("r0") = cmd;
	register u32 reg1 __asm__("r1") = arg1;
	register u32 reg2 __asm__("r2") = arg2;
	register u32 reg3 __asm__("r3") = arg3;

	__asm__ volatile (
#ifdef REQUIRES_SEC
		".arch_extension sec\n"
#endif
		"smc	0\n"
		: "+r"(reg0), "+r"(reg1), "+r"(reg2), "+r"(reg3)
	);

	return reg0;
}

#if defined(CONFIG_FELICA)
int exynos_smc_read_oemflag(u32 ctrl_word, u32 *val)
{
	register u32 reg0 __asm__("r0");
	register u32 reg1 __asm__("r1");
	register u32 reg2 __asm__("r2");
	register u32 reg3 __asm__("r3");
	u32 idx = 0;

	for (idx = 0; reg2 != ctrl_word; idx++) {
		reg0 = -202;
		reg1 = 1;
		reg2 = idx;

		__asm__ volatile (
#ifdef REQUIRES_SEC
			".arch_extension sec\n"
#endif
			"smc    0\n"
			:"+r" (reg0), "+r"(reg1),
				  "+r"(reg2), "+r"(reg3)
		    );
		if (reg1)
			return -1;
	}

	reg0 = -202;
	reg1 = 1;
	reg2 = idx;

	__asm__ volatile (
#ifdef REQUIRES_SEC
			".arch_extension sec\n"
#endif
			"smc    0\n"
			:"+r" (reg0), "+r"(reg1), "+r"(reg2),
			  "+r"(reg3)
	    );
	if (reg1)
		return -1;

	*val = reg2;

	return 0;
}
#endif

static DEFINE_MUTEX(tzic_mutex);
static struct class *driver_class;
static dev_t tzic_device_no;
static struct cdev tzic_cdev;

#define LOG printk
#define TZIC_IOC_MAGIC 0x9E
#define TZIC_IOCTL_SET_FUSE_REQ _IO(TZIC_IOC_MAGIC, 1)
#define TZIC_IOCTL_GET_FUSE_REQ _IOR(TZIC_IOC_MAGIC, 0, unsigned int)

static long tzic_ioctl(struct file *file, unsigned cmd, unsigned long arg)
{
	int ret = 0;

	ret = gotoCpu0();
	if (0 != ret) {
		LOG(KERN_INFO "changing core failed!");
		return -1;
	}

	if (cmd == TZIC_IOCTL_SET_FUSE_REQ) {
		LOG(KERN_INFO "set_fuse");
		exynos_smc1(SMC_CMD_STORE_BINFO, 0x80010001, 0, 0);
		exynos_smc1(SMC_CMD_STORE_BINFO, 0x00000001, 0, 0);
	} else if (cmd == TZIC_IOCTL_GET_FUSE_REQ) {
		LOG(KERN_INFO "get_fuse");
#if defined(CONFIG_FELICA)
		exynos_smc_read_oemflag(0x80010001, (u32 *) arg);
#else
		LOG(KERN_INFO "get_fuse not supported : CONFIG_FELICA");
#endif
	} else {
		LOG(KERN_INFO "command error");
	}

	gotoAllCpu();

	return 0;
}

static const struct file_operations tzic_fops = {
	.owner = THIS_MODULE,
	.unlocked_ioctl = tzic_ioctl,
};

static int __init tzic_init(void)
{
	int rc;
	struct device *class_dev;

	rc = alloc_chrdev_region(&tzic_device_no, 0, 1, TZIC_DEV);
	if (rc < 0) {
		LOG(KERN_INFO "alloc_chrdev_region failed %d", rc);
		return rc;
	}

	driver_class = class_create(THIS_MODULE, TZIC_DEV);
	if (IS_ERR(driver_class)) {
		rc = -ENOMEM;
		LOG(KERN_INFO "class_create failed %d", rc);
		goto unregister_chrdev_region;
	}

	class_dev = device_create(driver_class, NULL, tzic_device_no, NULL,
				  TZIC_DEV);
	if (!class_dev) {
		LOG(KERN_INFO "class_device_create failed %d", rc);
		rc = -ENOMEM;
		goto class_destroy;
	}

	cdev_init(&tzic_cdev, &tzic_fops);
	tzic_cdev.owner = THIS_MODULE;

	rc = cdev_add(&tzic_cdev, MKDEV(MAJOR(tzic_device_no), 0), 1);
	if (rc < 0) {
		LOG(KERN_INFO "cdev_add failed %d", rc);
		goto class_device_destroy;
	}

	return 0;

 class_device_destroy:
	device_destroy(driver_class, tzic_device_no);
 class_destroy:
	class_destroy(driver_class);
 unregister_chrdev_region:
	unregister_chrdev_region(tzic_device_no, 1);
	return rc;
}

static void __exit tzic_exit(void)
{
	device_destroy(driver_class, tzic_device_no);
	class_destroy(driver_class);
	unregister_chrdev_region(tzic_device_no, 1);
}

static int gotoCpu0(void)
{
	int ret = 0;
	struct cpumask mask = CPU_MASK_CPU0;

	LOG(KERN_INFO "System has %d CPU's, we are on CPU #%d\n"
	    "\tBinding this process to CPU #0.\n"
	    "\tactive mask is %lx, setting it to mask=%lx\n",
	    nr_cpu_ids,
	    raw_smp_processor_id(), cpu_active_mask->bits[0], mask.bits[0]);
	ret = set_cpus_allowed_ptr(current, &mask);
	if (0 != ret)
		LOG(KERN_INFO "set_cpus_allowed_ptr=%d.\n", ret);
	LOG(KERN_INFO "And now we are on CPU #%d", raw_smp_processor_id());

	return ret;
}

static int gotoAllCpu(void)
{
	int ret = 0;
	struct cpumask mask = CPU_MASK_ALL;

	LOG(KERN_INFO "System has %d CPU's, we are on CPU #%d\n"
	    "\tBinding this process to CPU #0.\n"
	    "\tactive mask is %lx, setting it to mask=%lx\n",
	    nr_cpu_ids,
	    raw_smp_processor_id(), cpu_active_mask->bits[0], mask.bits[0]);
	ret = set_cpus_allowed_ptr(current, &mask);
	if (0 != ret)
		LOG(KERN_INFO "set_cpus_allowed_ptr=%d.\n", ret);
	LOG(KERN_INFO "And now we are on CPU #%d", raw_smp_processor_id());

	return ret;
}

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Samsung TZIC Driver");
MODULE_VERSION("1.00");

module_init(tzic_init);
module_exit(tzic_exit);