/*
 * Copyright 2013 Freescale Semiconductor, Inc.
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/io.h>
#include <linux/uio_driver.h>
#include <linux/slab.h>
#include <linux/list.h>
#include "regs.h"
#include "fsl_jr_uio.h"

static const char jr_uio_version[] = "fsl JR UIO driver v1.0";

#define NAME_LENGTH 30
#define JR_INDEX_OFFSET 12

static const char uio_device_name[] = "fsl-jr";
static LIST_HEAD(jr_list);

struct jr_uio_info {
	atomic_t ref; /* exclusive, only one open() at a time */
	struct uio_info uio;
	char name[NAME_LENGTH];
};

struct jr_dev {
	u32 revision;
	u32 index;
	u32 irq;
	struct caam_job_ring __iomem *global_regs;
	struct device *dev;
	struct resource *res;
	struct jr_uio_info info;
	struct list_head node;
	struct list_head jr_list;
};

static int jr_uio_open(struct uio_info *info, struct inode *inode)
{
	struct jr_uio_info *uio_info = container_of(info,
					struct jr_uio_info, uio);

	if (!atomic_dec_and_test(&uio_info->ref)) {
		pr_err("%s: failing non-exclusive open()\n", uio_info->name);
		atomic_inc(&uio_info->ref);
		return -EBUSY;
	}

	return 0;
}

static int jr_uio_release(struct uio_info *info, struct inode *inode)
{
	struct jr_uio_info *uio_info = container_of(info,
					struct jr_uio_info, uio);
	atomic_inc(&uio_info->ref);

	return 0;
}

static irqreturn_t jr_uio_irq_handler(int irq, struct uio_info *dev_info)
{
	struct jr_dev *jrdev = dev_info->priv;
	u32 irqstate;
	irqstate = rd_reg32(&jrdev->global_regs->jrintstatus);
	if (!irqstate) {
		return IRQ_NONE;
	}

	if (irqstate & JRINT_JR_ERROR)
		dev_info(jrdev->dev, "uio job ring error - irqstate: %08x\n",
			 irqstate);

	/*mask valid interrupts */
	setbits32(&jrdev->global_regs->rconfig_lo, JRCFG_IMSK);

	/* Have valid interrupt at this point, just ACK and trigger */
	wr_reg32(&jrdev->global_regs->jrintstatus, irqstate);

	return IRQ_HANDLED;
}

static int jr_uio_irqcontrol(struct uio_info *dev_info, int irqon)
{
	struct jr_dev *jrdev = dev_info->priv;

	switch (irqon) {
	case SEC_UIO_SIMULATE_IRQ_CMD:
		uio_event_notify(dev_info);
		break;
	case SEC_UIO_ENABLE_IRQ_CMD:
		/* Enable Job Ring interrupt */
		clrbits32(&jrdev->global_regs->rconfig_lo, JRCFG_IMSK);
		break;
	case SEC_UIO_DISABLE_IRQ_CMD:
		/* Disable Job Ring interrupt */
		setbits32(&jrdev->global_regs->rconfig_lo, JRCFG_IMSK);
		break;
	default:
		break;
	}
	return 0;
}

static int __init jr_uio_init(struct jr_dev *uio_dev)
{
	int ret;
	struct jr_uio_info *info;

	info = &uio_dev->info;
	atomic_set(&info->ref, 1);
	info->uio.version = jr_uio_version;
	info->uio.name = uio_dev->info.name;
	info->uio.mem[0].name = "JR config space";
	info->uio.mem[0].addr = uio_dev->res->start;
	info->uio.mem[0].size = uio_dev->res->end - uio_dev->res->start + 1;
	info->uio.mem[0].internal_addr = uio_dev->global_regs;
	info->uio.mem[0].memtype = UIO_MEM_PHYS;
	info->uio.irq = uio_dev->irq;
	info->uio.irq_flags = IRQF_SHARED;
	info->uio.handler = jr_uio_irq_handler;
	info->uio.irqcontrol = jr_uio_irqcontrol;
	info->uio.open = jr_uio_open;
	info->uio.release = jr_uio_release;
	info->uio.priv = uio_dev;

	ret = uio_register_device(uio_dev->dev, &info->uio);
	if (ret) {
		pr_err("jr_uio: UIO registration failed\n");
		return ret;
	}

	return 0;
}

static const struct of_device_id jr_ids[] = {
	{ .compatible = "fsl,sec-v4.0-job-ring", },
	{ .compatible = "fsl,sec-v4.4-job-ring", },
	{ .compatible = "fsl,sec-v5.0-job-ring", },
	{ .compatible = "fsl,sec-v6.0-job-ring", },
	{},
};

static int fsl_jr_probe(struct platform_device *dev)
{
	struct resource regs;
	struct jr_dev *jr_dev;
	struct device_node *jr_node;
	int ret, count = 0;
	struct list_head *p;

	jr_node = dev->dev.of_node;
	if (!jr_node) {
		dev_err(&dev->dev, "Device OF-Node is NULL\n");
		return -EFAULT;
	}

	jr_dev = devm_kzalloc(&dev->dev, sizeof(struct jr_dev), GFP_KERNEL);
	if (!jr_dev) {
		dev_err(&dev->dev, "kzalloc failed\n");
		return -ENOMEM;
	}

	/* Creat name and index */
	list_for_each(p, &jr_list) {
		count++;
	}
	jr_dev->index = count;

	snprintf(jr_dev->info.name, sizeof(jr_dev->info.name) - 1,
		 "%s%d", uio_device_name, jr_dev->index);

	jr_dev->dev = &dev->dev;
	platform_set_drvdata(dev, jr_dev);

	/* Get the resource from dtb node */
	ret = of_address_to_resource(jr_node, 0, &regs);
	if (unlikely(ret < 0)) {
		dev_err(&dev->dev, "OF-Address-to-resource Failed\n");
		ret = -EFAULT;
		goto abort;
	}

	jr_dev->res = devm_request_mem_region(&dev->dev, regs.start,
			regs.end-regs.start + 1,
			jr_dev->info.name);
	if (unlikely(!jr_dev->res)) {
		dev_err(jr_dev->dev, "devm_request_mem_region failed\n");
		ret = -ENOMEM;
		goto abort;
	}

	jr_dev->global_regs = devm_ioremap(&dev->dev, jr_dev->res->start,
			jr_dev->res->end-jr_dev->res->start+1);
	if (unlikely(jr_dev->global_regs == 0)) {
		dev_err(jr_dev->dev, "devm_ioremap failed\n");
		ret = -EIO;
		goto abort;
	}
	jr_dev->irq = irq_of_parse_and_map(jr_node, 0);
	dev_dbg(jr_dev->dev, "errirq: %d\n", jr_dev->irq);

	/* Register UIO */
	ret = jr_uio_init(jr_dev);
	if (ret) {
		dev_err(&dev->dev, "UIO init Failed\n");
		goto abort;
	}

	list_add_tail(&jr_dev->node, &jr_list);

	dev_info(jr_dev->dev, "UIO device full name %s initialized\n",
		 jr_dev->info.name);

	return 0;

abort:
	return ret;
}

static int fsl_jr_remove(struct platform_device *dev)
{
	struct jr_dev *jr_dev = platform_get_drvdata(dev);

	if (!jr_dev)
		return 0;

	list_del(&jr_dev->node);
	uio_unregister_device(&jr_dev->info.uio);
	platform_set_drvdata(dev, NULL);

	return 0;
}

static struct platform_driver fsl_jr_driver = {
	.driver = {
		.name = "fsl-jr-uio",
		.owner = THIS_MODULE,
		.of_match_table = jr_ids,
	},
	.probe = fsl_jr_probe,
	.remove = fsl_jr_remove,
};

static __init int fsl_jr_init(void)
{
	int ret;

	ret = platform_driver_register(&fsl_jr_driver);
	if (unlikely(ret < 0))
		pr_warn(": %s:%hu:%s(): platform_driver_register() = %d\n",
			__FILE__, __LINE__, __func__, ret);

	return ret;
}

static void __exit fsl_jr_exit(void)
{
	platform_driver_unregister(&fsl_jr_driver);
}

module_init(fsl_jr_init);
module_exit(fsl_jr_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Ruchika Gupta <ruchika.gupta@freescale.com>");
MODULE_DESCRIPTION("FSL SEC UIO Driver");