/*
 * Broadcom PCIe 1570 webcam driver
 *
 * Copyright (C) 2014 Patrik Jakobsson (patrik.r.jakobsson@gmail.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/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/io.h>
#include <linux/interrupt.h>
#include <linux/workqueue.h>
#include "bcwc_drv.h"

static int bcwc_pci_reserve_mem(struct bcwc_private *dev_priv)
{
	unsigned long start;
	unsigned long len;
	int ret;

	/* Reserve resources */
	ret = pci_request_region(dev_priv->pdev, BCWC_PCI_LINK_IO, "Link IO");
	if (ret) {
		dev_err(&dev_priv->pdev->dev, "Failed to request Link IO\n");
		return ret;
	}

	ret = pci_request_region(dev_priv->pdev, BCWC_PCI_DEV_IO, "Device IO");
	if (ret) {
		dev_err(&dev_priv->pdev->dev, "Failed to request Device IO\n");
		return ret;
	}

	/* Link IO */
	start = pci_resource_start(dev_priv->pdev, BCWC_PCI_LINK_IO);
	len = pci_resource_len(dev_priv->pdev, BCWC_PCI_LINK_IO);
	dev_priv->link_io = ioremap_nocache(start, len);
	dev_priv->link_io_len = len;

	/* Device IO */
	start = pci_resource_start(dev_priv->pdev, BCWC_PCI_DEV_IO);
	len = pci_resource_len(dev_priv->pdev, BCWC_PCI_DEV_IO);
	dev_priv->dev_io = ioremap_nocache(start, len);
	dev_priv->dev_io_len = len;

	return 0;
}

static void bcwc_irq_work(struct work_struct *work)
{
}

static irqreturn_t bcwc_irq_handler(int irq, void *arg)
{
	struct bcwc_private *dev_priv = arg;

	schedule_work(&dev_priv->irq_work);

	return IRQ_HANDLED;
}

static int bcwc_irq_enable(struct bcwc_private *dev_priv)
{
	int ret;

	ret = request_irq(dev_priv->pdev->irq, bcwc_irq_handler, IRQF_SHARED,
			  KBUILD_MODNAME, (void *)dev_priv);

	if (ret)
		dev_err(&dev_priv->pdev->dev, "Failed to request IRQ\n");

	return ret;
}

static void bcwc_irq_disable(struct bcwc_private *dev_priv)
{
	free_irq(dev_priv->pdev->irq, dev_priv);
}

static int bcwc_pci_set_dma_mask(struct bcwc_private *dev_priv,
				 unsigned int mask)
{
	int ret;

	ret = pci_set_dma_mask(dev_priv->pdev, DMA_BIT_MASK(mask));
	if (ret) {
		dev_err(&dev_priv->pdev->dev, "Failed to set %u pci dma mask\n",
			mask);
		return ret;
	}

	dev_priv->dma_mask = mask;

	return 0;
}

static int bcwc_pci_probe(struct pci_dev *pdev,
			  const struct pci_device_id *entry)
{
	struct bcwc_private *dev_priv;
	int ret;

	dev_info(&pdev->dev, "Found Broadcom PCIe webcam with device id: %x\n",
		 pdev->device);

	dev_priv = kzalloc(sizeof(struct bcwc_private), GFP_KERNEL);
	if (!dev_priv) {
		dev_err(&pdev->dev, "Failed to allocate memory\n");
		return -ENOMEM;
	}

	dev_priv->pdev = pdev;

	ret = pci_enable_device(pdev);
	if (ret) {
		dev_err(&pdev->dev, "Failed to enable device\n");
		goto fail_free;
	}

	ret = bcwc_pci_reserve_mem(dev_priv);
	if (ret)
		goto fail_enable;

	ret = pci_enable_msi(pdev);
	if (ret) {
		dev_err(&pdev->dev, "Failed to enable MSI\n");
		goto fail_enable;
	}

	INIT_WORK(&dev_priv->irq_work, bcwc_irq_work);

	ret = bcwc_irq_enable(dev_priv);
	if (ret)
		goto fail_msi;

	ret = bcwc_pci_set_dma_mask(dev_priv, 64);
	if (ret)
		ret = bcwc_pci_set_dma_mask(dev_priv, 32);

	if (ret)
		goto fail_msi;

	dev_info(&pdev->dev, "Setting %ubit DMA mask\n", dev_priv->dma_mask);
	pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(dev_priv->dma_mask));

	pci_set_master(pdev);
	pci_set_drvdata(pdev, dev_priv);

	return 0;
fail_msi:
	pci_disable_msi(pdev);
fail_enable:
	pci_disable_device(pdev);
fail_free:
	kfree(dev_priv);
	return ret;
}

static void bcwc_pci_remove(struct pci_dev *pdev)
{
	struct bcwc_private *dev_priv;

	dev_priv = pci_get_drvdata(pdev);

	if (dev_priv) {
		bcwc_irq_disable(dev_priv);
		pci_disable_msi(pdev);

		if (dev_priv->link_io)
			iounmap(dev_priv->link_io);
		if (dev_priv->dev_io)
			iounmap(dev_priv->dev_io);

		pci_release_region(pdev, BCWC_PCI_DEV_IO);
		pci_release_region(pdev, BCWC_PCI_LINK_IO);
	}

	pci_disable_device(pdev);
}

#ifdef CONFIG_PM
static int bcwc_pci_suspend(struct pci_dev *pdev, pm_message_t state)
{
	return 0;
}

static int bcwc_pci_resume(struct pci_dev *pdev)
{
	return 0;
}
#endif /* CONFIG_PM */

static const struct pci_device_id bcwc_pci_id_table[] = {
	{ PCI_VDEVICE(BROADCOM, 0x1570), 4 },
	{ 0, },
};

static struct pci_driver bcwc_pci_driver = {
	.name = KBUILD_MODNAME,
	.probe = bcwc_pci_probe,
	.remove = bcwc_pci_remove,
	.id_table = bcwc_pci_id_table,
#ifdef CONFIG_PM
	.suspend = bcwc_pci_suspend,
	.resume = bcwc_pci_resume,
#endif
};

static int __init bcwc_init(void)
{
	int ret = 0;

	ret = pci_register_driver(&bcwc_pci_driver);

	if (ret)
		pr_err("Couldn't find any devices (ret=%d)\n", ret);

	return ret;
}

static void __exit bcwc_exit(void)
{
	pci_unregister_driver(&bcwc_pci_driver);
}

module_init(bcwc_init);
module_exit(bcwc_exit);

MODULE_AUTHOR("Patrik Jakobsson <patrik.r.jakobsson@gmail.com>");
MODULE_DESCRIPTION("Broadcom PCIe 1570 webcam driver");
MODULE_LICENSE("GPL");