/*
 * Copyright (C) 2007, 2011 Wolfgang Grandegger <wg@grandegger.com>
 *
 * Derived from the PCAN project file driver/src/pcan_pci.c:
 *
 * Copyright (C) 2001-2006  PEAK System-Technik GmbH
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the version 2 of the GNU General Public License
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>
#include <linux/delay.h>
#include <linux/pci.h>
#include <linux/io.h>
#include <linux/can.h>
#include <linux/can/dev.h>

#include "sja1000.h"

MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
MODULE_DESCRIPTION("Socket-CAN driver for PEAK PCAN PCI/PCIe cards");
MODULE_SUPPORTED_DEVICE("PEAK PCAN PCI/PCIe CAN card");
MODULE_LICENSE("GPL v2");

#define DRV_NAME  "peak_pci"

struct peak_pci_chan {
	void __iomem *cfg_base;		/* Common for all channels */
	struct net_device *prev_dev;	/* Chain of network devices */
	u16 icr_mask;			/* Interrupt mask for fast ack */
};

#define PEAK_PCI_CAN_CLOCK	(16000000 / 2)

#define PEAK_PCI_CDR		(CDR_CBP | CDR_CLKOUT_MASK)
#define PEAK_PCI_OCR		OCR_TX0_PUSHPULL

/*
 * Important PITA registers
 */
#define PITA_ICR		0x00	/* Interrupt control register */
#define PITA_GPIOICR		0x18	/* GPIO interface control register */
#define PITA_MISC		0x1C	/* Miscellaneous register */

#define PEAK_PCI_CFG_SIZE	0x1000	/* Size of the config PCI bar */
#define PEAK_PCI_CHAN_SIZE	0x0400	/* Size used by the channel */

#define PEAK_PCI_VENDOR_ID	0x001C	/* The PCI device and vendor IDs */
#define PEAK_PCI_DEVICE_ID	0x0001	/* for PCI/PCIe slot cards */

static const u16 peak_pci_icr_masks[] = {0x02, 0x01, 0x40, 0x80};

static DEFINE_PCI_DEVICE_TABLE(peak_pci_tbl) = {
	{PEAK_PCI_VENDOR_ID, PEAK_PCI_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
	{0,}
};

MODULE_DEVICE_TABLE(pci, peak_pci_tbl);

static u8 peak_pci_read_reg(const struct sja1000_priv *priv, int port)
{
	return readb(priv->reg_base + (port << 2));
}

static void peak_pci_write_reg(const struct sja1000_priv *priv,
			       int port, u8 val)
{
	writeb(val, priv->reg_base + (port << 2));
}

static void peak_pci_post_irq(const struct sja1000_priv *priv)
{
	struct peak_pci_chan *chan = priv->priv;
	u16 icr;

	/* Select and clear in PITA stored interrupt */
	icr = readw(chan->cfg_base + PITA_ICR);
	if (icr & chan->icr_mask)
		writew(chan->icr_mask, chan->cfg_base + PITA_ICR);
}

static int __devinit peak_pci_probe(struct pci_dev *pdev,
				    const struct pci_device_id *ent)
{
	struct sja1000_priv *priv;
	struct peak_pci_chan *chan;
	struct net_device *dev;
	void __iomem *cfg_base, *reg_base;
	u16 sub_sys_id, icr;
	int i, err, channels;

	err = pci_enable_device(pdev);
	if (err)
		return err;

	err = pci_request_regions(pdev, DRV_NAME);
	if (err)
		goto failure_disable_pci;

	err = pci_read_config_word(pdev, 0x2e, &sub_sys_id);
	if (err)
		goto failure_release_regions;

	dev_dbg(&pdev->dev, "probing device %04x:%04x:%04x\n",
		pdev->vendor, pdev->device, sub_sys_id);

	err = pci_write_config_word(pdev, 0x44, 0);
	if (err)
		goto failure_release_regions;

	if (sub_sys_id >= 12)
		channels = 4;
	else if (sub_sys_id >= 10)
		channels = 3;
	else if (sub_sys_id >= 4)
		channels = 2;
	else
		channels = 1;

	cfg_base = pci_iomap(pdev, 0, PEAK_PCI_CFG_SIZE);
	if (!cfg_base) {
		dev_err(&pdev->dev, "failed to map PCI resource #0\n");
		goto failure_release_regions;
	}

	reg_base = pci_iomap(pdev, 1, PEAK_PCI_CHAN_SIZE * channels);
	if (!reg_base) {
		dev_err(&pdev->dev, "failed to map PCI resource #1\n");
		goto failure_unmap_cfg_base;
	}

	/* Set GPIO control register */
	writew(0x0005, cfg_base + PITA_GPIOICR + 2);
	/* Enable all channels of this card */
	writeb(0x00, cfg_base + PITA_GPIOICR);
	/* Toggle reset */
	writeb(0x05, cfg_base + PITA_MISC + 3);
	mdelay(5);
	/* Leave parport mux mode */
	writeb(0x04, cfg_base + PITA_MISC + 3);

	icr = readw(cfg_base + PITA_ICR + 2);

	for (i = 0; i < channels; i++) {
		dev = alloc_sja1000dev(sizeof(struct peak_pci_chan));
		if (!dev) {
			err = -ENOMEM;
			goto failure_remove_channels;
		}

		priv = netdev_priv(dev);
		chan = priv->priv;

		chan->cfg_base = cfg_base;
		priv->reg_base = reg_base + i * PEAK_PCI_CHAN_SIZE;

		priv->read_reg = peak_pci_read_reg;
		priv->write_reg = peak_pci_write_reg;
		priv->post_irq = peak_pci_post_irq;

		priv->can.clock.freq = PEAK_PCI_CAN_CLOCK;
		priv->ocr = PEAK_PCI_OCR;
		priv->cdr = PEAK_PCI_CDR;
		/* Neither a slave nor a single device distributes the clock */
		if (channels == 1 || i > 0)
			priv->cdr |= CDR_CLK_OFF;

		/* Setup interrupt handling */
		priv->irq_flags = IRQF_SHARED;
		dev->irq = pdev->irq;

		chan->icr_mask = peak_pci_icr_masks[i];
		icr |= chan->icr_mask;

		SET_NETDEV_DEV(dev, &pdev->dev);

		err = register_sja1000dev(dev);
		if (err) {
			dev_err(&pdev->dev, "failed to register device\n");
			free_sja1000dev(dev);
			goto failure_remove_channels;
		}

		/* Create chain of SJA1000 devices */
		chan->prev_dev = pci_get_drvdata(pdev);
		pci_set_drvdata(pdev, dev);

		dev_info(&pdev->dev,
			 "%s at reg_base=0x%p cfg_base=0x%p irq=%d\n",
			 dev->name, priv->reg_base, chan->cfg_base, dev->irq);
	}

	/* Enable interrupts */
	writew(icr, cfg_base + PITA_ICR + 2);

	return 0;

failure_remove_channels:
	/* Disable interrupts */
	writew(0x0, cfg_base + PITA_ICR + 2);

	for (dev = pci_get_drvdata(pdev); dev; dev = chan->prev_dev) {
		unregister_sja1000dev(dev);
		free_sja1000dev(dev);
		priv = netdev_priv(dev);
		chan = priv->priv;
	}

	pci_iounmap(pdev, reg_base);

failure_unmap_cfg_base:
	pci_iounmap(pdev, cfg_base);

failure_release_regions:
	pci_release_regions(pdev);

failure_disable_pci:
	pci_disable_device(pdev);

	return err;
}

static void __devexit peak_pci_remove(struct pci_dev *pdev)
{
	struct net_device *dev = pci_get_drvdata(pdev); /* Last device */
	struct sja1000_priv *priv = netdev_priv(dev);
	struct peak_pci_chan *chan = priv->priv;
	void __iomem *cfg_base = chan->cfg_base;
	void __iomem *reg_base = priv->reg_base;

	/* Disable interrupts */
	writew(0x0, cfg_base + PITA_ICR + 2);

	/* Loop over all registered devices */
	while (1) {
		dev_info(&pdev->dev, "removing device %s\n", dev->name);
		unregister_sja1000dev(dev);
		free_sja1000dev(dev);
		dev = chan->prev_dev;
		if (!dev)
			break;
		priv = netdev_priv(dev);
		chan = priv->priv;
	}

	pci_iounmap(pdev, reg_base);
	pci_iounmap(pdev, cfg_base);
	pci_release_regions(pdev);
	pci_disable_device(pdev);

	pci_set_drvdata(pdev, NULL);
}

static struct pci_driver peak_pci_driver = {
	.name = DRV_NAME,
	.id_table = peak_pci_tbl,
	.probe = peak_pci_probe,
	.remove = __devexit_p(peak_pci_remove),
};

static int __init peak_pci_init(void)
{
	return pci_register_driver(&peak_pci_driver);
}
module_init(peak_pci_init);

static void __exit peak_pci_exit(void)
{
	pci_unregister_driver(&peak_pci_driver);
}
module_exit(peak_pci_exit);