/*
 * Copyright (C) 2008 Per Dalen <per.dalen@cnw.se>
 *
 * Parts of this software are based on (derived) the following:
 *
 * - Kvaser linux driver, version 4.72 BETA
 *   Copyright (C) 2002-2007 KVASER AB
 *
 * - Lincan driver, version 0.3.3, OCERA project
 *   Copyright (C) 2004 Pavel Pisa
 *   Copyright (C) 2001 Arnaud Westenberg
 *
 * - Socketcan SJA1000 drivers
 *   Copyright (C) 2007 Wolfgang Grandegger <wg@grandegger.com>
 *   Copyright (c) 2002-2007 Volkswagen Group Electronic Research
 *   Copyright (c) 2003 Matthias Brukner, Trajet Gmbh, Rebenring 33,
 *   38106 Braunschweig, GERMANY
 *
 * 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, see <http://www.gnu.org/licenses/>.
 */

#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/can/dev.h>
#include <linux/io.h>

#include "sja1000.h"

#define DRV_NAME  "kvaser_pci"

MODULE_AUTHOR("Per Dalen <per.dalen@cnw.se>");
MODULE_DESCRIPTION("Socket-CAN driver for KVASER PCAN PCI cards");
MODULE_SUPPORTED_DEVICE("KVASER PCAN PCI CAN card");
MODULE_LICENSE("GPL v2");

#define MAX_NO_OF_CHANNELS        4 /* max no of channels on a single card */

struct kvaser_pci {
        int channel;
        struct pci_dev *pci_dev;
        struct net_device *slave_dev[MAX_NO_OF_CHANNELS-1];
        void __iomem *conf_addr;
        void __iomem *res_addr;
        int no_channels;
        u8 xilinx_ver;
};

#define KVASER_PCI_CAN_CLOCK      (16000000 / 2)

/*
 * The board configuration is probably following:
 * RX1 is connected to ground.
 * TX1 is not connected.
 * CLKO is not connected.
 * Setting the OCR register to 0xDA is a good idea.
 * This means  normal output mode , push-pull and the correct polarity.
 */
#define KVASER_PCI_OCR            (OCR_TX0_PUSHPULL | OCR_TX1_PUSHPULL)

/*
 * In the CDR register, you should set CBP to 1.
 * You will probably also want to set the clock divider value to 0
 * (meaning divide-by-2), the Pelican bit, and the clock-off bit
 * (you will have no need for CLKOUT anyway).
 */
#define KVASER_PCI_CDR            (CDR_CBP | CDR_CLKOUT_MASK)

/*
 * These register values are valid for revision 14 of the Xilinx logic.
 */
#define XILINX_VERINT             7   /* Lower nibble simulate interrupts,
                                         high nibble version number. */

#define XILINX_PRESUMED_VERSION   14

/*
 * Important S5920 registers
 */
#define S5920_INTCSR              0x38
#define S5920_PTCR                0x60
#define INTCSR_ADDON_INTENABLE_M  0x2000


#define KVASER_PCI_PORT_BYTES     0x20

#define PCI_CONFIG_PORT_SIZE      0x80      /* size of the config io-memory */
#define PCI_PORT_SIZE             0x80      /* size of a channel io-memory */
#define PCI_PORT_XILINX_SIZE      0x08      /* size of a xilinx io-memory */

#define KVASER_PCI_VENDOR_ID1     0x10e8    /* the PCI device and vendor IDs */
#define KVASER_PCI_DEVICE_ID1     0x8406

#define KVASER_PCI_VENDOR_ID2     0x1a07    /* the PCI device and vendor IDs */
#define KVASER_PCI_DEVICE_ID2     0x0008

static const struct pci_device_id kvaser_pci_tbl[] = {
        {KVASER_PCI_VENDOR_ID1, KVASER_PCI_DEVICE_ID1, PCI_ANY_ID, PCI_ANY_ID,},
        {KVASER_PCI_VENDOR_ID2, KVASER_PCI_DEVICE_ID2, PCI_ANY_ID, PCI_ANY_ID,},
        { 0,}
};

MODULE_DEVICE_TABLE(pci, kvaser_pci_tbl);

static u8 kvaser_pci_read_reg(const struct sja1000_priv *priv, int port)
{
        return ioread8(priv->reg_base + port);
}

static void kvaser_pci_write_reg(const struct sja1000_priv *priv,
                                 int port, u8 val)
{
        iowrite8(val, priv->reg_base + port);
}

static void kvaser_pci_disable_irq(struct net_device *dev)
{
        struct sja1000_priv *priv = netdev_priv(dev);
        struct kvaser_pci *board = priv->priv;
        u32 intcsr;

        /* Disable interrupts from card */
        intcsr = ioread32(board->conf_addr + S5920_INTCSR);
        intcsr &= ~INTCSR_ADDON_INTENABLE_M;
        iowrite32(intcsr, board->conf_addr + S5920_INTCSR);
}

static void kvaser_pci_enable_irq(struct net_device *dev)
{
        struct sja1000_priv *priv = netdev_priv(dev);
        struct kvaser_pci *board = priv->priv;
        u32 tmp_en_io;

        /* Enable interrupts from card */
        tmp_en_io = ioread32(board->conf_addr + S5920_INTCSR);
        tmp_en_io |= INTCSR_ADDON_INTENABLE_M;
        iowrite32(tmp_en_io, board->conf_addr + S5920_INTCSR);
}

static int number_of_sja1000_chip(void __iomem *base_addr)
{
        u8 status;
        int i;

        for (i = 0; i < MAX_NO_OF_CHANNELS; i++) {
                /* reset chip */
                iowrite8(MOD_RM, base_addr +
                         (i * KVASER_PCI_PORT_BYTES) + SJA1000_MOD);
                status = ioread8(base_addr +
                                 (i * KVASER_PCI_PORT_BYTES) + SJA1000_MOD);
                /* check reset bit */
                if (!(status & MOD_RM))
                        break;
        }

        return i;
}

static void kvaser_pci_del_chan(struct net_device *dev)
{
        struct sja1000_priv *priv;
        struct kvaser_pci *board;
        int i;

        if (!dev)
                return;
        priv = netdev_priv(dev);
        board = priv->priv;
        if (!board)
                return;

        dev_info(&board->pci_dev->dev, "Removing device %s\n",
                 dev->name);

        /* Disable PCI interrupts */
        kvaser_pci_disable_irq(dev);

        for (i = 0; i < board->no_channels - 1; i++) {
                if (board->slave_dev[i]) {
                        dev_info(&board->pci_dev->dev, "Removing device %s\n",
                                 board->slave_dev[i]->name);
                        unregister_sja1000dev(board->slave_dev[i]);
                        free_sja1000dev(board->slave_dev[i]);
                }
        }
        unregister_sja1000dev(dev);

        pci_iounmap(board->pci_dev, priv->reg_base);
        pci_iounmap(board->pci_dev, board->conf_addr);
        pci_iounmap(board->pci_dev, board->res_addr);

        free_sja1000dev(dev);
}

static int kvaser_pci_add_chan(struct pci_dev *pdev, int channel,
                               struct net_device **master_dev,
                               void __iomem *conf_addr,
                               void __iomem *res_addr,
                               void __iomem *base_addr)
{
        struct net_device *dev;
        struct sja1000_priv *priv;
        struct kvaser_pci *board;
        int err;

        dev = alloc_sja1000dev(sizeof(struct kvaser_pci));
        if (dev == NULL)
                return -ENOMEM;

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

        board->pci_dev = pdev;
        board->channel = channel;

        /* S5920 */
        board->conf_addr = conf_addr;

        /* XILINX board wide address */
        board->res_addr = res_addr;

        if (channel == 0) {
                board->xilinx_ver =
                        ioread8(board->res_addr + XILINX_VERINT) >> 4;

                /* Assert PTADR# - we're in passive mode so the other bits are
                   not important */
                iowrite32(0x80808080UL, board->conf_addr + S5920_PTCR);

                /* Enable interrupts from card */
                kvaser_pci_enable_irq(dev);
        } else {
                struct sja1000_priv *master_priv = netdev_priv(*master_dev);
                struct kvaser_pci *master_board = master_priv->priv;
                master_board->slave_dev[channel - 1] = dev;
                master_board->no_channels = channel + 1;
                board->xilinx_ver = master_board->xilinx_ver;
        }

        priv->reg_base = base_addr + channel * KVASER_PCI_PORT_BYTES;

        priv->read_reg = kvaser_pci_read_reg;
        priv->write_reg = kvaser_pci_write_reg;

        priv->can.clock.freq = KVASER_PCI_CAN_CLOCK;

        priv->ocr = KVASER_PCI_OCR;
        priv->cdr = KVASER_PCI_CDR;

        priv->irq_flags = IRQF_SHARED;
        dev->irq = pdev->irq;

        dev_info(&pdev->dev, "reg_base=%p conf_addr=%p irq=%d\n",
                 priv->reg_base, board->conf_addr, dev->irq);

        SET_NETDEV_DEV(dev, &pdev->dev);
        dev->dev_id = channel;

        /* Register SJA1000 device */
        err = register_sja1000dev(dev);
        if (err) {
                dev_err(&pdev->dev, "Registering device failed (err=%d)\n",
                        err);
                goto failure;
        }

        if (channel == 0)
                *master_dev = dev;

        return 0;

failure:
        kvaser_pci_del_chan(dev);
        return err;
}

static int kvaser_pci_init_one(struct pci_dev *pdev,
                               const struct pci_device_id *ent)
{
        int err;
        struct net_device *master_dev = NULL;
        struct sja1000_priv *priv;
        struct kvaser_pci *board;
        int no_channels;
        void __iomem *base_addr = NULL;
        void __iomem *conf_addr = NULL;
        void __iomem *res_addr = NULL;
        int i;

        dev_info(&pdev->dev, "initializing device %04x:%04x\n",
                 pdev->vendor, pdev->device);

        err = pci_enable_device(pdev);
        if (err)
                goto failure;

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

        /* S5920 */
        conf_addr = pci_iomap(pdev, 0, PCI_CONFIG_PORT_SIZE);
        if (conf_addr == NULL) {
                err = -ENODEV;
                goto failure_release_regions;
        }

        /* XILINX board wide address */
        res_addr = pci_iomap(pdev, 2, PCI_PORT_XILINX_SIZE);
        if (res_addr == NULL) {
                err = -ENOMEM;
                goto failure_iounmap;
        }

        base_addr = pci_iomap(pdev, 1, PCI_PORT_SIZE);
        if (base_addr == NULL) {
                err = -ENOMEM;
                goto failure_iounmap;
        }

        no_channels = number_of_sja1000_chip(base_addr);
        if (no_channels == 0) {
                err = -ENOMEM;
                goto failure_iounmap;
        }

        for (i = 0; i < no_channels; i++) {
                err = kvaser_pci_add_chan(pdev, i, &master_dev,
                                          conf_addr, res_addr,
                                          base_addr);
                if (err)
                        goto failure_cleanup;
        }

        priv = netdev_priv(master_dev);
        board = priv->priv;

        dev_info(&pdev->dev, "xilinx version=%d number of channels=%d\n",
                 board->xilinx_ver, board->no_channels);

        pci_set_drvdata(pdev, master_dev);
        return 0;

failure_cleanup:
        kvaser_pci_del_chan(master_dev);

failure_iounmap:
        if (conf_addr != NULL)
                pci_iounmap(pdev, conf_addr);
        if (res_addr != NULL)
                pci_iounmap(pdev, res_addr);
        if (base_addr != NULL)
                pci_iounmap(pdev, base_addr);

failure_release_regions:
        pci_release_regions(pdev);

failure_release_pci:
        pci_disable_device(pdev);

failure:
        return err;

}

static void kvaser_pci_remove_one(struct pci_dev *pdev)
{
        struct net_device *dev = pci_get_drvdata(pdev);

        kvaser_pci_del_chan(dev);

        pci_release_regions(pdev);
        pci_disable_device(pdev);
}

static struct pci_driver kvaser_pci_driver = {
        .name = DRV_NAME,
        .id_table = kvaser_pci_tbl,
        .probe = kvaser_pci_init_one,
        .remove = kvaser_pci_remove_one,
};

module_pci_driver(kvaser_pci_driver);