vx855.c

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/*
 * Linux multi-function-device driver (MFD) for the integrated peripherals
 * of the VIA VX855 chipset
 *
 * Copyright (C) 2009 VIA Technologies, Inc.
 * Copyright (C) 2010 One Laptop per Child
 * Author: Harald Welte <[email protected]>
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * 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/device.h>
#include <linux/platform_device.h>
#include <linux/pci.h>
#include <linux/mfd/core.h>

/* offset into pci config space indicating the 16bit register containing
 * the power management IO space base */
#define VX855_CFG_PMIO_OFFSET   0x88

/* ACPI I/O Space registers */
#define VX855_PMIO_ACPI     0x00
#define VX855_PMIO_ACPI_LEN 0x0b

/* Processor Power Management */
#define VX855_PMIO_PPM      0x10
#define VX855_PMIO_PPM_LEN  0x08

/* General Purpose Power Management */
#define VX855_PMIO_GPPM     0x20
#define VX855_PMIO_R_GPI    0x48
#define VX855_PMIO_R_GPO    0x4c
#define VX855_PMIO_GPPM_LEN 0x33

#define VSPIC_MMIO_SIZE 0x1000

static struct resource vx855_gpio_resources[] = {
    {
        .flags = IORESOURCE_IO,
    },
    {
        .flags = IORESOURCE_IO,
    },
};

static struct mfd_cell vx855_cells[] = {
    {
        .name = "vx855_gpio",
        .num_resources = ARRAY_SIZE(vx855_gpio_resources),
        .resources = vx855_gpio_resources,

        /* we must ignore resource conflicts, for reasons outlined in
         * the vx855_gpio driver */
        .ignore_resource_conflicts = true,
    },
};

static __devinit int vx855_probe(struct pci_dev *pdev,
                 const struct pci_device_id *id)
{
    int ret;
    u16 gpio_io_offset;

    ret = pci_enable_device(pdev);
    if (ret)
        return -ENODEV;

    pci_read_config_word(pdev, VX855_CFG_PMIO_OFFSET, &gpio_io_offset);
    if (!gpio_io_offset) {
        dev_warn(&pdev->dev,
            "BIOS did not assign PMIO base offset?!?\n");
        ret = -ENODEV;
        goto out;
    }

    /* mask out the lowest seven bits, as they are always zero, but
     * hardware returns them as 0x01 */
    gpio_io_offset &= 0xff80;

    /* As the region identified here includes many non-GPIO things, we
     * only work with the specific registers that concern us. */
    vx855_gpio_resources[0].start = gpio_io_offset + VX855_PMIO_R_GPI;
    vx855_gpio_resources[0].end = vx855_gpio_resources[0].start + 3;
    vx855_gpio_resources[1].start = gpio_io_offset + VX855_PMIO_R_GPO;
    vx855_gpio_resources[1].end = vx855_gpio_resources[1].start + 3;

    ret = mfd_add_devices(&pdev->dev, -1, vx855_cells, ARRAY_SIZE(vx855_cells),
            NULL, 0, NULL);

    /* we always return -ENODEV here in order to enable other
     * drivers like old, not-yet-platform_device ported i2c-viapro */
    return -ENODEV;
out:
    pci_disable_device(pdev);
    return ret;
}

static void __devexit vx855_remove(struct pci_dev *pdev)
{
    mfd_remove_devices(&pdev->dev);
    pci_disable_device(pdev);
}

static DEFINE_PCI_DEVICE_TABLE(vx855_pci_tbl) = {
    { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX855) },
    { 0, }
};
MODULE_DEVICE_TABLE(pci, vx855_pci_tbl);

static struct pci_driver vx855_pci_driver = {
    .name       = "vx855",
    .id_table   = vx855_pci_tbl,
    .probe      = vx855_probe,
    .remove     = __devexit_p(vx855_remove),
};

module_pci_driver(vx855_pci_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Harald Welte <[email protected]>");
MODULE_DESCRIPTION("Driver for the VIA VX855 chipset");