linux/drivers/mfd/vx855.c
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   1/*
   2 * Linux multi-function-device driver (MFD) for the integrated peripherals
   3 * of the VIA VX855 chipset
   4 *
   5 * Copyright (C) 2009 VIA Technologies, Inc.
   6 * Copyright (C) 2010 One Laptop per Child
   7 * Author: Harald Welte <HaraldWelte@viatech.com>
   8 * All rights reserved.
   9 *
  10 * This program is free software; you can redistribute it and/or
  11 * modify it under the terms of the GNU General Public License as
  12 * published by the Free Software Foundation; either version 2 of
  13 * the License, or (at your option) any later version.
  14 *
  15 * This program is distributed in the hope that it will be useful,
  16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 * GNU General Public License for more details.
  19 *
  20 * You should have received a copy of the GNU General Public License
  21 * along with this program; if not, write to the Free Software
  22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  23 * MA 02111-1307 USA
  24 *
  25 */
  26
  27#include <linux/kernel.h>
  28#include <linux/module.h>
  29#include <linux/device.h>
  30#include <linux/platform_device.h>
  31#include <linux/pci.h>
  32#include <linux/mfd/core.h>
  33
  34/* offset into pci config space indicating the 16bit register containing
  35 * the power management IO space base */
  36#define VX855_CFG_PMIO_OFFSET   0x88
  37
  38/* ACPI I/O Space registers */
  39#define VX855_PMIO_ACPI         0x00
  40#define VX855_PMIO_ACPI_LEN     0x0b
  41
  42/* Processor Power Management */
  43#define VX855_PMIO_PPM          0x10
  44#define VX855_PMIO_PPM_LEN      0x08
  45
  46/* General Purpose Power Management */
  47#define VX855_PMIO_GPPM         0x20
  48#define VX855_PMIO_R_GPI        0x48
  49#define VX855_PMIO_R_GPO        0x4c
  50#define VX855_PMIO_GPPM_LEN     0x33
  51
  52#define VSPIC_MMIO_SIZE 0x1000
  53
  54static struct resource vx855_gpio_resources[] = {
  55        {
  56                .flags = IORESOURCE_IO,
  57        },
  58        {
  59                .flags = IORESOURCE_IO,
  60        },
  61};
  62
  63static struct mfd_cell vx855_cells[] = {
  64        {
  65                .name = "vx855_gpio",
  66                .num_resources = ARRAY_SIZE(vx855_gpio_resources),
  67                .resources = vx855_gpio_resources,
  68
  69                /* we must ignore resource conflicts, for reasons outlined in
  70                 * the vx855_gpio driver */
  71                .ignore_resource_conflicts = true,
  72        },
  73};
  74
  75static int vx855_probe(struct pci_dev *pdev,
  76                                 const struct pci_device_id *id)
  77{
  78        int ret;
  79        u16 gpio_io_offset;
  80
  81        ret = pci_enable_device(pdev);
  82        if (ret)
  83                return -ENODEV;
  84
  85        pci_read_config_word(pdev, VX855_CFG_PMIO_OFFSET, &gpio_io_offset);
  86        if (!gpio_io_offset) {
  87                dev_warn(&pdev->dev,
  88                        "BIOS did not assign PMIO base offset?!?\n");
  89                ret = -ENODEV;
  90                goto out;
  91        }
  92
  93        /* mask out the lowest seven bits, as they are always zero, but
  94         * hardware returns them as 0x01 */
  95        gpio_io_offset &= 0xff80;
  96
  97        /* As the region identified here includes many non-GPIO things, we
  98         * only work with the specific registers that concern us. */
  99        vx855_gpio_resources[0].start = gpio_io_offset + VX855_PMIO_R_GPI;
 100        vx855_gpio_resources[0].end = vx855_gpio_resources[0].start + 3;
 101        vx855_gpio_resources[1].start = gpio_io_offset + VX855_PMIO_R_GPO;
 102        vx855_gpio_resources[1].end = vx855_gpio_resources[1].start + 3;
 103
 104        ret = mfd_add_devices(&pdev->dev, -1, vx855_cells, ARRAY_SIZE(vx855_cells),
 105                        NULL, 0, NULL);
 106
 107        /* we always return -ENODEV here in order to enable other
 108         * drivers like old, not-yet-platform_device ported i2c-viapro */
 109        return -ENODEV;
 110out:
 111        pci_disable_device(pdev);
 112        return ret;
 113}
 114
 115static void vx855_remove(struct pci_dev *pdev)
 116{
 117        mfd_remove_devices(&pdev->dev);
 118        pci_disable_device(pdev);
 119}
 120
 121static DEFINE_PCI_DEVICE_TABLE(vx855_pci_tbl) = {
 122        { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX855) },
 123        { 0, }
 124};
 125MODULE_DEVICE_TABLE(pci, vx855_pci_tbl);
 126
 127static struct pci_driver vx855_pci_driver = {
 128        .name           = "vx855",
 129        .id_table       = vx855_pci_tbl,
 130        .probe          = vx855_probe,
 131        .remove         = vx855_remove,
 132};
 133
 134module_pci_driver(vx855_pci_driver);
 135
 136MODULE_LICENSE("GPL");
 137MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>");
 138MODULE_DESCRIPTION("Driver for the VIA VX855 chipset");
 139
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