LXR linux/drivers/mfd/vx855.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Linux multi-function-device driver (MFD) for the integrated peripherals
   4 * of the VIA VX855 chipset
   5 *
   6 * Copyright (C) 2009 VIA Technologies, Inc.
   7 * Copyright (C) 2010 One Laptop per Child
   8 * Author: Harald Welte <HaraldWelte@viatech.com>
   9 * All rights reserved.
  10 */
  11
  12#include <linux/kernel.h>
  13#include <linux/module.h>
  14#include <linux/device.h>
  15#include <linux/platform_device.h>
  16#include <linux/pci.h>
  17#include <linux/mfd/core.h>
  18
  19/* offset into pci config space indicating the 16bit register containing
  20 * the power management IO space base */
  21#define VX855_CFG_PMIO_OFFSET   0x88
  22
  23/* ACPI I/O Space registers */
  24#define VX855_PMIO_ACPI         0x00
  25#define VX855_PMIO_ACPI_LEN     0x0b
  26
  27/* Processor Power Management */
  28#define VX855_PMIO_PPM          0x10
  29#define VX855_PMIO_PPM_LEN      0x08
  30
  31/* General Purpose Power Management */
  32#define VX855_PMIO_GPPM         0x20
  33#define VX855_PMIO_R_GPI        0x48
  34#define VX855_PMIO_R_GPO        0x4c
  35#define VX855_PMIO_GPPM_LEN     0x33
  36
  37#define VSPIC_MMIO_SIZE 0x1000
  38
  39static struct resource vx855_gpio_resources[] = {
  40        {
  41                .flags = IORESOURCE_IO,
  42        },
  43        {
  44                .flags = IORESOURCE_IO,
  45        },
  46};
  47
  48static const struct mfd_cell vx855_cells[] = {
  49        {
  50                .name = "vx855_gpio",
  51                .num_resources = ARRAY_SIZE(vx855_gpio_resources),
  52                .resources = vx855_gpio_resources,
  53
  54                /* we must ignore resource conflicts, for reasons outlined in
  55                 * the vx855_gpio driver */
  56                .ignore_resource_conflicts = true,
  57        },
  58};
  59
  60static int vx855_probe(struct pci_dev *pdev,
  61                                 const struct pci_device_id *id)
  62{
  63        int ret;
  64        u16 gpio_io_offset;
  65
  66        ret = pci_enable_device(pdev);
  67        if (ret)
  68                return -ENODEV;
  69
  70        pci_read_config_word(pdev, VX855_CFG_PMIO_OFFSET, &gpio_io_offset);
  71        if (!gpio_io_offset) {
  72                dev_warn(&pdev->dev,
  73                        "BIOS did not assign PMIO base offset?!?\n");
  74                ret = -ENODEV;
  75                goto out;
  76        }
  77
  78        /* mask out the lowest seven bits, as they are always zero, but
  79         * hardware returns them as 0x01 */
  80        gpio_io_offset &= 0xff80;
  81
  82        /* As the region identified here includes many non-GPIO things, we
  83         * only work with the specific registers that concern us. */
  84        vx855_gpio_resources[0].start = gpio_io_offset + VX855_PMIO_R_GPI;
  85        vx855_gpio_resources[0].end = vx855_gpio_resources[0].start + 3;
  86        vx855_gpio_resources[1].start = gpio_io_offset + VX855_PMIO_R_GPO;
  87        vx855_gpio_resources[1].end = vx855_gpio_resources[1].start + 3;
  88
  89        ret = mfd_add_devices(&pdev->dev, -1, vx855_cells, ARRAY_SIZE(vx855_cells),
  90                        NULL, 0, NULL);
  91
  92        /* we always return -ENODEV here in order to enable other
  93         * drivers like old, not-yet-platform_device ported i2c-viapro */
  94        return -ENODEV;
  95out:
  96        pci_disable_device(pdev);
  97        return ret;
  98}
  99
 100static void vx855_remove(struct pci_dev *pdev)
 101{
 102        mfd_remove_devices(&pdev->dev);
 103        pci_disable_device(pdev);
 104}
 105
 106static const struct pci_device_id vx855_pci_tbl[] = {
 107        { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX855) },
 108        { 0, }
 109};
 110MODULE_DEVICE_TABLE(pci, vx855_pci_tbl);
 111
 112static struct pci_driver vx855_pci_driver = {
 113        .name           = "vx855",
 114        .id_table       = vx855_pci_tbl,
 115        .probe          = vx855_probe,
 116        .remove         = vx855_remove,
 117};
 118
 119module_pci_driver(vx855_pci_driver);
 120
 121MODULE_LICENSE("GPL");
 122MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>");
 123MODULE_DESCRIPTION("Driver for the VIA VX855 chipset");
 124