// SPDX-License-Identifier: GPL-2.0-or-later

  /*
   * 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 <HaraldWelte@viatech.com>
   * All rights reserved.

   */
  
  #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 const 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 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?!?
  ");
  		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 vx855_remove(struct pci_dev *pdev)

  {
  	mfd_remove_devices(&pdev->dev);
  	pci_disable_device(pdev);
  }

  static const struct pci_device_id 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		= vx855_remove,

  };

  module_pci_driver(vx855_pci_driver);

  
  MODULE_LICENSE("GPL");
  MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>");
  MODULE_DESCRIPTION("Driver for the VIA VX855 chipset");