cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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vx855.c (3238B)

      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");