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/*
* This file is part of the coreboot project.
*
* Copyright (C) 2015-2016 Intel Corp.
* (Written by Lance Zhao <lijian.zhao@intel.com> for Intel Corp.)
*
* 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.
*/
#include <device/device.h>
#include <device/pci.h>
#include <device/pci_ids.h>
#include <soc/acpi.h>
#include <soc/lpc.h>
#include <soc/pci_ids.h>
/*
* SCOPE:
* The purpose of this driver is to eliminate manual resource allocation for
* devices under the LPC bridge.
*
* BACKGROUND:
* The resource allocator reserves IO and memory resources to devices on the
* LPC bus, but it is up to the hardware driver to make sure that those
* resources are decoded to the LPC bus. This is what this driver does.
*
* THEORY OF OPERATION:
* The .scan_bus member of the driver's ops will scan the static device tree
* (devicetree.cb) and invoke drivers of devices on the LPC bus. This creates
* a list of child devices, along with their resources. set_child_resources()
* parses that list and looks for resources needed by the child devices. It
* opens up IO and memory windows as needed.
*/
static void soc_lpc_add_io_resources(device_t dev)
{
struct resource *res;
/* Add the default claimed legacy IO range for the LPC device. */
res = new_resource(dev, 0);
res->base = 0;
res->size = 0x1000;
res->flags = IORESOURCE_IO | IORESOURCE_ASSIGNED | IORESOURCE_FIXED;
}
static void soc_lpc_read_resources(device_t dev)
{
/* Get the PCI resources of this device. */
pci_dev_read_resources(dev);
/* Add IO resources to LPC. */
soc_lpc_add_io_resources(dev);
}
static void set_child_resources(struct device *dev);
static void loop_resources(struct device *dev)
{
struct resource *res;
for (res = dev->resource_list; res; res = res->next) {
if (res->flags & IORESOURCE_IO) {
lpc_open_pmio_window(res->base, res->size);
}
if (res->flags & IORESOURCE_MEM) {
/* Check if this is already decoded. */
if (lpc_fits_fixed_mmio_window(res->base, res->size))
continue;
lpc_open_mmio_window(res->base, res->size);
}
}
set_child_resources(dev);
}
/*
* Loop through all the child devices' resources, and open up windows to the
* LPC bus, as appropriate.
*/
static void set_child_resources(struct device *dev)
{
struct bus *link;
struct device *child;
for (link = dev->link_list; link; link = link->next) {
for (child = link->children; child; child = child->sibling) {
loop_resources(child);
}
}
}
static void set_resources(device_t dev)
{
pci_dev_set_resources(dev);
/* Close all previously opened windows and allocate from scratch. */
lpc_close_pmio_windows();
/* Now open up windows to devices which have declared resources. */
set_child_resources(dev);
}
static struct device_operations device_ops = {
.read_resources = &soc_lpc_read_resources,
.set_resources = set_resources,
.enable_resources = &pci_dev_enable_resources,
.write_acpi_tables = southbridge_write_acpi_tables,
.acpi_inject_dsdt_generator = southbridge_inject_dsdt,
.scan_bus = scan_lpc_bus,
};
static const struct pci_driver soc_lpc __pci_driver = {
.ops = &device_ops,
.vendor = PCI_VENDOR_ID_INTEL,
.device = PCI_DEVICE_ID_APOLLOLAKE_LPC,
};
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