linux/linux-5.18.11/drivers/eisa/pci_eisa.c

90 lines
2.3 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Minimalist driver for a generic PCI-to-EISA bridge.
*
* (C) 2003 Marc Zyngier <maz@wild-wind.fr.eu.org>
*
* Ivan Kokshaysky <ink@jurassic.park.msu.ru> :
* Generalisation from i82375 to PCI_CLASS_BRIDGE_EISA.
*/
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/eisa.h>
#include <linux/pci.h>
#include <linux/module.h>
#include <linux/init.h>
/* There is only *one* pci_eisa device per machine, right ? */
static struct eisa_root_device pci_eisa_root;
static int __init pci_eisa_init(struct pci_dev *pdev)
{
int rc, i;
struct resource *res, *bus_res = NULL;
if ((rc = pci_enable_device (pdev))) {
dev_err(&pdev->dev, "Could not enable device\n");
return rc;
}
/*
* The Intel 82375 PCI-EISA bridge is a subtractive-decode PCI
* device, so the resources available on EISA are the same as those
* available on the 82375 bus. This works the same as a PCI-PCI
* bridge in subtractive-decode mode (see pci_read_bridge_bases()).
* We assume other PCI-EISA bridges are similar.
*
* eisa_root_register() can only deal with a single io port resource,
* so we use the first valid io port resource.
*/
pci_bus_for_each_resource(pdev->bus, res, i)
if (res && (res->flags & IORESOURCE_IO)) {
bus_res = res;
break;
}
if (!bus_res) {
dev_err(&pdev->dev, "No resources available\n");
return -1;
}
pci_eisa_root.dev = &pdev->dev;
pci_eisa_root.res = bus_res;
pci_eisa_root.bus_base_addr = bus_res->start;
pci_eisa_root.slots = EISA_MAX_SLOTS;
pci_eisa_root.dma_mask = pdev->dma_mask;
dev_set_drvdata(pci_eisa_root.dev, &pci_eisa_root);
if (eisa_root_register (&pci_eisa_root)) {
dev_err(&pdev->dev, "Could not register EISA root\n");
return -1;
}
return 0;
}
/*
* We have to call pci_eisa_init_early() before pnpacpi_init()/isapnp_init().
* Otherwise pnp resource will get enabled early and could prevent eisa
* to be initialized.
* Also need to make sure pci_eisa_init_early() is called after
* x86/pci_subsys_init().
* So need to use subsys_initcall_sync with it.
*/
static int __init pci_eisa_init_early(void)
{
struct pci_dev *dev = NULL;
int ret;
for_each_pci_dev(dev)
if ((dev->class >> 8) == PCI_CLASS_BRIDGE_EISA) {
ret = pci_eisa_init(dev);
if (ret)
return ret;
}
return 0;
}
subsys_initcall_sync(pci_eisa_init_early);