1 files changed, 89 insertions, 0 deletions
diff --git a/drivers/eisa/pci_eisa.c b/drivers/eisa/pci_eisa.c
new file mode 100644
index 000000000..930c2332c
--- /dev/null
+++ b/drivers/eisa/pci_eisa.c
@@ -0,0 +1,89 @@
+// 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);