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path: root/drivers/eisa/pci_eisa.c
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Diffstat (limited to 'drivers/eisa/pci_eisa.c')
-rw-r--r--drivers/eisa/pci_eisa.c89
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 0000000000..8173e60bb8
--- /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)
+{
+ struct resource *res, *bus_res = NULL;
+ int rc;
+
+ 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)
+ 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);