[PATCH 4/5] PNP: add framework for platform PNP quirks

[Bjorn Helgaas <bjorn.helgaas@hp.com>]

This allows platform quirks to fabricate PNP devices to describe things
that should have been described via ACPI.  For example, if the BIOS writer
forgets to describe a device, we may assign its address space to another
device, causing a conflict.  We can avoid the conflict by making a fake PNP
device to stand in for the one the BIOS missed.

In that case, there's no ACPI or PNPBIOS device, so we need a new
pnp_protocol that doesn't go back to firmware for get/set/wakeup/
suspend/etc.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
---

 drivers/pnp/base.h   |    2 ++
 drivers/pnp/core.c   |    9 ++++++++-
 drivers/pnp/quirks.c |   15 +++++++++++++++
 3 files changed, 25 insertions(+), 1 deletions(-)


diff --git a/drivers/pnp/base.h b/drivers/pnp/base.h
index 19bc736..dca301e 100644
--- a/drivers/pnp/base.h
+++ b/drivers/pnp/base.h
@@ -7,6 +7,8 @@ extern spinlock_t pnp_lock;
 extern struct device_attribute pnp_interface_attrs[];
 void *pnp_alloc(long size);
 
+void platform_pnp_fixups(void);
+
 int pnp_register_protocol(struct pnp_protocol *protocol);
 void pnp_unregister_protocol(struct pnp_protocol *protocol);
 
diff --git a/drivers/pnp/core.c b/drivers/pnp/core.c
index 0f34d96..5076493 100644
--- a/drivers/pnp/core.c
+++ b/drivers/pnp/core.c
@@ -212,7 +212,14 @@ void __pnp_remove_device(struct pnp_dev *dev)
 
 static int __init pnp_init(void)
 {
-	return bus_register(&pnp_bus_type);
+	int ret;
+
+	ret = bus_register(&pnp_bus_type);
+	if (ret)
+		return ret;
+
+	platform_pnp_fixups();
+	return 0;
 }
 
 subsys_initcall(pnp_init);
diff --git a/drivers/pnp/quirks.c b/drivers/pnp/quirks.c
index dfbd5a6..f18bb69 100644
--- a/drivers/pnp/quirks.c
+++ b/drivers/pnp/quirks.c
@@ -15,6 +15,7 @@
 
 #include <linux/types.h>
 #include <linux/kernel.h>
+#include <linux/dmi.h>
 #include <linux/string.h>
 #include <linux/slab.h>
 #include <linux/pnp.h>
@@ -337,3 +338,17 @@ void pnp_fixup_device(struct pnp_dev *dev)
 		f->quirk_function(dev);
 	}
 }
+
+static struct pnp_protocol pnp_fixup_protocol = {
+	.name = "Plug and Play fixup",
+};
+
+static const struct dmi_system_id pnp_fixup_table[] __initconst = {
+	{}
+};
+
+void __init platform_pnp_fixups(void)
+{
+	pnp_register_protocol(&pnp_fixup_protocol);
+	dmi_check_system(pnp_fixup_table);
+}