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

Bjorn Helgaas
2010-12-08T21:36:22Z

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);
+}