[PATCH] PCI: create revision file in sysfs

[Emil Velikov <emil.l.velikov@gmail.com>]

From: Emil Velikov <emil.velikov@collabora.com>

Currently the revision isn't available via sysfs/libudev thus if one
wants to know the value they need to read through the config file.

This in itself wakes/powers up the device, causing unwanted delay
since it can be quite costly.

Expose the revision as a separate file, just like we do for the device,
vendor, their subsystem version and class.

Cc: Jammy Zhou <Jammy.Zhou@amd.com>
Cc: Michel Dänzer <michel.daenzer@amd.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
---
Gents, I'm not subscribed to the mailing list so please keep me in the
CC chain.

Thanks
Emil
---
 drivers/pci/pci-sysfs.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index bcd10c7..0666287 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -50,6 +50,7 @@ pci_config_attr(vendor, "0x%04x\n");
 pci_config_attr(device, "0x%04x\n");
 pci_config_attr(subsystem_vendor, "0x%04x\n");
 pci_config_attr(subsystem_device, "0x%04x\n");
+pci_config_attr(revision, "0x%02x\n");
 pci_config_attr(class, "0x%06x\n");
 pci_config_attr(irq, "%u\n");
 
@@ -568,6 +569,7 @@ static struct attribute *pci_dev_attrs[] = {
 	&dev_attr_device.attr,
 	&dev_attr_subsystem_vendor.attr,
 	&dev_attr_subsystem_device.attr,
+	&dev_attr_revision.attr,
 	&dev_attr_class.attr,
 	&dev_attr_irq.attr,
 	&dev_attr_local_cpus.attr,
-- 
2.9.3