ARM: amba: Auto-generate AMBA driver module aliases during modpost

This patch adds the necessary support in file2alias.c to define
suitable aliases based on the amba_id table in AMBA driver modules.

This should be sufficient to allow such modules to be auto-loaded
via udev.  The AMBA bus driver's uevent hotplug code is also
modified to pass an approriate MODALIAS string in the event.

For simplicity, the AMBA ID is treated an an opaque 32-bit numeber.
Module alises use patterns as appropriate to describe the value-
mask pairs described in the driver's amba_id list.

The proposed alias format is (extended regex):

    ^amba:d(HEX){8}$

Where HEX is a single upper-case HEX digit or a pattern (? or []
expression) matching a single upper-case HEX digit, as expected by
udev.

"d" is short for "device", following existing alias naming
conventions for other device types.  This adds some flexibility for
unambiguously extending the alias format in the future by adding
additional leading and trailing fields, if this turns out to be
necessary.

Signed-off-by: Dave Martin <dave.martin@linaro.org>
Acked-by: Pawel Moll <pawel.moll@arm.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
index bd230e801131..936c98cb2475 100644
--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -52,6 +52,10 @@ static int amba_uevent(struct device *dev, struct kobj_uevent_env *env)
 	int retval = 0;
 
 	retval = add_uevent_var(env, "AMBA_ID=%08x", pcdev->periphid);
+	if (retval)
+		return retval;
+
+	retval = add_uevent_var(env, "MODALIAS=amba:d%08X", pcdev->periphid);
 	return retval;
 }
 #else