Commit 758a7f7b authored Oct 14, 2008 by Bjorn Helgaas Committed by Linus Torvalds Oct 14, 2008

x86: register a platform RTC device if PNP doesn't describe it

Most if not all x86 platforms have an RTC device, but sometimes the RTC
is not exposed as a PNP0b00/PNP0b01/PNP0b02 device in PNPBIOS or ACPI:

    http://bugzilla.kernel.org/show_bug.cgi?id=11580
    https://bugzilla.redhat.com/show_bug.cgi?id=451188



It's best if we can discover the RTC via PNP because then we know
which flavor of device it is, where it lives, and which IRQ it uses.

But if we can't, we should register a platform device using the
compiled-in RTC_PORT/RTC_IRQ resource assumptions.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Reported-by: Rik Theys <rik.theys@esat.kuleuven.be>
Reported-by:  <shr_msn@yahoo.com.tw>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent a474aaed

arch/x86/kernel/rtc.c

+18 −4

Original line number	Diff line number	Diff line
		@@ -223,11 +223,25 @@ static struct platform_device rtc_device = {
		static __init int add_rtc_cmos(void)
		{
		#ifdef CONFIG_PNP
		if (!pnp_platform_devices)
		platform_device_register(&rtc_device);
		#else
		static const char *ids[] __initconst =
		{ "PNP0b00", "PNP0b01", "PNP0b02", };
		struct pnp_dev *dev;
		struct pnp_id *id;
		int i;

		pnp_for_each_dev(dev) {
		for (id = dev->id; id; id = id->next) {
		for (i = 0; i < ARRAY_SIZE(ids); i++) {
		if (compare_pnp_id(id, ids[i]) != 0)
		return 0;
		}
		}
		}
		#endif

		platform_device_register(&rtc_device);
		#endif /* CONFIG_PNP */
		dev_info(&rtc_device.dev,
		"registered platform RTC device (no PNP device found)\n");
		return 0;
		}
		device_initcall(add_rtc_cmos);

Admin message