[PATCH 19/41] ACPI: updates rtc-cmos device platform_data

Len Brown
2007-02-13T05:50:10Z

From: David Brownell <david-b@pacbell.net>

Update ACPI to export its RTC extension information through platform_data
to the PNPACPI or platform bus device node used on the system being set up.

This will need to be updated later to provide a firmware hook to handle
system suspend with an alarm pending.

Len notes that "Eventually we may bundle ACPI/PNP/PNPACPI..." but if/when
that happens, ACPI can simplify this without my help.

And until it does, the separate patch creating a platform_device (on all
X86_PC systems, even without ACPI) will be needed.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
---
drivers/acpi/glue.c | 89 +++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 89 insertions(+), 0 deletions(-)

diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
index 7b6c9ff..9950087 100644
--- a/drivers/acpi/glue.c
+++ b/drivers/acpi/glue.c
@@ -241,3 +241,92 @@ static int __init init_acpi_device_notify(void)
}

arch_initcall(init_acpi_device_notify);
+
+
+#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE)
+
+/* Every ACPI platform has a mc146818 compatible "cmos rtc". Here we find
+ * its device node and pass extra config data. This helps its driver use
+ * capabilities that the now-obsolete mc146818 didn't have, and informs it
+ * that this board's RTC is wakeup-capable (per ACPI spec).
+ */
+#include <linux/mc146818rtc.h>
+
+static struct cmos_rtc_board_info rtc_info;
+
+
+#ifdef CONFIG_PNPACPI
+
+/* PNP devices are registered in a subsys_initcall();
+ * ACPI specifies the PNP IDs to use.
+ */
+#include <linux/pnp.h>
+
+static int __init pnp_match(struct device *dev, void *data)
+{
+ static const char *ids[] = { "PNP0b00", "PNP0b01", "PNP0b02", };
+ struct pnp_dev *pnp = to_pnp_dev(dev);
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(ids); i++) {
+ if (compare_pnp_id(pnp->id, ids[i]) != 0)
+ return 1;
+ }
+ return 0;
+}
+
+static struct device *__init get_rtc_dev(void)
+{
+ return bus_find_device(&pnp_bus_type, NULL, NULL, pnp_match);
+}
+
+#else
+
+/* We expect non-PNPACPI platforms to register an RTC device, usually
+ * at or near arch_initcall(). That also helps for example PCs that
+ * aren't configured with ACPI (where this code wouldn't run, but the
+ * RTC would still be available). The device name matches the driver;
+ * that's how the platform bus works.
+ */
+#include <linux/platform_device.h>
+
+static int __init platform_match(struct device *dev, void *data)
+{
+ struct platform_device *pdev;
+
+ pdev = container_of(dev, struct platform_device, dev);
+ return strcmp(pdev->name, "rtc_cmos") == 0;
+}
+
+static struct device *__init get_rtc_dev(void)
+{
+ return bus_find_device(&platform_bus_type, NULL, NULL, platform_match);
+}
+
+#endif
+
+static int __init acpi_rtc_init(void)
+{
+ struct device *dev = get_rtc_dev();
+
+ if (dev) {
+ rtc_info.rtc_day_alarm = acpi_gbl_FADT.day_alarm;
+ rtc_info.rtc_mon_alarm = acpi_gbl_FADT.month_alarm;
+ rtc_info.rtc_century = acpi_gbl_FADT.century;
+
+ /* NOTE: acpi_gbl_FADT->rtcs4 is NOT currently useful */
+
+ dev->platform_data = &rtc_info;
+
+ /* RTC always wakes from S1/S2/S3, and often S4/STD */
+ device_init_wakeup(dev, 1);
+
+ put_device(dev);
+ } else
+ pr_debug("ACPI: RTC unavailable?\n");
+ return 0;
+}
+/* do this between RTC subsys_initcall() and rtc_cmos driver_initcall() */
+fs_initcall(acpi_rtc_init);
+
+#endif
--
1.5.0.rc4.345.gb4d2