This is to fix acpica returns an error and terminate when BIOS ASL
tries to access ACPI's RTC CMOS registers as the below example:
Device (RTC)
{
Name (_HID, EisaId ("PNP0B00"))
...
OperationRegion (CMS0, SystemCMOS, Zero, 0x40)
Field (CMS0, ByteAcc, NoLock, Preserve)
{
RTSE, 8,
Offset (0x02),
RTMN, 8,
Offset (0x04),
RTHR, 8,
Offset (0x06),
RTDY, 8,
RTDE, 8
}
}
Method (_Q33, 0, NotSerialized)
{
Store (^^RTC.RTMN, Local0)
FromBCD (Local0, Local0)
Store (^^RTC.RTHR, Local1)
FromBCD (Local1, Local1)
Store (^^RTC.RTDY, Local2)
Store (^^RTC.RTSE, Local3)
...
}
Signed-off-by: Alex Hung <alex.hung@xxxxxxxxxxxxx>
---
drivers/acpi/Kconfig | 9 +++
drivers/acpi/Makefile | 1 +
drivers/acpi/acpi_rtc.c | 149 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 159 insertions(+)
create mode 100644 drivers/acpi/acpi_rtc.c
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 38c5078..fb90397 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -181,6 +181,15 @@ config ACPI_DOCK
This driver supports ACPI-controlled docking stations and removable
drive bays such as the IBM Ultrabay and the Dell Module Bay.
+config ACPI_RTC
+ tristate "RTC"
+ default m
+ help
+ This driver supports an ACPI RTC device. It enables BIOS to read and
+ to write ACPI RTC registers declared in an OperationRegion with
+ RegionSpace as SYSTEMCMOS. This is required if BIOS needs to access
+ RTC registers during run-time such as a number of HP laptops.
+
config ACPI_I2C
def_tristate I2C
depends on I2C
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index 2a4502b..383c62b 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -71,6 +71,7 @@ obj-$(CONFIG_ACPI_EC_DEBUGFS) += ec_sys.o
obj-$(CONFIG_ACPI_CUSTOM_METHOD)+= custom_method.o
obj-$(CONFIG_ACPI_BGRT) += bgrt.o
obj-$(CONFIG_ACPI_I2C) += acpi_i2c.o
+obj-$(CONFIG_ACPI_RTC) += acpi_rtc.o
# processor has its own "processor." module_param namespace
processor-y := processor_driver.o processor_throttling.o
diff --git a/drivers/acpi/acpi_rtc.c b/drivers/acpi/acpi_rtc.c
new file mode 100644
index 0000000..8d6b76b
--- /dev/null
+++ b/drivers/acpi/acpi_rtc.c
@@ -0,0 +1,149 @@
+/*
+ * acpi_rtc - ACPI RTC Driver
+ *
+ * Copyright (C) 2013 Alex Hung <alex.hung@xxxxxxxxxxxxx>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/acpi.h>
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("acpi*:PNP0B00:*");
+MODULE_ALIAS("acpi*:PNP0B01:*");
+MODULE_ALIAS("acpi*:PNP0B02:*");
+
+static const struct acpi_device_id rtc_device_ids[] = {
+ {"PNP0B00", 0},
+ {"PNP0B01", 0},
+ {"PNP0B02", 0},
+ {"", 0},
+};
+
+static acpi_status acpi_acpi_handle_locate_callback(acpi_handle handle,
+ u32 level, void *context, void **return_value)
+{
+ struct acpi_device *dev = context;
+
+ dev->handle = handle;
+ *(acpi_handle *)return_value = handle;
+
+ return AE_CTRL_TERMINATE;
+}
+
+static acpi_status
+acpi_rtc_space_handler(u32 function, acpi_physical_address address,
+ u32 bits, u64 *value64,
+ void *handler_context, void *region_context)
+{
+ pr_warn("Accessing CMOS offset 0x%02llx is skipped.\n", address);
+
+ return AE_OK;
+}
+
+static int rtc_install_handlers(struct acpi_device *rtc_dev)
+{
+ acpi_status status;
+ status = acpi_install_address_space_handler(rtc_dev->handle,
+ ACPI_ADR_SPACE_CMOS,
+ &acpi_rtc_space_handler,
+ NULL, rtc_dev);
+ if (ACPI_FAILURE(status)) {
+ pr_info("Fail to install ACPI RTC handler\n");
+ return AE_ERROR;
+ }
+
+ return 0;
+}
+
+static int acpi_rtc_add(struct acpi_device *device)
+{
+ int ret;
+ int i;
+ acpi_status status;
+ acpi_handle rtc_dev = NULL;
+
+ for (i = 0; i < sizeof(rtc_device_ids) /
+ sizeof(struct acpi_device_id) - 1; i++) {
+ status = acpi_get_devices(rtc_device_ids[i].id,
+ acpi_acpi_handle_locate_callback,
+ &rtc_dev, &rtc_dev);
+ if (ACPI_SUCCESS(status) && rtc_dev)
+ break;
+ }
+
+ if (!ACPI_SUCCESS(status) || !rtc_dev)
+ return AE_NOT_FOUND;
+
+ ret = rtc_install_handlers((struct acpi_device *) &rtc_dev);
+
+ return ret;
+}
+
+static int acpi_rtc_remove(struct acpi_device *device, int type)
+{
+ acpi_status status;
+ status = acpi_remove_address_space_handler(device->handle,
+ ACPI_ADR_SPACE_CMOS,
+ &acpi_rtc_space_handler);
+ if (!ACPI_SUCCESS(status))
+ return AE_ERROR;
+
+ return AE_OK;
+}
+
+static struct acpi_driver acpi_rtc_driver = {
+ .name = "rtc",
+ .class = "ACPI_RTC_CLASS",
+ .ids = rtc_device_ids,
+ .ops = {
+ .add = acpi_rtc_add,
+ .remove = acpi_rtc_remove,
+ },
+};
+
+static int __init rtc_init(void)
+{
+ int err;
+
+ pr_info("Initializing ACPI RTC module\n");
+ err = acpi_bus_register_driver(&acpi_rtc_driver);
+ if (err) {
+ pr_err("Unable to register acpi driver.\n");
+ goto error_acpi_register;
+ }
+
+ return 0;
+
+error_acpi_register:
+
+ return err;
+}
+
+static void __exit rtc_exit(void)
+{
+ pr_info("Exiting ACPI RTC module\n");
+ acpi_bus_unregister_driver(&acpi_rtc_driver);
+}
+
+module_init(rtc_init);
+module_exit(rtc_exit);
