On Wednesday, January 16, 2013 11:15:25 AM Alex Hung wrote: > This is to fix acpica returns an error and terminate AML execution as > soon as BIOS tries to access ACPI's RTC registers. > > BugLink: http://launchpad.net/bugs/1065066 Can you please describe the problem in more detail in the changelog itself? Providing a link to the bug report doesn't explain why you think this fix is the best possible one. Which quite frankly I'm not sure of. > Signed-off-by: Alex Hung <alex.hung@xxxxxxxxxxxxx> > --- > drivers/acpi/Kconfig | 9 +++ > drivers/acpi/Makefile | 1 + > drivers/acpi/acpi_rtc.c | 140 +++++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 150 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..0ddcfc8 > --- /dev/null > +++ b/drivers/acpi/acpi_rtc.c > @@ -0,0 +1,140 @@ > +/* > + * 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/pci.h> > +#include <linux/acpi.h> > +#include <acpi/acpi_bus.h> > +#include <acpi/acpi_drivers.h> > +#include <linux/miscdevice.h> > + > +#define pr_fmt(fmt) "acpi_rtc: " fmt > + > +MODULE_LICENSE("GPL"); > +MODULE_ALIAS("acpi*:PNP0B00:*"); > + > +static const struct acpi_device_id rtc_device_ids[] = { > + {"PNP0B00", 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; > + > + 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) > +{ > + 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; > + acpi_status status; > + acpi_handle rtc_dev; > + > + status = acpi_get_devices(rtc_device_ids[0].id, > + acpi_acpi_handle_locate_callback, > + &rtc_dev, &rtc_dev); > + if (!ACPI_SUCCESS(status)) > + 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); So all it does is to install an empty address space handler for the CMOS address space, right? Bob, I wonder what you think about that? Rafael -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
