On HP Folio 13-2000, the BIOS defines a CMOS RTC Operation Region and the EC's _REG methord accesses that region. Thus an appropriate address space handler must be registered for that region before the EC driver is loaded. Introduce a mechanism for adding CMOS RTC address space handlers. Register an ACPI scan handler for CMOS RTC devices such that, when a device of that kind is detected during an ACPI namespace scan, a common CMOS RTC operation region address space handler will be installed for it. [rjw: Changelog] References: https://bugzilla.kernel.org/show_bug.cgi?id=54621 Reported-and-tested-by: Stefan Nagy <public@xxxxxxxxxxxxxx> Signed-off-by: Lan Tianyu <tianyu.lan@xxxxxxxxx> Cc: 3.9+ <stable@xxxxxxxxxxxxxxx> --- Change since v1: Make CMOS RTC operation region handler X86 specific and remove little endian conversion. drivers/acpi/Makefile | 1 + drivers/acpi/acpi_cmos_rtc.c | 92 ++++++++++++++++++++++++++++++++++++++++++ drivers/acpi/internal.h | 7 ++++ drivers/acpi/scan.c | 1 + 4 files changed, 101 insertions(+) create mode 100644 drivers/acpi/acpi_cmos_rtc.c diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile index d07771b..81dbeb8 100644 --- a/drivers/acpi/Makefile +++ b/drivers/acpi/Makefile @@ -44,6 +44,7 @@ acpi-y += acpi_platform.o acpi-y += power.o acpi-y += event.o acpi-y += sysfs.o +acpi-$(CONFIG_X86) += acpi_cmos_rtc.o acpi-$(CONFIG_DEBUG_FS) += debugfs.o acpi-$(CONFIG_ACPI_NUMA) += numa.o acpi-$(CONFIG_ACPI_PROCFS_POWER) += cm_sbs.o diff --git a/drivers/acpi/acpi_cmos_rtc.c b/drivers/acpi/acpi_cmos_rtc.c new file mode 100644 index 0000000..84190ed --- /dev/null +++ b/drivers/acpi/acpi_cmos_rtc.c @@ -0,0 +1,92 @@ +/* + * ACPI support for CMOS RTC Address Space access + * + * Copyright (C) 2013, Intel Corporation + * Authors: Lan Tianyu <tianyu.lan@xxxxxxxxx> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/acpi.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <asm-generic/rtc.h> + +#include "internal.h" + +#define PREFIX "ACPI: " + +ACPI_MODULE_NAME("cmos rtc"); + +static const struct acpi_device_id acpi_cmos_rtc_ids[] = { + { "PNP0B00" }, + { "PNP0B01" }, + { "PNP0B02" }, + {} +}; + +static acpi_status +acpi_cmos_rtc_space_handler(u32 function, acpi_physical_address address, + u32 bits, u64 *value64, + void *handler_context, void *region_context) +{ + int i; + u8 *value = (u8 *)&value64; + + if (address > 0xff || !value64) + return AE_BAD_PARAMETER; + + if (function != ACPI_WRITE && function != ACPI_READ) + return AE_BAD_PARAMETER; + + spin_lock_irq(&rtc_lock); + + for (i = 0; i < DIV_ROUND_UP(bits, 8); ++i, ++address, ++value) + if (function == ACPI_READ) + *value = CMOS_READ(address); + else + CMOS_WRITE(*value, address); + + spin_unlock_irq(&rtc_lock); + + return AE_OK; +} + +static int acpi_install_cmos_rtc_space_handler(struct acpi_device *adev, + const struct acpi_device_id *id) +{ + acpi_status status; + + status = acpi_install_address_space_handler(adev->handle, + ACPI_ADR_SPACE_CMOS, + &acpi_cmos_rtc_space_handler, + NULL, NULL); + if (ACPI_FAILURE(status)) { + pr_err(PREFIX "Error installing CMOS-RTC region handler\n"); + return -ENODEV; + } + + return 0; +} + +static void acpi_remove_cmos_rtc_space_handler(struct acpi_device *adev) +{ + if (ACPI_FAILURE(acpi_remove_address_space_handler(adev->handle, + ACPI_ADR_SPACE_CMOS, &acpi_cmos_rtc_space_handler))) + pr_err(PREFIX "Error removing CMOS-RTC region handler\n"); +} + +static struct acpi_scan_handler cmos_rtc_handler = { + .ids = acpi_cmos_rtc_ids, + .attach = acpi_install_cmos_rtc_space_handler, + .detach = acpi_remove_cmos_rtc_space_handler, +}; + +void __init acpi_cmos_rtc_init(void) +{ + acpi_scan_add_handler(&cmos_rtc_handler); +} diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h index 18a9d22..c82785f 100644 --- a/drivers/acpi/internal.h +++ b/drivers/acpi/internal.h @@ -36,6 +36,13 @@ void acpi_pci_root_hp_init(void); void acpi_processor_init(void); void acpi_platform_init(void); int acpi_sysfs_init(void); + +#ifdef CONFIG_X86 +void acpi_cmos_rtc_init(void); +#else +static inline void acpi_cmos_rtc_init(void) {} +#endif + #ifdef CONFIG_ACPI_CONTAINER void acpi_container_init(void); #else diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index a67f614..642e045 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -2159,6 +2159,7 @@ int __init acpi_scan_init(void) acpi_processor_init(); acpi_platform_init(); acpi_lpss_init(); + acpi_cmos_rtc_init(); acpi_container_init(); acpi_memory_hotplug_init(); -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html