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Commit 2fa97feb authored by Lan Tianyu's avatar Lan Tianyu Committed by Rafael J. Wysocki
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ACPI: Add CMOS RTC Operation Region handler support 

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.

References: https://bugzilla.kernel.org/show_bug.cgi?id=54621


Reported-and-tested-by: default avatarStefan Nagy <public@stefan-nagy.at>
Signed-off-by: default avatarLan Tianyu <tianyu.lan@intel.com>
Cc: 3.9+ <stable@vger.kernel.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 358b4b35

drivers/acpi/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -43,6 +43,7 @@ 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

drivers/acpi/acpi_cmos_rtc.c

0 → 100644
+92 −0
Original line number Diff line number Diff line 
/*

 * ACPI support for CMOS RTC Address Space access

 *

 * Copyright (C) 2013, Intel Corporation

 * Authors: Lan Tianyu <tianyu.lan@intel.com>

 *

 * 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);

}

drivers/acpi/internal.h

+5 −0
Original line number Diff line number Diff line
@@ -45,6 +45,11 @@ void acpi_memory_hotplug_init(void); 
#else

static inline void acpi_memory_hotplug_init(void) {}

#endif

#ifdef CONFIG_X86

void acpi_cmos_rtc_init(void);

#else

static inline void acpi_cmos_rtc_init(void) {}

#endif



void acpi_sysfs_add_hotplug_profile(struct acpi_hotplug_profile *hotplug,

				    const char *name);

drivers/acpi/scan.c

+1 −0
Original line number Diff line number Diff line
@@ -2040,6 +2040,7 @@ int __init acpi_scan_init(void) 
	acpi_pci_link_init();

	acpi_platform_init();

	acpi_lpss_init();

	acpi_cmos_rtc_init();

	acpi_container_init();

	acpi_memory_hotplug_init();