linux/drivers/acpi/acpi_cmos_rtc.c
Zhang Rui 596ca52a56 ACPI: TAD: Install SystemCMOS address space handler for ACPI000E
Currently, the SystemCMOS address space handler is installed for the
ACPI RTC devices (PNP0B00/PNP0B01/PNP0B02) only. But there are platforms
with SystemCMOS Operetion Region defined under the ACPI Time and Alarm
Device (ACPI000E), which is used by the ACPI pre-defined control methods
like _GRT (Get the Real time) and _SRT (Set the Real time).

When accessing these control methods via the acpi_tad sysfs interface,
missing SystemCMOS address space handler causes errors like below
[  478.255453] ACPI Error: No handler for Region [RTCM] (00000000a8d2dd39) [SystemCMOS] (20230331/evregion-130)
[  478.255458] ACPI Error: Region SystemCMOS (ID=5) has no handler (20230331/exfldio-261)
[  478.255461] Initialized Local Variables for Method [_GRT]:
[  478.255461]   Local1: 00000000f182542c <Obj>           Integer 0000000000000000
[  478.255464] No Arguments are initialized for method [_GRT]
[  478.255465] ACPI Error: Aborting method \_SB.AWAC._GRT due to previous error (AE_NOT_EXIST) (20230331/psparse-529)

Export two APIs for SystemCMOS address space handler from acpi_cmos_rtc
scan handler and install the handler for the ACPI Time and Alarm Device
from the ACPI TAD driver.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=217714
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
[ rjw: Subject and changelog edits, whitespace adjustment ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-08-17 20:01:24 +02:00

99 lines
2.3 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* ACPI support for CMOS RTC Address Space access
*
* Copyright (C) 2013, Intel Corporation
* Authors: Lan Tianyu <tianyu.lan@intel.com>
*/
#define pr_fmt(fmt) "ACPI: " fmt
#include <linux/acpi.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mc146818rtc.h>
#include "internal.h"
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;
}
int acpi_install_cmos_rtc_space_handler(acpi_handle handle)
{
acpi_status status;
status = acpi_install_address_space_handler(handle,
ACPI_ADR_SPACE_CMOS,
&acpi_cmos_rtc_space_handler,
NULL, NULL);
if (ACPI_FAILURE(status)) {
pr_err("Error installing CMOS-RTC region handler\n");
return -ENODEV;
}
return 1;
}
EXPORT_SYMBOL_GPL(acpi_install_cmos_rtc_space_handler);
void acpi_remove_cmos_rtc_space_handler(acpi_handle handle)
{
if (ACPI_FAILURE(acpi_remove_address_space_handler(handle,
ACPI_ADR_SPACE_CMOS, &acpi_cmos_rtc_space_handler)))
pr_err("Error removing CMOS-RTC region handler\n");
}
EXPORT_SYMBOL_GPL(acpi_remove_cmos_rtc_space_handler);
static int acpi_cmos_rtc_attach_handler(struct acpi_device *adev, const struct acpi_device_id *id)
{
return acpi_install_cmos_rtc_space_handler(adev->handle);
}
static void acpi_cmos_rtc_detach_handler(struct acpi_device *adev)
{
acpi_remove_cmos_rtc_space_handler(adev->handle);
}
static struct acpi_scan_handler cmos_rtc_handler = {
.ids = acpi_cmos_rtc_ids,
.attach = acpi_cmos_rtc_attach_handler,
.detach = acpi_cmos_rtc_detach_handler,
};
void __init acpi_cmos_rtc_init(void)
{
acpi_scan_add_handler(&cmos_rtc_handler);
}