[linux-2.6-block.git] / drivers / acpi / acpi_cmos_rtc.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);
}
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
2fa97feb LT	2	/*
	3	* ACPI support for CMOS RTC Address Space access
	4	*
	5	* Copyright (C) 2013, Intel Corporation
	6	* Authors: Lan Tianyu <tianyu.lan@intel.com>
2fa97feb LT	7	*/
2fa97feb LT	8
606e56c6 HG	9	#define pr_fmt(fmt) "ACPI: " fmt
606e56c6 HG	10
2fa97feb LT	11	#include <linux/acpi.h>
	12	#include <linux/device.h>
	13	#include <linux/err.h>
	14	#include <linux/kernel.h>
	15	#include <linux/module.h>
463a8630	16	#include <linux/mc146818rtc.h>
2fa97feb LT	17
	18	#include "internal.h"
	19
2fa97feb LT	20	static const struct acpi_device_id acpi_cmos_rtc_ids[] = {
	21	{ "PNP0B00" },
	22	{ "PNP0B01" },
	23	{ "PNP0B02" },
	24	{}
	25	};
	26
	27	static acpi_status
	28	acpi_cmos_rtc_space_handler(u32 function, acpi_physical_address address,
	29	u32 bits, u64 *value64,
	30	void handler_context, void region_context)
	31	{
	32	int i;
9389f46e	33	u8 value = (u8 )value64;
2fa97feb LT	34
	35	if (address > 0xff \|\| !value64)
	36	return AE_BAD_PARAMETER;
	37
	38	if (function != ACPI_WRITE && function != ACPI_READ)
	39	return AE_BAD_PARAMETER;
	40
	41	spin_lock_irq(&rtc_lock);
	42
	43	for (i = 0; i < DIV_ROUND_UP(bits, 8); ++i, ++address, ++value)
	44	if (function == ACPI_READ)
	45	*value = CMOS_READ(address);
	46	else
	47	CMOS_WRITE(*value, address);
	48
	49	spin_unlock_irq(&rtc_lock);
	50
	51	return AE_OK;
	52	}
	53
596ca52a	54	int acpi_install_cmos_rtc_space_handler(acpi_handle handle)
2fa97feb LT	55	{
	56	acpi_status status;
	57
596ca52a	58	status = acpi_install_address_space_handler(handle,
2fa97feb LT	59	ACPI_ADR_SPACE_CMOS,
	60	&acpi_cmos_rtc_space_handler,
	61	NULL, NULL);
	62	if (ACPI_FAILURE(status)) {
606e56c6	63	pr_err("Error installing CMOS-RTC region handler\n");
2fa97feb LT	64	return -ENODEV;
	65	}
	66
eec15edb	67	return 1;
2fa97feb	68	}
596ca52a	69	EXPORT_SYMBOL_GPL(acpi_install_cmos_rtc_space_handler);
2fa97feb	70
596ca52a	71	void acpi_remove_cmos_rtc_space_handler(acpi_handle handle)
2fa97feb	72	{
596ca52a	73	if (ACPI_FAILURE(acpi_remove_address_space_handler(handle,
2fa97feb	74	ACPI_ADR_SPACE_CMOS, &acpi_cmos_rtc_space_handler)))
606e56c6	75	pr_err("Error removing CMOS-RTC region handler\n");
2fa97feb	76	}
596ca52a ZR	77	EXPORT_SYMBOL_GPL(acpi_remove_cmos_rtc_space_handler);
	78
	79	static int acpi_cmos_rtc_attach_handler(struct acpi_device adev, const struct acpi_device_id id)
	80	{
	81	return acpi_install_cmos_rtc_space_handler(adev->handle);
	82	}
	83
	84	static void acpi_cmos_rtc_detach_handler(struct acpi_device *adev)
	85	{
	86	acpi_remove_cmos_rtc_space_handler(adev->handle);
	87	}
2fa97feb LT	88
	89	static struct acpi_scan_handler cmos_rtc_handler = {
	90	.ids = acpi_cmos_rtc_ids,
596ca52a ZR	91	.attach = acpi_cmos_rtc_attach_handler,
596ca52a ZR	92	.detach = acpi_cmos_rtc_detach_handler,
2fa97feb LT	93	};
	94
	95	void __init acpi_cmos_rtc_init(void)
	96	{
	97	acpi_scan_add_handler(&cmos_rtc_handler);
	98	}