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Commit 2d12b6b3 authored by Lukas Wunner's avatar Lukas Wunner Committed by Rafael J. Wysocki
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ACPI / utils: Add acpi_dev_present() 



There's an idiom in use by 7 Linux drivers to detect the presence of a
particular ACPI HID by walking the namespace with acpi_get_devices().
The callback passed to acpi_get_devices() is mostly identical across
the drivers, leading to lots of duplicate code.

Add acpi_dev_present(), the ACPI equivalent to pci_dev_present(),
allowing us to deduplicate all that boilerplate in the drivers.

Signed-off-by: default avatarLukas Wunner <lukas@wunner.de>
Reviewed-by: default avatarHanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent ca9dc8d4

drivers/acpi/internal.h

+8 −0
Original line number Diff line number Diff line
@@ -86,6 +86,14 @@ bool acpi_scan_is_offline(struct acpi_device *adev, bool uevent); 
#define ACPI_STA_DEFAULT (ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED | \

			  ACPI_STA_DEVICE_UI | ACPI_STA_DEVICE_FUNCTIONING)



extern struct list_head acpi_bus_id_list;



struct acpi_device_bus_id{

	char bus_id[15];

	unsigned int instance_no;

	struct list_head node;

};



int acpi_device_add(struct acpi_device *device,

		    void (*release)(struct device *));

void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,

drivers/acpi/scan.c

+1 −7
Original line number Diff line number Diff line
@@ -39,7 +39,7 @@ static const char *dummy_hid = "device"; 


static LIST_HEAD(acpi_dep_list);

static DEFINE_MUTEX(acpi_dep_list_lock);

static LIST_HEAD(acpi_bus_id_list);

LIST_HEAD(acpi_bus_id_list);

static DEFINE_MUTEX(acpi_scan_lock);

static LIST_HEAD(acpi_scan_handlers_list);

DEFINE_MUTEX(acpi_device_lock);
@@ -52,12 +52,6 @@ struct acpi_dep_data { 
	acpi_handle slave;

};



struct acpi_device_bus_id{

	char bus_id[15];

	unsigned int instance_no;

	struct list_head node;

};



void acpi_scan_lock_acquire(void)

{

	mutex_lock(&acpi_scan_lock);

drivers/acpi/utils.c

+31 −0
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ 
#include <linux/dynamic_debug.h>



#include "internal.h"

#include "sleep.h"



#define _COMPONENT		ACPI_BUS_COMPONENT

ACPI_MODULE_NAME("utils");
@@ -709,6 +710,36 @@ bool acpi_check_dsm(acpi_handle handle, const u8 *uuid, int rev, u64 funcs) 
}

EXPORT_SYMBOL(acpi_check_dsm);



/**

 * acpi_dev_present - Detect presence of a given ACPI device in the system.

 * @hid: Hardware ID of the device.

 *

 * Return %true if the device was present at the moment of invocation.

 * Note that if the device is pluggable, it may since have disappeared.

 *

 * For this function to work, acpi_bus_scan() must have been executed

 * which happens in the subsys_initcall() subsection. Hence, do not

 * call from a subsys_initcall() or earlier (use acpi_get_devices()

 * instead). Calling from module_init() is fine (which is synonymous

 * with device_initcall()).

 */

bool acpi_dev_present(const char *hid)

{

	struct acpi_device_bus_id *acpi_device_bus_id;

	bool found = false;



	mutex_lock(&acpi_device_lock);

	list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)

		if (!strcmp(acpi_device_bus_id->bus_id, hid)) {

			found = true;

			break;

		}

	mutex_unlock(&acpi_device_lock);



	return found;

}

EXPORT_SYMBOL(acpi_dev_present);



/*

 * acpi_backlight= handling, this is done here rather then in video_detect.c

 * because __setup cannot be used in modules.

include/acpi/acpi_bus.h

+2 −0
Original line number Diff line number Diff line
@@ -87,6 +87,8 @@ acpi_evaluate_dsm_typed(acpi_handle handle, const u8 *uuid, int rev, int func, 
	  .package.elements = (eles)			\

	}



bool acpi_dev_present(const char *hid);



#ifdef CONFIG_ACPI



#include <linux/proc_fs.h>