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Commit 62a615e0 authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Wolfram Sang
Browse files

mfd: core: redo ACPI matching of the children devices 



There is at least one board on the market, i.e. Intel Galileo Gen2, that uses
_ADR to distinguish the devices under one actual device. Due to this we have to
improve the quirk in the MFD core to handle that board.

Acked-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: default avatarLee Jones <lee.jones@linaro.org>
Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent 6a62974b

Documentation/acpi/enumeration.txt

+8 −3
Original line number Diff line number Diff line
@@ -347,13 +347,18 @@ For the first case, the MFD drivers do not need to do anything. The 
resulting child platform device will have its ACPI_COMPANION() set to point

to the parent device.



If the ACPI namespace has a device that we can match using an ACPI id,

the id should be set like:

If the ACPI namespace has a device that we can match using an ACPI id or ACPI

adr, the cell should be set like:



	static struct mfd_cell_acpi_match my_subdevice_cell_acpi_match = {

		.pnpid = "XYZ0001",

		.adr = 0,

	};



	static struct mfd_cell my_subdevice_cell = {

		.name = "my_subdevice",

		/* set the resources relative to the parent */

		.acpi_pnpid = "XYZ0001",

		.acpi_match = &my_subdevice_cell_acpi_match,

	};



The ACPI id "XYZ0001" is then used to lookup an ACPI device directly under

drivers/mfd/mfd-core.c

+36 −16
Original line number Diff line number Diff line
@@ -82,30 +82,50 @@ static int mfd_platform_add_cell(struct platform_device *pdev, 
static void mfd_acpi_add_device(const struct mfd_cell *cell,

				struct platform_device *pdev)

{

	struct acpi_device *parent_adev;

	const struct mfd_cell_acpi_match *match = cell->acpi_match;

	struct acpi_device *parent, *child;

	struct acpi_device *adev;



	parent_adev = ACPI_COMPANION(pdev->dev.parent);

	if (!parent_adev)

	parent = ACPI_COMPANION(pdev->dev.parent);

	if (!parent)

		return;



	/*

	 * MFD child device gets its ACPI handle either from the ACPI

	 * device directly under the parent that matches the acpi_pnpid or

	 * it will use the parent handle if is no acpi_pnpid is given.

	 * MFD child device gets its ACPI handle either from the ACPI device

	 * directly under the parent that matches the either _HID or _CID, or

	 * _ADR or it will use the parent handle if is no ID is given.

	 *

	 * Note that use of _ADR is a grey area in the ACPI specification,

	 * though Intel Galileo Gen2 is using it to distinguish the children

	 * devices.

	 */

	adev = parent_adev;

	if (cell->acpi_pnpid) {

	adev = parent;

	if (match) {

		if (match->pnpid) {

			struct acpi_device_id ids[2] = {};

		struct acpi_device *child_adev;



		strlcpy(ids[0].id, cell->acpi_pnpid, sizeof(ids[0].id));

		list_for_each_entry(child_adev, &parent_adev->children, node)

			if (acpi_match_device_ids(child_adev, ids)) {

				adev = child_adev;

			strlcpy(ids[0].id, match->pnpid, sizeof(ids[0].id));

			list_for_each_entry(child, &parent->children, node) {

				if (acpi_match_device_ids(child, ids)) {

					adev = child;

					break;

				}

			}

		} else {

			unsigned long long adr;

			acpi_status status;



			list_for_each_entry(child, &parent->children, node) {

				status = acpi_evaluate_integer(child->handle,

							       "_ADR", NULL,

							       &adr);

				if (ACPI_SUCCESS(status) && match->adr == adr) {

					adev = child;

					break;

				}

			}

		}

	}



	ACPI_COMPANION_SET(&pdev->dev, adev);

}

include/linux/mfd/core.h

+8 −2
Original line number Diff line number Diff line
@@ -18,6 +18,12 @@ 


struct irq_domain;



/* Matches ACPI PNP id, either _HID or _CID, or ACPI _ADR */

struct mfd_cell_acpi_match {

	const char			*pnpid;

	const unsigned long long	adr;

};



/*

 * This struct describes the MFD part ("cell").

 * After registration the copy of this structure will become the platform data
@@ -44,8 +50,8 @@ struct mfd_cell { 
	 */

	const char		*of_compatible;



	/* Matches ACPI PNP id, either _HID or _CID */

	const char		*acpi_pnpid;

	/* Matches ACPI */

	const struct mfd_cell_acpi_match	*acpi_match;



	/*

	 * These resources can be specified relative to the parent device.