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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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Andy Shevchenko 2015-10-23 12:16:41 +03:00 committed by Wolfram Sang
parent 6a62974b66
commit 62a615e083
3 changed files with 51 additions and 20 deletions
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11
Documentation/acpi/enumeration.txt
View File

@ -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

50
drivers/mfd/mfd-core.c
View File

@ -82,29 +82,49 @@ 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) {
struct acpi_device_id ids[2] = {};
struct acpi_device *child_adev;
adev = parent;
if (match) {
if (match->pnpid) {
struct acpi_device_id ids[2] = {};
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;
break;
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);

10
include/linux/mfd/core.h
View File

@ -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.