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.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
Documentation/acpi/enumeration.txt | 11 +++++---
drivers/mfd/mfd-core.c | 52 ++++++++++++++++++++++++++------------
include/linux/mfd/core.h | 10 ++++++--
3 files changed, 52 insertions(+), 21 deletions(-)
diff --git a/Documentation/acpi/enumeration.txt b/Documentation/acpi/enumeration.txt
index b731b29..a91ec5a 100644
--- a/Documentation/acpi/enumeration.txt
+++ b/Documentation/acpi/enumeration.txt
@@ -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
diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
index c17635d..60b60dc 100644
--- a/drivers/mfd/mfd-core.c
+++ b/drivers/mfd/mfd-core.c
@@ -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;
-
- 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;
+ adev = parent;
+ if (match) {
+ if (match->pnpid) {
+ struct acpi_device_id ids[2] = {};
+
+ 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);
diff --git a/include/linux/mfd/core.h b/include/linux/mfd/core.h
index a76bc10..27dac3f 100644
--- a/include/linux/mfd/core.h
+++ b/include/linux/mfd/core.h
@@ -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.
--
2.5.1
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