On Tue, 22 Sep 2015, Andy Shevchenko wrote: > 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. This will require an ACPI Ack. > 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. -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html