| Message ID | 1408255459-17625-6-git-send-email-mika.westerberg@linux.intel.com (mailing list archive) |
|---|---|
| State | RFC, archived |
| Headers | show |
On Sun, 17 Aug 2014, Mika Westerberg wrote: > If an MFD device is backed by ACPI namespace, we should allow subdevice > drivers to access their corresponding ACPI companion devices through normal > means (e.g using ACPI_COMPANION()). > > This patch adds such support to the MFD core. If the MFD parent device > doesn't specify any ACPI _HID/_CID for the child device, the child device > will share the parent ACPI companion device. Otherwise the child device > will be assigned with the corresponding ACPI companion, if found in the > namespace below the parent. > > Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> > Reviewed-by: Darren Hart <dvhart@linux.intel.com> > --- > Documentation/acpi/enumeration.txt | 27 +++++++++++++++++++++++++ > drivers/mfd/mfd-core.c | 41 ++++++++++++++++++++++++++++++++++++++ > include/linux/mfd/core.h | 3 +++ > 3 files changed, 71 insertions(+) > > diff --git a/Documentation/acpi/enumeration.txt b/Documentation/acpi/enumeration.txt > index e182be5e3c83..74e35c54febf 100644 > --- a/Documentation/acpi/enumeration.txt > +++ b/Documentation/acpi/enumeration.txt > @@ -312,3 +312,30 @@ a code like this: > > There are also devm_* versions of these functions which release the > descriptors once the device is released. > + > +MFD devices > +~~~~~~~~~~~ > +The MFD devices create platform devices from their children. For the > +child devices there needs to be an ACPI handle that they can use to > +reference parts of the ACPI namespace that relate to them. In the Linux > +MFD subsystem we provide two ways: > + > + o The children share the parent ACPI handle. > + o The MFD cell can specify the ACPI id of the device. > + > +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: > + > + static struct mfd_cell my_subdevice_cell = { > + .name = "my_subdevice", > + /* set the resources relative to the parent */ > + .acpi_pnpid = "XYZ0001", > + }; > + > +The ACPI id "XYZ0001" is then used to lookup an ACPI device directly under > +the MFD device and if found, that ACPI companion device is bound to the > +resulting child platform device. > diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c > index 892d343193ad..bb466b28b3b6 100644 > --- a/drivers/mfd/mfd-core.c > +++ b/drivers/mfd/mfd-core.c > @@ -78,6 +78,45 @@ static int mfd_platform_add_cell(struct platform_device *pdev, > return 0; > } > > +#if IS_ENABLED(CONFIG_ACPI) > +static void mfd_acpi_add_device(const struct mfd_cell *cell, > + struct platform_device *pdev) > +{ > + struct acpi_device *parent_adev; > + struct acpi_device *adev = NULL; > + > + parent_adev = ACPI_COMPANION(pdev->dev.parent); > + if (!parent_adev) > + 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. > + */ > + 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; > + } What happens if cell->acpi_pnpid is provided, but not matched? Surely adev will them be NULL? In these cases shouldn't you then "adev = parent_adev"? > + } else { > + adev = parent_adev; > + } > + > + ACPI_COMPANION_SET(&pdev->dev, adev); > +} > +#else > +static inline void mfd_acpi_add_device(const struct mfd_cell *cell, > + struct platform_device *pdev) > +{ > +} > +#endif > + > static int mfd_add_device(struct device *parent, int id, > const struct mfd_cell *cell, atomic_t *usage_count, > struct resource *mem_base, > @@ -118,6 +157,8 @@ static int mfd_add_device(struct device *parent, int id, > } > } > > + mfd_acpi_add_device(cell, pdev); > + > if (cell->pdata_size) { > ret = platform_device_add_data(pdev, > cell->platform_data, cell->pdata_size); > diff --git a/include/linux/mfd/core.h b/include/linux/mfd/core.h > index f543de91ce19..73e1709d4c09 100644 > --- a/include/linux/mfd/core.h > +++ b/include/linux/mfd/core.h > @@ -44,6 +44,9 @@ struct mfd_cell { > */ > const char *of_compatible; > > + /* Matches ACPI PNP id, either _HID or _CID */ > + const char *acpi_pnpid; > + > /* > * These resources can be specified relative to the parent device. > * For accessing hardware you should use resources from the platform dev
On Thu, Aug 28, 2014 at 12:29:00PM +0100, Lee Jones wrote: > On Sun, 17 Aug 2014, Mika Westerberg wrote: > > > If an MFD device is backed by ACPI namespace, we should allow subdevice > > drivers to access their corresponding ACPI companion devices through normal > > means (e.g using ACPI_COMPANION()). > > > > This patch adds such support to the MFD core. If the MFD parent device > > doesn't specify any ACPI _HID/_CID for the child device, the child device > > will share the parent ACPI companion device. Otherwise the child device > > will be assigned with the corresponding ACPI companion, if found in the > > namespace below the parent. > > > > Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> > > Reviewed-by: Darren Hart <dvhart@linux.intel.com> > > --- > > Documentation/acpi/enumeration.txt | 27 +++++++++++++++++++++++++ > > drivers/mfd/mfd-core.c | 41 ++++++++++++++++++++++++++++++++++++++ > > include/linux/mfd/core.h | 3 +++ > > 3 files changed, 71 insertions(+) > > > > diff --git a/Documentation/acpi/enumeration.txt b/Documentation/acpi/enumeration.txt > > index e182be5e3c83..74e35c54febf 100644 > > --- a/Documentation/acpi/enumeration.txt > > +++ b/Documentation/acpi/enumeration.txt > > @@ -312,3 +312,30 @@ a code like this: > > > > There are also devm_* versions of these functions which release the > > descriptors once the device is released. > > + > > +MFD devices > > +~~~~~~~~~~~ > > +The MFD devices create platform devices from their children. For the > > +child devices there needs to be an ACPI handle that they can use to > > +reference parts of the ACPI namespace that relate to them. In the Linux > > +MFD subsystem we provide two ways: > > + > > + o The children share the parent ACPI handle. > > + o The MFD cell can specify the ACPI id of the device. > > + > > +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: > > + > > + static struct mfd_cell my_subdevice_cell = { > > + .name = "my_subdevice", > > + /* set the resources relative to the parent */ > > + .acpi_pnpid = "XYZ0001", > > + }; > > + > > +The ACPI id "XYZ0001" is then used to lookup an ACPI device directly under > > +the MFD device and if found, that ACPI companion device is bound to the > > +resulting child platform device. > > diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c > > index 892d343193ad..bb466b28b3b6 100644 > > --- a/drivers/mfd/mfd-core.c > > +++ b/drivers/mfd/mfd-core.c > > @@ -78,6 +78,45 @@ static int mfd_platform_add_cell(struct platform_device *pdev, > > return 0; > > } > > > > +#if IS_ENABLED(CONFIG_ACPI) > > +static void mfd_acpi_add_device(const struct mfd_cell *cell, > > + struct platform_device *pdev) > > +{ > > + struct acpi_device *parent_adev; > > + struct acpi_device *adev = NULL; > > + > > + parent_adev = ACPI_COMPANION(pdev->dev.parent); > > + if (!parent_adev) > > + 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. > > + */ > > + 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; > > + } > > What happens if cell->acpi_pnpid is provided, but not matched? > > Surely adev will them be NULL? > > In these cases shouldn't you then "adev = parent_adev"? Good point. I'll fix that in the next version. > > > + } else { > > + adev = parent_adev; > > + } > > + > > + ACPI_COMPANION_SET(&pdev->dev, adev); > > +} > > +#else > > +static inline void mfd_acpi_add_device(const struct mfd_cell *cell, > > + struct platform_device *pdev) > > +{ > > +} > > +#endif -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Documentation/acpi/enumeration.txt b/Documentation/acpi/enumeration.txt index e182be5e3c83..74e35c54febf 100644 --- a/Documentation/acpi/enumeration.txt +++ b/Documentation/acpi/enumeration.txt @@ -312,3 +312,30 @@ a code like this: There are also devm_* versions of these functions which release the descriptors once the device is released. + +MFD devices +~~~~~~~~~~~ +The MFD devices create platform devices from their children. For the +child devices there needs to be an ACPI handle that they can use to +reference parts of the ACPI namespace that relate to them. In the Linux +MFD subsystem we provide two ways: + + o The children share the parent ACPI handle. + o The MFD cell can specify the ACPI id of the device. + +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: + + static struct mfd_cell my_subdevice_cell = { + .name = "my_subdevice", + /* set the resources relative to the parent */ + .acpi_pnpid = "XYZ0001", + }; + +The ACPI id "XYZ0001" is then used to lookup an ACPI device directly under +the MFD device and if found, that ACPI companion device is bound to the +resulting child platform device. diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c index 892d343193ad..bb466b28b3b6 100644 --- a/drivers/mfd/mfd-core.c +++ b/drivers/mfd/mfd-core.c @@ -78,6 +78,45 @@ static int mfd_platform_add_cell(struct platform_device *pdev, return 0; } +#if IS_ENABLED(CONFIG_ACPI) +static void mfd_acpi_add_device(const struct mfd_cell *cell, + struct platform_device *pdev) +{ + struct acpi_device *parent_adev; + struct acpi_device *adev = NULL; + + parent_adev = ACPI_COMPANION(pdev->dev.parent); + if (!parent_adev) + 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. + */ + 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; + } + } else { + adev = parent_adev; + } + + ACPI_COMPANION_SET(&pdev->dev, adev); +} +#else +static inline void mfd_acpi_add_device(const struct mfd_cell *cell, + struct platform_device *pdev) +{ +} +#endif + static int mfd_add_device(struct device *parent, int id, const struct mfd_cell *cell, atomic_t *usage_count, struct resource *mem_base, @@ -118,6 +157,8 @@ static int mfd_add_device(struct device *parent, int id, } } + mfd_acpi_add_device(cell, pdev); + if (cell->pdata_size) { ret = platform_device_add_data(pdev, cell->platform_data, cell->pdata_size); diff --git a/include/linux/mfd/core.h b/include/linux/mfd/core.h index f543de91ce19..73e1709d4c09 100644 --- a/include/linux/mfd/core.h +++ b/include/linux/mfd/core.h @@ -44,6 +44,9 @@ struct mfd_cell { */ const char *of_compatible; + /* Matches ACPI PNP id, either _HID or _CID */ + const char *acpi_pnpid; + /* * These resources can be specified relative to the parent device. * For accessing hardware you should use resources from the platform dev