From 6ab3430129e258ea31dd214adf1c760dfafde67a Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Tue, 16 Sep 2014 14:52:36 +0300 Subject: mfd: Add ACPI support 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 does not 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 Reviewed-by: Darren Hart Signed-off-by: Lee Jones --- drivers/mfd/mfd-core.c | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) (limited to 'drivers/mfd') diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c index 5d0fbe1e097a..f3338fe9d069 100644 --- a/drivers/mfd/mfd-core.c +++ b/drivers/mfd/mfd-core.c @@ -78,6 +78,44 @@ 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; + + 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. + */ + 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; + } + } + + 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, @@ -119,6 +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); -- cgit v1.2.3