diff options
Diffstat (limited to 'drivers/acpi/acpi_lpss.c')
| -rw-r--r-- | drivers/acpi/acpi_lpss.c | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c index 7f2b02cc8ea1..2bcffec8dbf0 100644 --- a/drivers/acpi/acpi_lpss.c +++ b/drivers/acpi/acpi_lpss.c @@ -427,6 +427,142 @@ out: return 0; } +struct lpss_device_links { + const char *supplier_hid; + const char *supplier_uid; + const char *consumer_hid; + const char *consumer_uid; + u32 flags; +}; + +/* + * The _DEP method is used to identify dependencies but instead of creating + * device links for every handle in _DEP, only links in the following list are + * created. That is necessary because, in the general case, _DEP can refer to + * devices that might not have drivers, or that are on different buses, or where + * the supplier is not enumerated until after the consumer is probed. + */ +static const struct lpss_device_links lpss_device_links[] = { + {"808622C1", "7", "80860F14", "3", DL_FLAG_PM_RUNTIME}, +}; + +static bool hid_uid_match(const char *hid1, const char *uid1, + const char *hid2, const char *uid2) +{ + return !strcmp(hid1, hid2) && uid1 && uid2 && !strcmp(uid1, uid2); +} + +static bool acpi_lpss_is_supplier(struct acpi_device *adev, + const struct lpss_device_links *link) +{ + return hid_uid_match(acpi_device_hid(adev), acpi_device_uid(adev), + link->supplier_hid, link->supplier_uid); +} + +static bool acpi_lpss_is_consumer(struct acpi_device *adev, + const struct lpss_device_links *link) +{ + return hid_uid_match(acpi_device_hid(adev), acpi_device_uid(adev), + link->consumer_hid, link->consumer_uid); +} + +struct hid_uid { + const char *hid; + const char *uid; +}; + +static int match_hid_uid(struct device *dev, void *data) +{ + struct acpi_device *adev = ACPI_COMPANION(dev); + struct hid_uid *id = data; + + if (!adev) + return 0; + + return hid_uid_match(acpi_device_hid(adev), acpi_device_uid(adev), + id->hid, id->uid); +} + +static struct device *acpi_lpss_find_device(const char *hid, const char *uid) +{ + struct hid_uid data = { + .hid = hid, + .uid = uid, + }; + + return bus_find_device(&platform_bus_type, NULL, &data, match_hid_uid); +} + +static bool acpi_lpss_dep(struct acpi_device *adev, acpi_handle handle) +{ + struct acpi_handle_list dep_devices; + acpi_status status; + int i; + + if (!acpi_has_method(adev->handle, "_DEP")) + return false; + + status = acpi_evaluate_reference(adev->handle, "_DEP", NULL, + &dep_devices); + if (ACPI_FAILURE(status)) { + dev_dbg(&adev->dev, "Failed to evaluate _DEP.\n"); + return false; + } + + for (i = 0; i < dep_devices.count; i++) { + if (dep_devices.handles[i] == handle) + return true; + } + + return false; +} + +static void acpi_lpss_link_consumer(struct device *dev1, + const struct lpss_device_links *link) +{ + struct device *dev2; + + dev2 = acpi_lpss_find_device(link->consumer_hid, link->consumer_uid); + if (!dev2) + return; + + if (acpi_lpss_dep(ACPI_COMPANION(dev2), ACPI_HANDLE(dev1))) + device_link_add(dev2, dev1, link->flags); + + put_device(dev2); +} + +static void acpi_lpss_link_supplier(struct device *dev1, + const struct lpss_device_links *link) +{ + struct device *dev2; + + dev2 = acpi_lpss_find_device(link->supplier_hid, link->supplier_uid); + if (!dev2) + return; + + if (acpi_lpss_dep(ACPI_COMPANION(dev1), ACPI_HANDLE(dev2))) + device_link_add(dev1, dev2, link->flags); + + put_device(dev2); +} + +static void acpi_lpss_create_device_links(struct acpi_device *adev, + struct platform_device *pdev) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(lpss_device_links); i++) { + const struct lpss_device_links *link = &lpss_device_links[i]; + + if (acpi_lpss_is_supplier(adev, link)) + acpi_lpss_link_consumer(&pdev->dev, link); + + if (acpi_lpss_is_consumer(adev, link)) + acpi_lpss_link_supplier(&pdev->dev, link); + } +} + static int acpi_lpss_create_device(struct acpi_device *adev, const struct acpi_device_id *id) { @@ -465,6 +601,8 @@ static int acpi_lpss_create_device(struct acpi_device *adev, acpi_dev_free_resource_list(&resource_list); if (!pdata->mmio_base) { + /* Avoid acpi_bus_attach() instantiating a pdev for this dev. */ + adev->pnp.type.platform_id = 0; /* Skip the device, but continue the namespace scan. */ ret = 0; goto err_out; @@ -500,6 +638,7 @@ static int acpi_lpss_create_device(struct acpi_device *adev, adev->driver_data = pdata; pdev = acpi_create_platform_device(adev, dev_desc->properties); if (!IS_ERR_OR_NULL(pdev)) { + acpi_lpss_create_device_links(adev, pdev); return 1; } |