Commit e6ce0ce3 authored by Adrian Hunter's avatar Adrian Hunter Committed by Rafael J. Wysocki
Browse files

ACPI / LPSS: Add device link for CHT SD card dependency on I2C

Some Cherry Trail boards have a dependency between the SDHCI host
controller used for SD cards and an external PMIC accessed via I2C. Add a
device link between the SDHCI host controller (consumer) and the I2C
adapter (supplier).

This patch depends on a fix to devices links, namely commit 0ff26c66
("driver core: Fix device link deferred probe"). And also either,
commit 126dbc6b

 ("PM: i2c-designware-platdrv: Clean up PM handling in
probe"), or patch "PM / runtime: Fix handling of suppliers with disabled
runtime PM".

Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 50c4c4e2
......@@ -427,6 +427,142 @@ static int register_device_clock(struct acpi_device *adev,
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)
{
......@@ -500,6 +636,7 @@ 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;
}
......
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