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    Subject[PATCH 03/13] ACPI: Allow drivers to match using Device Tree compatible property
    Date
    From: Mika Westerberg <mika.westerberg@linux.intel.com>

    We have lots of existing Device Tree enabled drivers and allocating
    separate _HID for each is not feasible. Instead we allocate special _HID
    "PRP0001" that means that the match should be done using Device Tree
    compatible property using driver's .of_match_table instead if the driver
    is missing .acpi_match_table.

    If there is a need to distinguish from where the device is enumerated
    (DT/ACPI) driver can check dev->of_node or ACPI_COMPATION(dev).

    Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
    Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
    ---
    drivers/acpi/property.c | 34 +++++++++++++++++
    drivers/acpi/scan.c | 97 +++++++++++++++++++++++++++++++++++++++++++------
    include/acpi/acpi_bus.h | 1 +
    include/linux/acpi.h | 8 +---
    4 files changed, 123 insertions(+), 17 deletions(-)

    diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
    index 680f7f1..ff53eb8 100644
    --- a/drivers/acpi/property.c
    +++ b/drivers/acpi/property.c
    @@ -76,6 +76,37 @@ static bool acpi_properties_format_valid(const union acpi_object *properties)
    return true;
    }

    +static void acpi_init_of_compatible(struct acpi_device *adev)
    +{
    + const union acpi_object *of_compatible;
    + struct acpi_hardware_id *hwid;
    + bool acpi_of = false;
    +
    + /*
    + * Check if the special PRP0001 ACPI ID is present and in that
    + * case we fill in Device Tree compatible properties for this
    + * device.
    + */
    + list_for_each_entry(hwid, &adev->pnp.ids, list) {
    + if (!strcmp(hwid->id, "PRP0001")) {
    + acpi_of = true;
    + break;
    + }
    + }
    +
    + if (!acpi_of)
    + return;
    +
    + if (acpi_dev_get_property_array(adev, "compatible", ACPI_TYPE_STRING,
    + &of_compatible)) {
    + acpi_handle_warn(adev->handle,
    + "PRP0001 requires compatible property\n");
    + return;
    + }
    +
    + adev->data.of_compatible = of_compatible;
    +}
    +
    void acpi_init_properties(struct acpi_device *adev)
    {
    struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
    @@ -119,6 +150,8 @@ void acpi_init_properties(struct acpi_device *adev)

    adev->data.pointer = buf.pointer;
    adev->data.properties = properties;
    +
    + acpi_init_of_compatible(adev);
    return;
    }

    @@ -130,6 +163,7 @@ void acpi_init_properties(struct acpi_device *adev)
    void acpi_free_properties(struct acpi_device *adev)
    {
    ACPI_FREE((void *)adev->data.pointer);
    + adev->data.of_compatible = NULL;
    adev->data.pointer = NULL;
    adev->data.properties = NULL;
    }
    diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
    index 1979ab3..bc999f1 100644
    --- a/drivers/acpi/scan.c
    +++ b/drivers/acpi/scan.c
    @@ -124,17 +124,51 @@ static int create_modalias(struct acpi_device *acpi_dev, char *modalias,
    if (list_empty(&acpi_dev->pnp.ids))
    return 0;

    - len = snprintf(modalias, size, "acpi:");
    - size -= len;
    -
    - list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
    - count = snprintf(&modalias[len], size, "%s:", id->id);
    - if (count < 0)
    - return -EINVAL;
    - if (count >= size)
    - return -ENOMEM;
    - len += count;
    - size -= count;
    + /*
    + * If the device has PRP0001 we expose DT compatible modalias
    + * instead in form of of:NnameTCcompatible.
    + */
    + if (acpi_dev->data.of_compatible) {
    + struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
    + const union acpi_object *of_compatible, *obj;
    + char *c;
    + int i;
    +
    + acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf);
    + /* DT strings are all in lower case */
    + for (c = buf.pointer; *c != '\0'; c++)
    + *c = tolower(*c);
    +
    + len = snprintf(modalias, size, "of:N%sT", (char *)buf.pointer);
    + ACPI_FREE(buf.pointer);
    +
    + of_compatible = acpi_dev->data.of_compatible;
    + for (i = 0; i < of_compatible->package.count; i++) {
    + obj = &of_compatible->package.elements[i];
    +
    + count = snprintf(&modalias[len], size, "C%s",
    + obj->string.pointer);
    + if (count < 0)
    + return -EINVAL;
    + if (count >= size)
    + return -ENOMEM;
    +
    + len += count;
    + size -= count;
    + }
    + } else {
    + len = snprintf(modalias, size, "acpi:");
    + size -= len;
    +
    + list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
    + count = snprintf(&modalias[len], size, "%s:", id->id);
    + if (count < 0)
    + return -EINVAL;
    + if (count >= size)
    + return -ENOMEM;
    + len += count;
    + size -= count;
    + }
    }

    modalias[len] = '\0';
    @@ -864,6 +898,47 @@ int acpi_match_device_ids(struct acpi_device *device,
    }
    EXPORT_SYMBOL(acpi_match_device_ids);

    +/* Performs match against special "PRP0001" shoehorn ACPI ID */
    +static bool acpi_of_driver_match_device(struct device *dev,
    + const struct device_driver *drv)
    +{
    + const union acpi_object *of_compatible;
    + struct acpi_device *adev;
    + int i;
    +
    + adev = ACPI_COMPANION(dev);
    + if (!adev)
    + return false;
    +
    + of_compatible = adev->data.of_compatible;
    + if (!drv->of_match_table || !of_compatible)
    + return false;
    +
    + /* Now we can look for the driver DT compatible strings */
    + for (i = 0; i < of_compatible->package.count; i++) {
    + const struct of_device_id *id;
    + const union acpi_object *obj;
    +
    + obj = &of_compatible->package.elements[i];
    +
    + for (id = drv->of_match_table; id->compatible[0]; id++)
    + if (!strcasecmp(obj->string.pointer, id->compatible))
    + return true;
    + }
    +
    + return false;
    +}
    +
    +bool acpi_driver_match_device(struct device *dev,
    + const struct device_driver *drv)
    +{
    + if (!drv->acpi_match_table)
    + return acpi_of_driver_match_device(dev, drv);
    +
    + return !!acpi_match_device(drv->acpi_match_table, dev);
    +}
    +EXPORT_SYMBOL_GPL(acpi_driver_match_device);
    +
    static void acpi_free_power_resources_lists(struct acpi_device *device)
    {
    int i;
    diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
    index f9734fa..98cd723 100644
    --- a/include/acpi/acpi_bus.h
    +++ b/include/acpi/acpi_bus.h
    @@ -341,6 +341,7 @@ struct acpi_device_physical_node {
    struct acpi_device_data {
    const union acpi_object *pointer;
    const union acpi_object *properties;
    + const union acpi_object *of_compatible;
    };

    /* Device */
    diff --git a/include/linux/acpi.h b/include/linux/acpi.h
    index 18c1bc3..11aa6b8 100644
    --- a/include/linux/acpi.h
    +++ b/include/linux/acpi.h
    @@ -424,12 +424,8 @@ extern int acpi_nvs_for_each_region(int (*func)(__u64, __u64, void *),
    const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
    const struct device *dev);

    -static inline bool acpi_driver_match_device(struct device *dev,
    - const struct device_driver *drv)
    -{
    - return !!acpi_match_device(drv->acpi_match_table, dev);
    -}
    -
    +extern bool acpi_driver_match_device(struct device *dev,
    + const struct device_driver *drv);
    int acpi_device_uevent_modalias(struct device *, struct kobj_uevent_env *);
    int acpi_device_modalias(struct device *, char *, int);

    --
    1.9.3



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