Re: [PATCH 03/13] ACPI: Allow drivers to match using Device Tree compatible property

Grant Likely
2014-10-14T13:38:00Z

On Tue, 07 Oct 2014 02:13:29 +0200
, "Rafael J. Wysocki" <rjw@rjwysocki.net>
wrote:
> 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>

Looks okay to me.

Reviewed-by: Grant Likely <grant.likely@linaro.org>

> ---
> 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
>
>