Commit 733e6251 authored by Mika Westerberg's avatar Mika Westerberg Committed by Rafael J. Wysocki
Browse files

ACPI: Allow drivers to match using Device Tree compatible property 



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: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: default avatarGrant Likely <grant.likely@linaro.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent b31384fa

drivers/acpi/property.c

+39 −0
Original line number Diff line number Diff line
@@ -76,6 +76,42 @@ 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;

	int ret;



	/*

	 * 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;



	ret = acpi_dev_get_property_array(adev, "compatible", ACPI_TYPE_STRING,

					  &of_compatible);

	if (ret) {

		ret = acpi_dev_get_property(adev, "compatible",

					    ACPI_TYPE_STRING, &of_compatible);

		if (ret) {

			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 +155,8 @@ 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 +168,7 @@ 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;

}

drivers/acpi/scan.c

+95 −11
Original line number Diff line number Diff line
@@ -124,6 +124,44 @@ static int create_modalias(struct acpi_device *acpi_dev, char *modalias, 
	if (list_empty(&acpi_dev->pnp.ids))

		return 0;



	/*

	 * 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;

		int i, nval;

		char *c;



		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;

		if (of_compatible->type == ACPI_TYPE_PACKAGE) {

			nval = of_compatible->package.count;

			obj = of_compatible->package.elements;

		} else { /* Must be ACPI_TYPE_STRING. */

			nval = 1;

			obj = of_compatible;

		}

		for (i = 0; i < nval; i++, obj++) {

			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;
@@ -136,6 +174,7 @@ static int create_modalias(struct acpi_device *acpi_dev, char *modalias, 
			len += count;

			size -= count;

		}

	}



	modalias[len] = '\0';

	return len;
@@ -902,6 +941,51 @@ 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, *obj;

	struct acpi_device *adev;

	int i, nval;



	adev = ACPI_COMPANION(dev);

	if (!adev)

		return false;



	of_compatible = adev->data.of_compatible;

	if (!drv->of_match_table || !of_compatible)

		return false;



	if (of_compatible->type == ACPI_TYPE_PACKAGE) {

		nval = of_compatible->package.count;

		obj = of_compatible->package.elements;

	} else { /* Must be ACPI_TYPE_STRING. */

		nval = 1;

		obj = of_compatible;

	}

	/* Now we can look for the driver DT compatible strings */

	for (i = 0; i < nval; i++, obj++) {

		const struct of_device_id *id;



		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;

include/acpi/acpi_bus.h

+1 −0
Original line number Diff line number Diff line
@@ -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 */

include/linux/acpi.h

+2 −6
Original line number Diff line number Diff line
@@ -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);

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