Unverified Commit 87e59b36 authored by Stefan Binding's avatar Stefan Binding Committed by Mark Brown
Browse files

spi: Support selection of the index of the ACPI Spi Resource before alloc 



If a node contains more than one SPI resource it may be necessary to
use an index to select which one you want to allocate a spi device for.

Signed-off-by: default avatarStefan Binding <sbinding@opensource.cirrus.com>
Reviewed-by: default avatarHans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220121172431.6876-4-sbinding@opensource.cirrus.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 000bee0e

drivers/spi/spi.c

+44 −7
Original line number Diff line number Diff line
@@ -2320,6 +2320,8 @@ struct acpi_spi_lookup { 
	int			irq;

	u8			bits_per_word;

	u8			chip_select;

	int			n;

	int			index;

};



static void acpi_spi_parse_apple_properties(struct acpi_device *dev,
@@ -2351,6 +2353,8 @@ static void acpi_spi_parse_apple_properties(struct acpi_device *dev, 
		lookup->mode |= SPI_CPHA;

}



static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev);



static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)

{

	struct acpi_spi_lookup *lookup = data;
@@ -2364,13 +2368,34 @@ static int acpi_spi_add_resource(struct acpi_resource *ares, void *data) 
		sb = &ares->data.spi_serial_bus;

		if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {



			if (lookup->index != -1 && lookup->n++ != lookup->index)

				return 1;



			if (lookup->index == -1 && !ctlr)

				return -ENODEV;



			status = acpi_get_handle(NULL,

						 sb->resource_source.string_ptr,

						 &parent_handle);



			if (ACPI_FAILURE(status) ||

			    ACPI_HANDLE(ctlr->dev.parent) != parent_handle)

			if (ACPI_FAILURE(status))

				return -ENODEV;



			if (ctlr) {

				if (ACPI_HANDLE(ctlr->dev.parent) != parent_handle)

					return -ENODEV;

			} else {

				struct acpi_device *adev;



				if (acpi_bus_get_device(parent_handle, &adev))

					return -ENODEV;



				ctlr = acpi_spi_find_controller_by_adev(adev);

				if (!ctlr)

					return -ENODEV;



				lookup->ctlr = ctlr;

			}



			/*

			 * ACPI DeviceSelection numbering is handled by the
@@ -2414,14 +2439,21 @@ static int acpi_spi_add_resource(struct acpi_resource *ares, void *data) 
 * acpi_spi_device_alloc - Allocate a spi device, and fill it in with ACPI information

 * @ctlr: controller to which the spi device belongs

 * @adev: ACPI Device for the spi device

 * @index: Index of the spi resource inside the ACPI Node

 *

 * This should be used to allocate a new spi device from and ACPI Node.

 * The caller is responsible for calling spi_add_device to register the spi device.

 *

 * If ctlr is set to NULL, the Controller for the spi device will be looked up

 * using the resource.

 * If index is set to -1, index is not used.

 * Note: If index is -1, ctlr must be set.

 *

 * Return: a pointer to the new device, or ERR_PTR on error.

 */

struct spi_device *acpi_spi_device_alloc(struct spi_controller *ctlr,

					 struct acpi_device *adev)

					 struct acpi_device *adev,

					 int index)

{

	acpi_handle parent_handle = NULL;

	struct list_head resource_list;
@@ -2429,8 +2461,13 @@ struct spi_device *acpi_spi_device_alloc(struct spi_controller *ctlr, 
	struct spi_device *spi;

	int ret;



	if (!ctlr && index == -1)

		return ERR_PTR(-EINVAL);



	lookup.ctlr		= ctlr;

	lookup.irq		= -1;

	lookup.index		= index;

	lookup.n		= 0;



	INIT_LIST_HEAD(&resource_list);

	ret = acpi_dev_get_resources(adev, &resource_list,
@@ -2443,7 +2480,7 @@ struct spi_device *acpi_spi_device_alloc(struct spi_controller *ctlr, 


	if (!lookup.max_speed_hz &&

	    ACPI_SUCCESS(acpi_get_parent(adev->handle, &parent_handle)) &&

	    ACPI_HANDLE(ctlr->dev.parent) == parent_handle) {

	    ACPI_HANDLE(lookup.ctlr->dev.parent) == parent_handle) {

		/* Apple does not use _CRS but nested devices for SPI slaves */

		acpi_spi_parse_apple_properties(adev, &lookup);

	}
@@ -2451,9 +2488,9 @@ struct spi_device *acpi_spi_device_alloc(struct spi_controller *ctlr, 
	if (!lookup.max_speed_hz)

		return ERR_PTR(-ENODEV);



	spi = spi_alloc_device(ctlr);

	spi = spi_alloc_device(lookup.ctlr);

	if (!spi) {

		dev_err(&ctlr->dev, "failed to allocate SPI device for %s\n",

		dev_err(&lookup.ctlr->dev, "failed to allocate SPI device for %s\n",

			dev_name(&adev->dev));

		return ERR_PTR(-ENOMEM);

	}
@@ -2478,7 +2515,7 @@ static acpi_status acpi_register_spi_device(struct spi_controller *ctlr, 
	    acpi_device_enumerated(adev))

		return AE_OK;



	spi = acpi_spi_device_alloc(ctlr, adev);

	spi = acpi_spi_device_alloc(ctlr, adev, -1);

	if (IS_ERR(spi)) {

		if (PTR_ERR(spi) == -ENOMEM)

			return AE_NO_MEMORY;

include/linux/spi/spi.h

+2 −1
Original line number Diff line number Diff line
@@ -762,7 +762,8 @@ extern void spi_unregister_controller(struct spi_controller *ctlr); 


#if IS_ENABLED(CONFIG_ACPI)

extern struct spi_device *acpi_spi_device_alloc(struct spi_controller *ctlr,

						struct acpi_device *adev);

						struct acpi_device *adev,

						int index);

#endif



/*