Unverified Commit 000bee0e authored by Stefan Binding's avatar Stefan Binding Committed by Mark Brown
Browse files

spi: Create helper API to lookup ACPI info for spi device 



This can then be used to find a spi resource inside an
ACPI node, and allocate a spi device.

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/20220121172431.6876-3-sbinding@opensource.cirrus.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent e3dc1399

drivers/spi/spi.c

+36 −10
Original line number Diff line number Diff line
@@ -2410,7 +2410,17 @@ static int acpi_spi_add_resource(struct acpi_resource *ares, void *data) 
	return 1;

}



static acpi_status acpi_register_spi_device(struct spi_controller *ctlr,

/**

 * 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

 *

 * 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.

 *

 * 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)

{

	acpi_handle parent_handle = NULL;
@@ -2419,10 +2429,6 @@ static acpi_status acpi_register_spi_device(struct spi_controller *ctlr, 
	struct spi_device *spi;

	int ret;



	if (acpi_bus_get_status(adev) || !adev->status.present ||

	    acpi_device_enumerated(adev))

		return AE_OK;



	lookup.ctlr		= ctlr;

	lookup.irq		= -1;
@@ -2433,7 +2439,7 @@ static acpi_status acpi_register_spi_device(struct spi_controller *ctlr, 


	if (ret < 0)

		/* found SPI in _CRS but it points to another controller */

		return AE_OK;

		return ERR_PTR(-ENODEV);



	if (!lookup.max_speed_hz &&

	    ACPI_SUCCESS(acpi_get_parent(adev->handle, &parent_handle)) &&
@@ -2443,16 +2449,15 @@ static acpi_status acpi_register_spi_device(struct spi_controller *ctlr, 
	}



	if (!lookup.max_speed_hz)

		return AE_OK;

		return ERR_PTR(-ENODEV);



	spi = spi_alloc_device(ctlr);

	if (!spi) {

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

			dev_name(&adev->dev));

		return AE_NO_MEMORY;

		return ERR_PTR(-ENOMEM);

	}





	ACPI_COMPANION_SET(&spi->dev, adev);

	spi->max_speed_hz	= lookup.max_speed_hz;

	spi->mode		|= lookup.mode;
@@ -2460,6 +2465,27 @@ static acpi_status acpi_register_spi_device(struct spi_controller *ctlr, 
	spi->bits_per_word	= lookup.bits_per_word;

	spi->chip_select	= lookup.chip_select;



	return spi;

}

EXPORT_SYMBOL_GPL(acpi_spi_device_alloc);



static acpi_status acpi_register_spi_device(struct spi_controller *ctlr,

					    struct acpi_device *adev)

{

	struct spi_device *spi;



	if (acpi_bus_get_status(adev) || !adev->status.present ||

	    acpi_device_enumerated(adev))

		return AE_OK;



	spi = acpi_spi_device_alloc(ctlr, adev);

	if (IS_ERR(spi)) {

		if (PTR_ERR(spi) == -ENOMEM)

			return AE_NO_MEMORY;

		else

			return AE_OK;

	}



	acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias,

			  sizeof(spi->modalias));

include/linux/spi/spi.h

+6 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 
#include <linux/gpio/consumer.h>



#include <uapi/linux/spi/spi.h>

#include <linux/acpi.h>



struct dma_chan;

struct software_node;
@@ -759,6 +760,11 @@ extern int devm_spi_register_controller(struct device *dev, 
					struct spi_controller *ctlr);

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);

#endif



/*

 * SPI resource management while processing a SPI message

 */