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

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

Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220121172431.6876-3-sbinding@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Stefan Binding 2022-01-21 17:24:24 +00:00 committed by Mark Brown
parent e3dc139950
commit 000bee0ed7
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GPG Key ID: 24D68B725D5487D0
2 changed files with 42 additions and 10 deletions
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46
drivers/spi/spi.c
View File

@ -2410,8 +2410,18 @@ 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,
struct acpi_device *adev)
/**
* 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;
struct list_head resource_list;
@ -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));

6
include/linux/spi/spi.h
View File

@ -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
*/