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

Browse source 
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: Stefan Binding <sbinding@opensource.cirrus.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220121172431.6876-4-sbinding@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Stefan Binding 2022-01-21 17:24:25 +00:00 committed by Mark Brown
parent 000bee0ed7
commit 87e59b36e5
No known key found for this signature in database
GPG key ID: 24D68B725D5487D0
2 changed files with 46 additions and 8 deletions
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51
drivers/spi/spi.c
View file

@ -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;
@ -2364,14 +2368,35 @@ 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
* host controller driver in Windows and can vary
@ -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;

3
include/linux/spi/spi.h
View file

@ -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
/*