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: 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>

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 13f4701..06c0a30 100644 (file)
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -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;

diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index d159cef..e5bbb9c 100644 (file)
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -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
 
 /*