Some devices have multiple I2cSerialBus resources and for things to work
an i2c-client must be instantiated for each, each with its own
i2c_device_id.

Normally we only instantiate an i2c-client for the first resource, using
the ACPI HID as id.

This commit adds a list of HIDs of devices, which need multiple i2c-clients
instantiated from a single fwnode, to acpi_device_enumeration_by_parent and
makes acpi_device_enumeration_by_parent return false for these devices so
that a platform device will be instantiated.

This allows the drivers/platform/x86/i2c-multi-instantiate.c driver, which
knows which i2c_device_id to use for each resource, to bind to the fwnode
and initiate an i2c-client for each resource.

Signed-off-by: Hans de Goede <hdego...@redhat.com>
---
 drivers/acpi/scan.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 6799d00dd790..44068066d269 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1540,6 +1540,18 @@ static bool acpi_device_enumeration_by_parent(struct 
acpi_device *device)
 {
        struct list_head resource_list;
        bool is_serial_bus_slave = false;
+       /*
+        * These devices have multiple I2cSerialBus resources and an i2c-client
+        * must be instantiated for each, each with its own i2c_device_id.
+        * Normally we only instantiate an i2c-client for the first resource,
+        * using the ACPI HID as id. These special cases are handled by the
+        * drivers/platform/x86/i2c-multi-instantiate.c driver, which knows
+        * which i2c_device_id to use for each resource.
+        */
+       static const struct acpi_device_id i2c_multi_instantiate_ids[] = {
+               {"BSG1160", 0},
+               {"", 0},
+       };
 
        if (acpi_is_indirect_io_slave(device))
                return true;
@@ -1551,6 +1563,10 @@ static bool acpi_device_enumeration_by_parent(struct 
acpi_device *device)
             fwnode_property_present(&device->fwnode, "baud")))
                return true;
 
+       /* Instantiate a pdev for the i2c-multi-instantiate drv to bind to */
+       if (!acpi_match_device_ids(device, i2c_multi_instantiate_ids))
+               return false;
+
        INIT_LIST_HEAD(&resource_list);
        acpi_dev_get_resources(device, &resource_list,
                               acpi_check_serial_bus_slave,
-- 
2.18.0

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