[PATCH v3 2/4] ACPI / scan: Create platform device for fwnodes with multiple i2c devices

Hans de Goede
2018-08-07T08:05:37Z

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 <hdegoede@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