[PATCH v3] ACPI: scan: Create platform device for CS35L56

[Richard Fitzgerald <rf@opensource.cirrus.com>]

From: Simon Trimmer <simont@opensource.cirrus.com>

The ACPI device CSC3556 is a Cirrus Logic CS35L56 mono amplifier which
is used in multiples, and can be connected either to I2C or SPI.

There will be multiple instances under the same Device() node. Add it
to ignore_serial_bus_ids and handle it in the serial-multi-instantiate
driver.

There can be a 5th I2cSerialBusV2, but this is an alias address and doesn't
represent a real device. Ignore this by having a dummy 5th entry in the
serial-multi-instantiate instance list with the name of a non-existent
driver, on the same pattern as done for bsg2150.

Signed-off-by: Simon Trimmer <simont@opensource.cirrus.com>
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
---
 drivers/acpi/scan.c                             |  1 +
 drivers/platform/x86/serial-multi-instantiate.c | 14 ++++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 5b145f1aaa1b..87e385542576 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1714,6 +1714,7 @@ static bool acpi_device_enumeration_by_parent(struct acpi_device *device)
 		{"BSG1160", },
 		{"BSG2150", },
 		{"CSC3551", },
+		{"CSC3556", },
 		{"INT33FE", },
 		{"INT3515", },
 		/* Non-conforming _HID for Cirrus Logic already released */
diff --git a/drivers/platform/x86/serial-multi-instantiate.c b/drivers/platform/x86/serial-multi-instantiate.c
index 2c2abf69f049..8158e3cf5d6d 100644
--- a/drivers/platform/x86/serial-multi-instantiate.c
+++ b/drivers/platform/x86/serial-multi-instantiate.c
@@ -329,6 +329,19 @@ static const struct smi_node cs35l41_hda = {
 	.bus_type = SMI_AUTO_DETECT,
 };
 
+static const struct smi_node cs35l56_hda = {
+	.instances = {
+		{ "cs35l56-hda", IRQ_RESOURCE_AUTO, 0 },
+		{ "cs35l56-hda", IRQ_RESOURCE_AUTO, 0 },
+		{ "cs35l56-hda", IRQ_RESOURCE_AUTO, 0 },
+		{ "cs35l56-hda", IRQ_RESOURCE_AUTO, 0 },
+		/* a 5th entry is an alias address, not a real device */
+		{ "cs35l56-hda_dummy_dev" },
+		{}
+	},
+	.bus_type = SMI_AUTO_DETECT,
+};
+
 /*
  * Note new device-ids must also be added to ignore_serial_bus_ids in
  * drivers/acpi/scan.c: acpi_device_enumeration_by_parent().
@@ -337,6 +350,7 @@ static const struct acpi_device_id smi_acpi_ids[] = {
 	{ "BSG1160", (unsigned long)&bsg1160_data },
 	{ "BSG2150", (unsigned long)&bsg2150_data },
 	{ "CSC3551", (unsigned long)&cs35l41_hda },
+	{ "CSC3556", (unsigned long)&cs35l56_hda },
 	{ "INT3515", (unsigned long)&int3515_data },
 	/* Non-conforming _HID for Cirrus Logic already released */
 	{ "CLSA0100", (unsigned long)&cs35l41_hda },
-- 
2.30.2