[PATCH 6.6.y] usb: typec: ucsi: acpi: Assume UCSI 1.2 on Acer Nitro ANV15-41

[Sasha Levin <sashal@kernel.org>]

From: Pannarat Wiriyaarritham <pannarat.wiriyaarritham@danielcorp.dev>

[ Upstream commit 8c51ea651d043c786c37668c51624bd6b338a0ef ]

The Acer Nitro ANV15-41 exposes a functional UCSI ACPI PPM but
reports a UCSI VERSION value of zero.

ucsi_register() rejects a zero version with -ENODEV, leaving the
system without registered USB Type-C connectors.

The PPM works correctly when using the UCSI 1.2 layout. With UCSI
1.2 assumed, both Type-C connectors register correctly and USB Power
Delivery negotiation works.

Add a DMI-specific UCSI operation for the Acer Nitro ANV15-41 that
substitutes UCSI 1.2 only when firmware reports a zero version.
Preserve any valid non-zero firmware version.

Tested on an Acer Nitro ANV15-41 with BIOS V1.51.

Fixes: c1b0bc2dabfa ("usb: typec: Add support for UCSI interface")
Cc: stable <stable@kernel.org>
Assisted-by: LLM
Signed-off-by: Pannarat Wiriyaarritham <pannarat.wiriyaarritham@danielcorp.dev>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://patch.msgid.link/20260910023338.31816-1-pannarat.wiriyaarritham@danielcorp.dev
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ sashal: Adapted .read_version to the generic .read callback with offset and length checks. ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/typec/ucsi/ucsi_acpi.c | 32 ++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/drivers/usb/typec/ucsi/ucsi_acpi.c b/drivers/usb/typec/ucsi/ucsi_acpi.c
index 1054947497bb2..7a4969a086df2 100644
--- a/drivers/usb/typec/ucsi/ucsi_acpi.c
+++ b/drivers/usb/typec/ucsi/ucsi_acpi.c
@@ -107,6 +107,31 @@ static const struct ucsi_operations ucsi_acpi_ops = {
 	.async_write = ucsi_acpi_async_write
 };
 
+static int ucsi_acer_read(struct ucsi *ucsi, unsigned int offset,
+			  void *val, size_t val_len)
+{
+	struct ucsi_acpi *ua = ucsi_get_drvdata(ucsi);
+	u16 *version = val;
+	int ret;
+
+	ret = ucsi_acpi_read(ucsi, offset, val, val_len);
+	if (ret)
+		return ret;
+
+	if (offset == UCSI_VERSION && val_len == sizeof(*version) && !*version) {
+		dev_warn(ua->dev, "UCSI version is zero, assuming 1.2\n");
+		*version = UCSI_VERSION_1_2;
+	}
+
+	return 0;
+}
+
+static const struct ucsi_operations ucsi_acer_ops = {
+	.read = ucsi_acer_read,
+	.sync_write = ucsi_acpi_sync_write,
+	.async_write = ucsi_acpi_async_write
+};
+
 static int
 ucsi_zenbook_read(struct ucsi *ucsi, unsigned int offset, void *val, size_t val_len)
 {
@@ -174,6 +199,13 @@ static const struct ucsi_operations ucsi_dell_ops = {
 };
 
 static const struct dmi_system_id ucsi_acpi_quirks[] = {
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Nitro ANV15-41"),
+		},
+		.driver_data = (void *)&ucsi_acer_ops,
+	},
 	{
 		.matches = {
 			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
-- 
2.53.0