[PATCH RFC v2 1/2] ASoC: amd: acp: Add ACP70 ACPI flag override for LG gram 16Z95U

[fixca <jaehoon1744@dankook.ac.kr>]

From: Jaehoon Kim  <jaehoon1744@dankook.ac.kr>

The LG gram 16 (16Z95U, AMD Ryzen AI 400 series, ACP rev 0x72) BIOS
sets "acp-audio-config-flag" to 0x10 (FLAG_AMD_LEGACY_ONLY_DMIC), but
the machine has no ACP PDM microphone. All audio endpoints are
SoundWire peripherals declared under the ACP SoundWire controller:

  link 0: RT713 (UAJ + SmartMic functions), _ADR 0x000030025D071301
  link 1: RT1320 (SmartAmp function),      _ADR 0x000131025D132001

With the flag honoured, snd_pci_ps bails out with -ENODEV, the legacy
snd_acp_pci driver binds instead and fails with:

  platform acp_asoc_acp70.0: warning: No matching ASoC machine driver found

so no sound card is created at all.

Add the machine to acp70_acpi_flag_override_table so that the
SoundWire path is used.

Tested on LG gram 16Z95U-GS59K (PCI SSID 1854:056c): with this change
snd_pci_ps binds and both peripherals enumerate
(sdw:0:0:025d:0713:01, sdw:0:1:025d:1320:01).

Signed-off-by: Jaehoon Kim <jaehoon1744@dankook.ac.kr>
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
v2: rebased onto broonie/sound for-next (v1 did not apply).
 sound/soc/amd/acp-config.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/sound/soc/amd/acp-config.c b/sound/soc/amd/acp-config.c
index 3d4c852..febf559 100644
--- a/sound/soc/amd/acp-config.c
+++ b/sound/soc/amd/acp-config.c
@@ -140,6 +140,13 @@ static const struct dmi_system_id acp70_acpi_flag_override_table[] = {
 			DMI_MATCH(DMI_PRODUCT_NAME, "Dell 14S DS14265"),
 		},
 	},
+	{
+		/* LG gram 16 16Z95U (ACP 7.2) */
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "LG Electronics"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "16Z95U"),
+		},
+	},
 	{}
 };
 
-- 
2.43.0