[PATCH 03/14] ALSA: hda: intel-dsp-config: add helper for ACPI DSP driver selection

[Pierre-Louis Bossart]

Mirror capabilities provided for PCI devices, so that distributions
can select which ACPI driver is loaded at run-time with kernel
parameters and DMI tables instead of forcing a build-time selection.

The "legacy" option supported for HDaudio has no meaning here and will
be ignored.

The 'SST' driver based on closed-source firmware has the priority to
avoid any impact on users, and the choice to use SOF is strictly
opt-in. This may change at some point when the 'SST' driver is
deprecated on Baytrail/Cherrytrail.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan at linux.intel.com>
Reviewed-by: Rander Wang <rander.wang at linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski at linux.intel.com>
---
 include/sound/intel-dsp-config.h |  7 +++
 sound/hda/intel-dsp-config.c     | 77 ++++++++++++++++++++++++++++++++
 2 files changed, 84 insertions(+)

diff --git a/include/sound/intel-dsp-config.h b/include/sound/intel-dsp-config.h
index c36622bee3f8..d4609077c258 100644
--- a/include/sound/intel-dsp-config.h
+++ b/include/sound/intel-dsp-config.h
@@ -21,6 +21,7 @@ enum {
 #if IS_ENABLED(CONFIG_SND_INTEL_DSP_CONFIG)
 
 int snd_intel_dsp_driver_probe(struct pci_dev *pci);
+int snd_intel_acpi_dsp_driver_probe(struct device *dev, const u8 acpi_hid[ACPI_ID_LEN]);
 
 #else
 
@@ -29,6 +30,12 @@ static inline int snd_intel_dsp_driver_probe(struct pci_dev *pci)
 	return SND_INTEL_DSP_DRIVER_ANY;
 }
 
+static inline
+int snd_intel_acpi_dsp_driver_probe(struct device *dev, const u8 acpi_hid[ACPI_ID_LEN])
+{
+	return SND_INTEL_DSP_DRIVER_ANY;
+}
+
 #endif
 
 #endif
diff --git a/sound/hda/intel-dsp-config.c b/sound/hda/intel-dsp-config.c
index 1c5114dedda9..7e6b8571c138 100644
--- a/sound/hda/intel-dsp-config.c
+++ b/sound/hda/intel-dsp-config.c
@@ -29,6 +29,7 @@ MODULE_PARM_DESC(dsp_driver, "Force the DSP driver for Intel DSP (0=auto, 1=lega
 struct config_entry {
 	u32 flags;
 	u16 device;
+	u8 acpi_hid[ACPI_ID_LEN];
 	const struct dmi_system_id *dmi_table;
 };
 
@@ -433,6 +434,82 @@ int snd_intel_dsp_driver_probe(struct pci_dev *pci)
 }
 EXPORT_SYMBOL_GPL(snd_intel_dsp_driver_probe);
 
+/*
+ * configuration table
+ * - the order of similar ACPI ID entries is important!
+ * - the first successful match will win
+ */
+static const struct config_entry acpi_config_table[] = {
+/* BayTrail */
+#if IS_ENABLED(CONFIG_SND_SST_ATOM_HIFI2_PLATFORM_ACPI)
+	{
+		.flags = FLAG_SST,
+		.acpi_hid = "80860F28",
+	},
+#endif
+#if IS_ENABLED(CONFIG_SND_SOC_SOF_BAYTRAIL)
+	{
+		.flags = FLAG_SOF,
+		.acpi_hid = "80860F28",
+	},
+#endif
+/* CherryTrail */
+#if IS_ENABLED(CONFIG_SND_SST_ATOM_HIFI2_PLATFORM_ACPI)
+	{
+		.flags = FLAG_SST,
+		.acpi_hid = "808622A8",
+	},
+#endif
+#if IS_ENABLED(CONFIG_SND_SOC_SOF_BAYTRAIL)
+	{
+		.flags = FLAG_SOF,
+		.acpi_hid = "808622A8",
+	},
+#endif
+};
+
+static const struct config_entry *snd_intel_acpi_dsp_find_config(const u8 acpi_hid[ACPI_ID_LEN],
+								 const struct config_entry *table,
+								 u32 len)
+{
+	for (; len > 0; len--, table++) {
+		if (memcmp(table->acpi_hid, acpi_hid, ACPI_ID_LEN))
+			continue;
+		if (table->dmi_table && !dmi_check_system(table->dmi_table))
+			continue;
+		return table;
+	}
+	return NULL;
+}
+
+int snd_intel_acpi_dsp_driver_probe(struct device *dev, const u8 acpi_hid[ACPI_ID_LEN])
+{
+	const struct config_entry *cfg;
+
+	if (dsp_driver > SND_INTEL_DSP_DRIVER_LEGACY && dsp_driver <= SND_INTEL_DSP_DRIVER_LAST)
+		return dsp_driver;
+
+	if (dsp_driver == SND_INTEL_DSP_DRIVER_LEGACY) {
+		dev_warn(dev, "dsp_driver parameter %d not supported, using automatic detection\n",
+			 SND_INTEL_DSP_DRIVER_LEGACY);
+	}
+
+	/* find the configuration for the specific device */
+	cfg = snd_intel_acpi_dsp_find_config(acpi_hid,  acpi_config_table,
+					     ARRAY_SIZE(acpi_config_table));
+	if (!cfg)
+		return SND_INTEL_DSP_DRIVER_ANY;
+
+	if (cfg->flags & FLAG_SST)
+		return SND_INTEL_DSP_DRIVER_SST;
+
+	if (cfg->flags & FLAG_SOF)
+		return SND_INTEL_DSP_DRIVER_SOF;
+
+	return SND_INTEL_DSP_DRIVER_SST;
+}
+EXPORT_SYMBOL_GPL(snd_intel_acpi_dsp_driver_probe);
+
 MODULE_LICENSE("GPL v2");
 MODULE_DESCRIPTION("Intel DSP config driver");
 MODULE_IMPORT_NS(SOUNDWIRE_INTEL_INIT);
-- 
2.25.1