ALSA: hda: move Intel SoundWire ACPI scan to dedicated module

The ACPI scan capabilities is called from the intel-dspconfig as well
as the SOF/HDaudio drivers. This creates dependencies and randconfig issues
when HDaudio and SOF/SoundWire are not all configured as modules.

To simplify Kconfig dependencies between HDAudio, SoundWire, SOF and
intel-dspconfig, move the ACPI scan helpers to a dedicated
module. This follows the same idea as NHLT helpers which are already
handled as a dedicated module.

The only functional change is that the kernel parameter to filter
links is now handled by a different module, but that was only provided
for developers needing work-arounds for early BIOS releases.

Reported-by: Arnd Bergmann <[email protected]>
Signed-off-by: Pierre-Louis Bossart <[email protected]>
Reviewed-by: Kai Vehmanen <[email protected]>
Reviewed-by: Guennadi Liakhovetski <[email protected]>
Reviewed-by: Bard Liao <[email protected]>
Acked-by: Mark Brown <[email protected]>
Acked-by: Vinod Koul <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Takashi Iwai <[email protected]>

drivers/soundwire/intel.h

@@ -48,8 +48,6 @@ struct sdw_intel {
 #endif
 };
 
-#define SDW_INTEL_QUIRK_MASK_BUS_DISABLE      BIT(1)
-
 int intel_master_startup(struct platform_device *pdev);
 int intel_master_process_wakeen_event(struct platform_device *pdev);
 

drivers/soundwire/intel_init.c

@@ -18,42 +18,12 @@
 #include "cadence_master.h"
 #include "intel.h"
 
-#define SDW_LINK_TYPE		4 /* from Intel ACPI documentation */
-#define SDW_MAX_LINKS		4
 #define SDW_SHIM_LCAP		0x0
 #define SDW_SHIM_BASE		0x2C000
 #define SDW_ALH_BASE		0x2C800
 #define SDW_LINK_BASE		0x30000
 #define SDW_LINK_SIZE		0x10000
 
-static int ctrl_link_mask;
-module_param_named(sdw_link_mask, ctrl_link_mask, int, 0444);
-MODULE_PARM_DESC(sdw_link_mask, "Intel link mask (one bit per link)");
-
-static bool is_link_enabled(struct fwnode_handle *fw_node, int i)
-{
-	struct fwnode_handle *link;
-	char name[32];
-	u32 quirk_mask = 0;
-
-	/* Find master handle */
-	snprintf(name, sizeof(name),
-		 "mipi-sdw-link-%d-subproperties", i);
-
-	link = fwnode_get_named_child_node(fw_node, name);
-	if (!link)
-		return false;
-
-	fwnode_property_read_u32(link,
-				 "intel-quirk-mask",
-				 &quirk_mask);
-
-	if (quirk_mask & SDW_INTEL_QUIRK_MASK_BUS_DISABLE)
-		return false;
-
-	return true;
-}
-
 static int sdw_intel_cleanup(struct sdw_intel_ctx *ctx)
 {
 	struct sdw_intel_link_res *link = ctx->links;
@@ -81,74 +51,6 @@ static int sdw_intel_cleanup(struct sdw_intel_ctx *ctx)
 	return 0;
 }
 
-static int
-sdw_intel_scan_controller(struct sdw_intel_acpi_info *info)
-{
-	struct acpi_device *adev;
-	int ret, i;
-	u8 count;
-
-	if (acpi_bus_get_device(info->handle, &adev))
-		return -EINVAL;
-
-	/* Found controller, find links supported */
-	count = 0;
-	ret = fwnode_property_read_u8_array(acpi_fwnode_handle(adev),
-					    "mipi-sdw-master-count", &count, 1);
-
-	/*
-	 * In theory we could check the number of links supported in
-	 * hardware, but in that step we cannot assume SoundWire IP is
-	 * powered.
-	 *
-	 * In addition, if the BIOS doesn't even provide this
-	 * 'master-count' property then all the inits based on link
-	 * masks will fail as well.
-	 *
-	 * We will check the hardware capabilities in the startup() step
-	 */
-
-	if (ret) {
-		dev_err(&adev->dev,
-			"Failed to read mipi-sdw-master-count: %d\n", ret);
-		return -EINVAL;
-	}
-
-	/* Check count is within bounds */
-	if (count > SDW_MAX_LINKS) {
-		dev_err(&adev->dev, "Link count %d exceeds max %d\n",
-			count, SDW_MAX_LINKS);
-		return -EINVAL;
-	}
-
-	if (!count) {
-		dev_warn(&adev->dev, "No SoundWire links detected\n");
-		return -EINVAL;
-	}
-	dev_dbg(&adev->dev, "ACPI reports %d SDW Link devices\n", count);
-
-	info->count = count;
-	info->link_mask = 0;
-
-	for (i = 0; i < count; i++) {
-		if (ctrl_link_mask && !(ctrl_link_mask & BIT(i))) {
-			dev_dbg(&adev->dev,
-				"Link %d masked, will not be enabled\n", i);
-			continue;
-		}
-
-		if (!is_link_enabled(acpi_fwnode_handle(adev), i)) {
-			dev_dbg(&adev->dev,
-				"Link %d not selected in firmware\n", i);
-			continue;
-		}
-
-		info->link_mask |= BIT(i);
-	}
-
-	return 0;
-}
-
 #define HDA_DSP_REG_ADSPIC2             (0x10)
 #define HDA_DSP_REG_ADSPIS2             (0x14)
 #define HDA_DSP_REG_ADSPIC2_SNDW        BIT(5)
@@ -357,66 +259,6 @@ sdw_intel_startup_controller(struct sdw_intel_ctx *ctx)
 	return 0;
 }
 
-static acpi_status sdw_intel_acpi_cb(acpi_handle handle, u32 level,
-				     void *cdata, void **return_value)
-{
-	struct sdw_intel_acpi_info *info = cdata;
-	struct acpi_device *adev;
-	acpi_status status;
-	u64 adr;
-
-	status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &adr);
-	if (ACPI_FAILURE(status))
-		return AE_OK; /* keep going */
-
-	if (acpi_bus_get_device(handle, &adev)) {
-		pr_err("%s: Couldn't find ACPI handle\n", __func__);
-		return AE_NOT_FOUND;
-	}
-
-	info->handle = handle;
-
-	/*
-	 * On some Intel platforms, multiple children of the HDAS
-	 * device can be found, but only one of them is the SoundWire
-	 * controller. The SNDW device is always exposed with
-	 * Name(_ADR, 0x40000000), with bits 31..28 representing the
-	 * SoundWire link so filter accordingly
-	 */
-	if (FIELD_GET(GENMASK(31, 28), adr) != SDW_LINK_TYPE)
-		return AE_OK; /* keep going */
-
-	/* device found, stop namespace walk */
-	return AE_CTRL_TERMINATE;
-}
-
-/**
- * sdw_intel_acpi_scan() - SoundWire Intel init routine
- * @parent_handle: ACPI parent handle
- * @info: description of what firmware/DSDT tables expose
- *
- * This scans the namespace and queries firmware to figure out which
- * links to enable. A follow-up use of sdw_intel_probe() and
- * sdw_intel_startup() is required for creation of devices and bus
- * startup
- */
-int sdw_intel_acpi_scan(acpi_handle *parent_handle,
-			struct sdw_intel_acpi_info *info)
-{
-	acpi_status status;
-
-	info->handle = NULL;
-	status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
-				     parent_handle, 1,
-				     sdw_intel_acpi_cb,
-				     NULL, info, NULL);
-	if (ACPI_FAILURE(status) || info->handle == NULL)
-		return -ENODEV;
-
-	return sdw_intel_scan_controller(info);
-}
-EXPORT_SYMBOL_NS(sdw_intel_acpi_scan, SOUNDWIRE_INTEL_INIT);
-
 /**
  * sdw_intel_probe() - SoundWire Intel probe routine
  * @res: resource data

include/linux/soundwire/sdw_intel.h

@@ -187,4 +187,6 @@ void sdw_intel_enable_irq(void __iomem *mmio_base, bool enable);
 
 irqreturn_t sdw_intel_thread(int irq, void *dev_id);
 
+#define SDW_INTEL_QUIRK_MASK_BUS_DISABLE      BIT(1)
+
 #endif

sound/hda/Kconfig

@@ -44,9 +44,13 @@ config SND_INTEL_NHLT
 config SND_INTEL_DSP_CONFIG
 	tristate
 	select SND_INTEL_NHLT if ACPI
+	select SND_INTEL_SOUNDWIRE_ACPI if ACPI
 	# this config should be selected only for Intel DSP platforms.
 	# A fallback is provided so that the code compiles in all cases.
 
+config SND_INTEL_SOUNDWIRE_ACPI
+	tristate
+
 config SND_INTEL_BYT_PREFER_SOF
 	bool "Prefer SOF driver over SST on BY/CHT platforms"
 	depends on SND_SST_ATOM_HIFI2_PLATFORM_ACPI && SND_SOC_SOF_BAYTRAIL

sound/hda/Makefile

@@ -17,3 +17,6 @@ obj-$(CONFIG_SND_HDA_EXT_CORE) += ext/
 snd-intel-dspcfg-objs := intel-dsp-config.o
 snd-intel-dspcfg-$(CONFIG_SND_INTEL_NHLT) += intel-nhlt.o
 obj-$(CONFIG_SND_INTEL_DSP_CONFIG) += snd-intel-dspcfg.o
+
+snd-intel-sdw-acpi-objs := intel-sdw-acpi.o
+obj-$(CONFIG_SND_INTEL_SOUNDWIRE_ACPI) += snd-intel-sdw-acpi.o

sound/hda/intel-dsp-config.c

@@ -557,4 +557,4 @@ 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);
+MODULE_IMPORT_NS(SND_INTEL_SOUNDWIRE_ACPI);