Merge tag 'tags/sound-sdw-kconfig-fixes' into for-linus

ALSA/ASoC/SOF/SoundWire: fix Kconfig issues

In January, Intel kbuild bot and Arnd Bergmann reported multiple
issues with randconfig. This patchset builds on Arnd's suggestions to

a) expose ACPI and PCI devices in separate modules, while sof-acpi-dev
and sof-pci-dev become helpers. This will result in minor changes
required for developers/testers, i.e. modprobe snd-sof-pci will no
longer result in a probe. The SOF CI was already updated to deal with
this module dependency change and introduction of new modules.

b) Fix SOF/SoundWire/DSP_config dependencies by moving the code
required to detect SoundWire presence in ACPI tables to sound/hda.

Link: https://lore.kernel.org/r/20210302003125.1178419-1-pierre-louis.bossart@linux.intel.com

4 files changed, 187 insertions, 1 deletions

diff --git a/sound/hda/Kconfig b/sound/hda/Kconfig
index 9ed5cfa3c18c..57595f1552c9 100644
--- a/sound/hda/Kconfig
+++ b/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
diff --git a/sound/hda/Makefile b/sound/hda/Makefile
index 601e617918b8..78f487a635f8 100644
--- a/sound/hda/Makefile
+++ b/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
diff --git a/sound/hda/intel-dsp-config.c b/sound/hda/intel-dsp-config.c
index d1eb9d34993a..ab5ff7867eb9 100644
--- a/sound/hda/intel-dsp-config.c
+++ b/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);
diff --git a/sound/hda/intel-sdw-acpi.c b/sound/hda/intel-sdw-acpi.c
new file mode 100644
index 000000000000..c0123bc31c0d
--- /dev/null
+++ b/sound/hda/intel-sdw-acpi.c
@@ -0,0 +1,179 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+// Copyright(c) 2015-2021 Intel Corporation.
+
+/*
+ * SDW Intel ACPI scan helpers
+ */
+
+#include <linux/acpi.h>
+#include <linux/bits.h>
+#include <linux/bitfield.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/fwnode.h>
+#include <linux/module.h>
+#include <linux/soundwire/sdw_intel.h>
+#include <linux/string.h>
+
+#define SDW_LINK_TYPE		4 /* from Intel ACPI documentation */
+#define SDW_MAX_LINKS		4
+
+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_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;
+}
+
+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, SND_INTEL_SOUNDWIRE_ACPI);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_DESCRIPTION("Intel Soundwire ACPI helpers");