New subject: [PATCH v2] ALSA: hda - Add new driver for HDA controllers listed via ACPI

15 May 2025

Some systems expose HD-Audio controllers via objects in the ACPI tables
which encapsulate the controller's interrupt and the base address for the
HDA registers in an ACPI _CRS object, for example, as listed in this ACPI
table dump excerpt:
Device (HDA0)
        {
            Name (_HID, "NVDA2014")  // _HID: Hardware ID
            ...
            Name (_CRS, ResourceTemplate ()  // _CRS: Current Resource Settings
            {
                Memory32Fixed (ReadWrite,
                    0x36078000,         // Address Base
                    0x00008000,         // Address Length
                    )
                Interrupt (ResourceConsumer, Level, ActiveHigh, Exclusive, ,, )
                {
                    0x0000021E,
                }
            })
        }
Add support for HDA controllers discovered through ACPI, including support
for some platforms which expose such HDA controllers on NVIDIA SoCs. This
is done with a new driver which uses existing infrastructure for extracting
resource information from _CRS objects and plumbs the parsed resource
information through to the existing HDA infrastructure to enable HD-Audio
functionality on such devices.
Although this driver is in the sound/pci/hda/ directory, it targets devices
which are not actually enumerated on the PCI bus. This is because it depends
upon the Intel "Azalia" infrastructure which has traditionally been used for
PCI-based devices.
Signed-off-by: Daniel Dadap ddadap@nvidia.com
---
 sound/pci/hda/Kconfig    |  11 ++
 sound/pci/hda/Makefile   |   2 +
 sound/pci/hda/hda_acpi.c | 316 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 329 insertions(+)
 create mode 100644 sound/pci/hda/hda_acpi.c

diff --git a/sound/pci/hda/Kconfig b/sound/pci/hda/Kconfig
index 9c427270ff4f..436dfd182a09 100644
--- a/sound/pci/hda/Kconfig
+++ b/sound/pci/hda/Kconfig
@@ -42,6 +42,17 @@ config SND_HDA_TEGRA
      To compile this driver as a module, choose M here: the module
      will be called snd-hda-tegra.
+config SND_HDA_ACPI
+	tristate "HD Audio ACPI"
+	depends on ACPI
+	select SND_HDA
+	help
+	  Say Y here to include support for Azalia-compatible HDA controllers
+	  which are advertised via ACPI objects.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called snd-hda-acpi.
+
 if SND_HDA
config SND_HDA_HWDEP
diff --git a/sound/pci/hda/Makefile b/sound/pci/hda/Makefile
index 210c406dfbc5..7a7c16d705dd 100644
--- a/sound/pci/hda/Makefile
+++ b/sound/pci/hda/Makefile
@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 snd-hda-intel-y := hda_intel.o
 snd-hda-tegra-y := hda_tegra.o
+snd-hda-acpi-y := hda_acpi.o
snd-hda-codec-y := hda_bind.o hda_codec.o hda_jack.o hda_auto_parser.o hda_sysfs.o
 snd-hda-codec-y += hda_controller.o
@@ -80,3 +81,4 @@ obj-$(CONFIG_SND_HDA_SCODEC_TAS2781_SPI) += snd-hda-scodec-tas2781-spi.o
 # when built in kernel
 obj-$(CONFIG_SND_HDA_INTEL) += snd-hda-intel.o
 obj-$(CONFIG_SND_HDA_TEGRA) += snd-hda-tegra.o
+obj-$(CONFIG_SND_HDA_ACPI) += snd-hda-acpi.o
diff --git a/sound/pci/hda/hda_acpi.c b/sound/pci/hda/hda_acpi.c
new file mode 100644
index 000000000000..736eac59eaa0
--- /dev/null
+++ b/sound/pci/hda/hda_acpi.c
@@ -0,0 +1,316 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ALSA driver for ACPI-based HDA Controllers.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/acpi.h>
+
+#include <sound/hda_codec.h>
+
+#include "hda_controller.h"
+
+struct hda_acpi {
+	struct azx azx;
+	struct snd_card *card;
+	struct platform_device *pdev;
+	void __iomem *regs;
+	struct work_struct probe_work;
+	const struct hda_data *data;
+};
+
+/**
+ * struct hda_data - Optional device-specific data
+ * @short_name: Used for the ALSA card name; defaults to KBUILD_MODNAME
+ * @long_name:  Used for longer description; defaults to short_name
+ * @flags:      Passed to &azx->driver_caps
+ *
+ * A pointer to a record of this type may be stored in the
+ * &acpi_device_id->driver_data field of an ACPI match table entry in order to
+ * customize the naming and behavior of a particular device. All fields are
+ * optional and sensible defaults will be selected in their absence.
+ */
+struct hda_data {
+	const char *short_name;
+	const char *long_name;
+	unsigned long flags;
+};
+
+static int hda_acpi_dev_disconnect(struct snd_device *device)
+{
+	struct azx *chip = device->device_data;
+
+	chip->bus.shutdown = 1;
+	return 0;
+}
+
+static int hda_acpi_dev_free(struct snd_device *device)
+{
+	struct azx *azx = device->device_data;
+	struct hda_acpi *hda = container_of(azx, struct hda_acpi, azx);
+
+	cancel_work_sync(&hda->probe_work);
+	if (azx_bus(azx)->chip_init) {
+		azx_stop_all_streams(azx);
+		azx_stop_chip(azx);
+	}
+
+	azx_free_stream_pages(azx);
+	azx_free_streams(azx);
+	snd_hdac_bus_exit(azx_bus(azx));
+
+	return 0;
+}
+
+static int hda_acpi_init(struct hda_acpi *hda)
+{
+	struct hdac_bus *bus = azx_bus(&hda->azx);
+	struct snd_card *card = hda->azx.card;
+	struct device *dev = &hda->pdev->dev;
+	struct azx *azx = &hda->azx;
+	struct resource *res;
+	unsigned short gcap;
+	const char *sname, *lname;
+	int err, irq;
+
+	/* The base address for the HDA registers and the interrupt are wrapped
+	 * in an ACPI _CRS object which can be parsed by platform_get_irq() and
+	 * devm_platform_get_and_ioremap_resource() */
+
+	irq = platform_get_irq(hda->pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	hda->regs = devm_platform_get_and_ioremap_resource(hda->pdev, 0, &res);
+	if (IS_ERR(hda->regs))
+		return PTR_ERR(hda->regs);
+
+	bus->remap_addr = hda->regs;
+	bus->addr = res->start;
+
+	err = devm_request_irq(dev, irq, azx_interrupt,
+	                       IRQF_SHARED, KBUILD_MODNAME, azx);
+	if (err) {
+		dev_err(dev, "unable to request IRQ %d, disabling device\n", irq);
+		return err;
+	}
+	bus->irq = irq;
+	bus->dma_stop_delay = 100;
+	card->sync_irq = bus->irq;
+
+	gcap = azx_readw(azx, GCAP);
+	dev_dbg(dev, "chipset global capabilities = 0x%x\n", gcap);
+
+	azx->align_buffer_size = 1;
+
+	azx->capture_streams = (gcap >> 8) & 0x0f;
+	azx->playback_streams = (gcap >> 12) & 0x0f;
+
+	azx->capture_index_offset = 0;
+	azx->playback_index_offset = azx->capture_streams;
+	azx->num_streams = azx->playback_streams + azx->capture_streams;
+
+	err = azx_init_streams(azx);
+	if (err < 0) {
+		dev_err(dev, "failed to initialize streams: %d\n", err);
+		return err;
+	}
+
+	err = azx_alloc_stream_pages(azx);
+	if (err < 0) {
+		dev_err(dev, "failed to allocate stream pages: %d\n", err);
+		return err;
+	}
+
+	azx_init_chip(azx, 1);
+
+	if (!bus->codec_mask) {
+		dev_err(dev, "no codecs found!\n");
+		return -ENODEV;
+	}
+
+	strscpy(card->driver, "hda-acpi", sizeof(card->driver));
+
+	sname = hda->data->short_name ? hda->data->short_name : KBUILD_MODNAME;
+
+	if (strlen(sname) > sizeof(card->shortname))
+		dev_info(dev, "truncating shortname for card %s\n", sname);
+	strscpy(card->shortname, sname, sizeof(card->shortname));
+
+	lname = hda->data->long_name ? hda->data->long_name : sname;
+
+	snprintf(card->longname, sizeof(card->longname),
+		 "%s at 0x%lx irq %i", lname, bus->addr, bus->irq);
+
+	return 0;
+}
+
+static void hda_acpi_probe_work(struct work_struct *work)
+{
+	struct hda_acpi *hda = container_of(work, struct hda_acpi, probe_work);
+	struct azx *chip = &hda->azx;
+	int err;
+
+	err = hda_acpi_init(hda);
+	if (err < 0)
+		return;
+
+	err = azx_probe_codecs(chip, 8);
+	if (err < 0)
+		return;
+
+	err = azx_codec_configure(chip);
+	if (err < 0)
+		return;
+
+	err = snd_card_register(chip->card);
+	if (err < 0)
+		return;
+
+	chip->running = 1;
+}
+
+static int hda_acpi_create(struct hda_acpi *hda)
+{
+	static const struct snd_device_ops ops = {
+		.dev_disconnect = hda_acpi_dev_disconnect,
+		.dev_free = hda_acpi_dev_free,
+	};
+	static const struct hda_controller_ops null_ops;
+	struct azx *azx = &hda->azx;
+	int err;
+
+	mutex_init(&azx->open_mutex);
+	azx->card = hda->card;
+	INIT_LIST_HEAD(&azx->pcm_list);
+
+	azx->ops = &null_ops;
+	azx->driver_caps = hda->data->flags;
+	azx->driver_type = hda->data->flags & 0xff;
+	azx->codec_probe_mask = -1;
+
+	err = azx_bus_init(azx, NULL);
+	if (err < 0)
+		return err;
+
+	err = snd_device_new(hda->card, SNDRV_DEV_LOWLEVEL, &hda->azx, &ops);
+	if (err < 0) {
+		dev_err(&hda->pdev->dev, "Error creating device\n");
+		return err;
+	}
+
+	return 0;
+}
+
+static int hda_acpi_probe(struct platform_device *pdev)
+{
+	struct hda_acpi *hda;
+	int err;
+
+	hda = devm_kzalloc(&pdev->dev, sizeof(*hda), GFP_KERNEL);
+	if (!hda)
+		return -ENOMEM;
+
+	hda->pdev = pdev;
+	hda->data = acpi_device_get_match_data(&pdev->dev);
+
+	err = snd_card_new(&pdev->dev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1,
+	                   THIS_MODULE, 0, &hda->card);
+	if (err < 0) {
+		dev_err(&pdev->dev, "Error creating card!\n");
+		return err;
+	}
+
+	INIT_WORK(&hda->probe_work, hda_acpi_probe_work);
+
+	err = hda_acpi_create(hda);
+	if (err < 0)
+		goto out_free;
+	hda->card->private_data = &hda->azx;
+
+	dev_set_drvdata(&pdev->dev, hda->card);
+
+	schedule_work(&hda->probe_work);
+
+	return 0;
+
+out_free:
+	snd_card_free(hda->card);
+	return err;
+}
+
+static void hda_acpi_remove(struct platform_device *pdev)
+{
+	snd_card_free(dev_get_drvdata(&pdev->dev));
+}
+
+static void hda_acpi_shutdown(struct platform_device *pdev)
+{
+	struct snd_card *card = dev_get_drvdata(&pdev->dev);
+	struct azx *chip;
+
+	if (!card)
+		return;
+	chip = card->private_data;
+	if (chip && chip->running)
+		azx_stop_chip(chip);
+}
+
+static int __maybe_unused hda_acpi_suspend(struct device *dev)
+{
+	struct snd_card *card = dev_get_drvdata(dev);
+	int rc;
+
+	rc = pm_runtime_force_suspend(dev);
+	if (rc < 0)
+		return rc;
+	snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
+
+	return 0;
+}
+
+static int __maybe_unused hda_acpi_resume(struct device *dev)
+{
+	struct snd_card *card = dev_get_drvdata(dev);
+	int rc;
+
+	rc = pm_runtime_force_resume(dev);
+	if (rc < 0)
+		return rc;
+	snd_power_change_state(card, SNDRV_CTL_POWER_D0);
+
+	return 0;
+}
+
+static const struct dev_pm_ops hda_acpi_pm = {
+	SET_SYSTEM_SLEEP_PM_OPS(hda_acpi_suspend, hda_acpi_resume)
+};
+
+struct hda_data nvidia_hda_data = {
+	.short_name = "NVIDIA",
+	.long_name = "NVIDIA HDA Controller",
+	.flags = AZX_DCAPS_CORBRP_SELF_CLEAR,
+};
+
+static const struct acpi_device_id hda_acpi_match[] = {
+	{ .id = "NVDA2014", .driver_data = (uintptr_t) &nvidia_hda_data },
+	{ .id = "NVDA2015", .driver_data = (uintptr_t) &nvidia_hda_data },
+	{},
+};
+MODULE_DEVICE_TABLE(acpi, hda_acpi_match);
+
+static struct platform_driver hda_acpi_platform_driver = {
+	.driver = {
+		.name = KBUILD_MODNAME,
+		.pm = &hda_acpi_pm,
+		.acpi_match_table = hda_acpi_match,
+	},
+	.probe = hda_acpi_probe,
+	.remove = hda_acpi_remove,
+	.shutdown = hda_acpi_shutdown,
+};
+module_platform_driver(hda_acpi_platform_driver);
+
+MODULE_DESCRIPTION("Driver for ACPI-based HDA Controllers");
+MODULE_LICENSE("GPL v2");
-- 
2.39.5


    

[PATCH] ALSA: hda - Add new driver for HDA controllers listed via ACPI

Daniel Dadap

Takashi Iwai

Takashi Iwai

Daniel Dadap

Daniel Dadap

Daniel Dadap

Takashi Iwai

Daniel Dadap

Daniel Dadap

Takashi Iwai

Daniel Dadap

Daniel Dadap

Daniel Dadap

Daniel Dadap

Takashi Iwai

Signed-off-by: Daniel Dadap ddadap@nvidia.com

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