[PATCH v2 3/3] ASoC: SDCA: add a HID device for HIDE entity

[PATCH v2 3/3] ASoC: SDCA: add a HID device for HIDE entity

[shumingf]

From: Shuming Fan <shumingf@realtek.com>

This patch supports to add a HID device for SDCA HIDE entity.
The codec driver could call 'hid_input_report' to report events.

Signed-off-by: Shuming Fan <shumingf@realtek.com>
---
 include/sound/sdca_hid.h        |  25 +++++++
 sound/soc/sdca/Kconfig          |   4 +
 sound/soc/sdca/Makefile         |   3 +
 sound/soc/sdca/sdca_functions.c |   9 +++
 sound/soc/sdca/sdca_hid.c       | 127 ++++++++++++++++++++++++++++++++
 5 files changed, 168 insertions(+)
 create mode 100644 include/sound/sdca_hid.h
 create mode 100644 sound/soc/sdca/sdca_hid.c

diff --git a/include/sound/sdca_hid.h b/include/sound/sdca_hid.h
new file mode 100644
index 000000000000..8ab3e498884e
--- /dev/null
+++ b/include/sound/sdca_hid.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause) */
+/*
+ * The MIPI SDCA specification is available for public downloads at
+ * https://www.mipi.org/mipi-sdca-v1-0-download
+ *
+ */
+
+#ifndef __SDCA_HID_H__
+#define __SDCA_HID_H__
+
+#include <linux/types.h>
+#include <linux/hid.h>
+
+#if IS_ENABLED(CONFIG_SND_SOC_SDCA_HID)
+int sdca_add_hid_device(struct device *dev, struct sdca_entity *entity);
+
+#else
+static inline int sdca_add_hid_device(struct device *dev, struct sdca_entity *entity)
+{
+	return 0;
+}
+
+#endif
+
+#endif /* __SDCA_HID_H__ */
diff --git a/sound/soc/sdca/Kconfig b/sound/soc/sdca/Kconfig
index ee20b9914aa1..ec28855fe3b0 100644
--- a/sound/soc/sdca/Kconfig
+++ b/sound/soc/sdca/Kconfig
@@ -9,3 +9,7 @@ config SND_SOC_SDCA
 
 config SND_SOC_SDCA_OPTIONAL
 	def_tristate SND_SOC_SDCA || !SND_SOC_SDCA
+
+config SND_SOC_SDCA_HID
+	tristate "SDCA HID support"
+	depends on SND_SOC_SDCA && HID
diff --git a/sound/soc/sdca/Makefile b/sound/soc/sdca/Makefile
index 53344f108ca6..9af46e7edfd2 100644
--- a/sound/soc/sdca/Makefile
+++ b/sound/soc/sdca/Makefile
@@ -2,4 +2,7 @@
 
 snd-soc-sdca-y	:= sdca_functions.o sdca_device.o sdca_regmap.o sdca_asoc.o
 
+snd-soc-sdca-hid-y := sdca_hid.o
+
+obj-$(CONFIG_SND_SOC_SDCA_HID)	+= snd-soc-sdca-hid.o
 obj-$(CONFIG_SND_SOC_SDCA)	+= snd-soc-sdca.o
diff --git a/sound/soc/sdca/sdca_functions.c b/sound/soc/sdca/sdca_functions.c
index 4a89067dcf76..093c681e9387 100644
--- a/sound/soc/sdca/sdca_functions.c
+++ b/sound/soc/sdca/sdca_functions.c
@@ -19,6 +19,7 @@
 #include <linux/types.h>
 #include <sound/sdca.h>
 #include <sound/sdca_function.h>
+#include <sound/sdca_hid.h>
 
 /*
  * Should be long enough to encompass all the MIPI DisCo properties.
@@ -1294,6 +1295,13 @@ find_sdca_entity_hide(struct device *dev, struct fwnode_handle *function_node,
 			hide->hid_report_desc = report_desc;
 			fwnode_property_read_u8_array(function_node, "mipi-sdca-report-descriptor",
 						      report_desc, nval);
+
+			/* add HID device */
+			ret = sdca_add_hid_device(dev, entity);
+			if (ret) {
+				dev_err(dev, "%pfwP: failed to add HID device: %d\n", entity_node, ret);
+				return ret;
+			}
 		}
 	}
 
@@ -1933,3 +1941,4 @@ EXPORT_SYMBOL_NS(sdca_parse_function, "SND_SOC_SDCA");
 
 MODULE_LICENSE("Dual BSD/GPL");
 MODULE_DESCRIPTION("SDCA library");
+MODULE_IMPORT_NS("SND_SOC_SDCA_HID");
diff --git a/sound/soc/sdca/sdca_hid.c b/sound/soc/sdca/sdca_hid.c
new file mode 100644
index 000000000000..b227ad94d08f
--- /dev/null
+++ b/sound/soc/sdca/sdca_hid.c
@@ -0,0 +1,127 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+
+/*
+ * The MIPI SDCA specification is available for public downloads at
+ * https://www.mipi.org/mipi-sdca-v1-0-download
+ */
+
+#include <linux/acpi.h>
+#include <linux/byteorder/generic.h>
+#include <linux/cleanup.h>
+#include <linux/device.h>
+#include <linux/dev_printk.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/soundwire/sdw.h>
+#include <linux/types.h>
+#include <sound/sdca.h>
+#include <sound/sdca_function.h>
+#include <sound/sdca_hid.h>
+
+static int sdwhid_parse(struct hid_device *hid)
+{
+	struct sdca_entity *entity = hid->driver_data;
+	unsigned int rsize;
+	int ret;
+
+	rsize = entity->hide.hid_desc.rpt_desc.wDescriptorLength;
+
+	if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
+		dev_err(&hid->dev, "invalid size of report descriptor (%u)\n", rsize);
+		return -EINVAL;
+	}
+
+	ret = hid_parse_report(hid, entity->hide.hid_report_desc, rsize);
+
+	if (!ret)
+		return 0;
+
+	dev_err(&hid->dev, "parsing report descriptor failed\n");
+	return ret;
+}
+
+static int sdwhid_start(struct hid_device *hid)
+{
+	return 0;
+}
+
+static void sdwhid_stop(struct hid_device *hid)
+{
+}
+
+static int sdwhid_raw_request(struct hid_device *hid, unsigned char reportnum,
+			      __u8 *buf, size_t len, unsigned char rtype, int reqtype)
+{
+	switch (reqtype) {
+	case HID_REQ_GET_REPORT:
+		/* not implemented yet */
+		return 0;
+	case HID_REQ_SET_REPORT:
+		/* not implemented yet */
+		return 0;
+	default:
+		return -EIO;
+	}
+}
+
+static int sdwhid_open(struct hid_device *hid)
+{
+	return 0;
+}
+
+static void sdwhid_close(struct hid_device *hid)
+{
+}
+
+static const struct hid_ll_driver sdw_hid_driver = {
+	.parse = sdwhid_parse,
+	.start = sdwhid_start,
+	.stop = sdwhid_stop,
+	.open = sdwhid_open,
+	.close = sdwhid_close,
+	.raw_request = sdwhid_raw_request,
+};
+
+int sdca_add_hid_device(struct device *dev, struct sdca_entity *entity)
+{
+	struct sdw_bus *bus;
+	struct hid_device *hid;
+	struct sdw_slave *slave = dev_to_sdw_dev(dev);
+	int ret;
+
+	bus = slave->bus;
+
+	hid = hid_allocate_device();
+	if (IS_ERR(hid))
+		return PTR_ERR(hid);
+
+	hid->ll_driver = &sdw_hid_driver;
+
+	hid->dev.parent = dev;
+	hid->bus = BUS_SDW;
+	hid->version = le16_to_cpu(entity->hide.hid_desc.bcdHID);
+
+	snprintf(hid->name, sizeof(hid->name),
+		 "HID sdw:%01x:%01x:%04x:%04x:%02x",
+		 bus->controller_id, bus->link_id, slave->id.mfg_id,
+		 slave->id.part_id, slave->id.class_id);
+
+	snprintf(hid->phys, sizeof(hid->phys), "%s", dev->bus->name);
+
+	hid->driver_data = entity;
+
+	ret = hid_add_device(hid);
+	if (ret && ret != -ENODEV) {
+		dev_err(dev, "can't add hid device: %d\n", ret);
+		hid_destroy_device(hid);
+		return ret;
+	}
+
+	entity->hide.hid = hid;
+
+	return 0;
+}
+EXPORT_SYMBOL_NS(sdca_add_hid_device, "SND_SOC_SDCA_HID");
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_DESCRIPTION("SDCA HID library");
-- 
2.34.1

Re: [PATCH v2 3/3] ASoC: SDCA: add a HID device for HIDE entity

[Charles Keepax]

On Mon, Jun 16, 2025 at 07:49:29PM +0800, shumingf@realtek.com wrote:
> From: Shuming Fan <shumingf@realtek.com>
> 
> This patch supports to add a HID device for SDCA HIDE entity.
> The codec driver could call 'hid_input_report' to report events.
> 
> Signed-off-by: Shuming Fan <shumingf@realtek.com>
> ---

Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>

Thanks,
Charles

Re: [PATCH v2 3/3] ASoC: SDCA: add a HID device for HIDE entity

[Mark Brown]

On Mon, 16 Jun 2025 19:49:29 +0800, shumingf@realtek.com wrote:
> This patch supports to add a HID device for SDCA HIDE entity.
> The codec driver could call 'hid_input_report' to report events.
> 
> 

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next

Thanks!

[3/3] ASoC: SDCA: add a HID device for HIDE entity
      commit: ac558015dfd803626622bd0ba9645d58a3ed16b1

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark