ASoC: SDCA: register a HID device for HIDE entity

This patch registers 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>

Author: shumingfan

sound/soc/sdca/sdca_functions.c

@@ -1222,6 +1222,124 @@ static int find_sdca_entity_ge(struct device *dev,
 	return -EINVAL;
 }
 
+static int sdwhid_parse(struct hid_device *hid)
+{
+	//struct sdw_slave *slave = dev_to_sdw_dev(hid->dev.parent);
+	struct sdca_entity *entity = hid->driver_data;
+	unsigned int rsize = 0;
+	char *rdesc;
+	int ret;
+
+	rsize = entity->hide.hid_desc.desc[0].wDescriptorLength;
+
+	if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
+		dev_err(&hid->dev, "weird size of report descriptor (%u)\n", rsize);
+		return -EINVAL;
+	}
+
+	rdesc = kmalloc(rsize, GFP_KERNEL);
+	if (!rdesc)
+		return -ENOMEM;
+
+	memcpy(rdesc, entity->hide.hid_report_desc, rsize);
+
+	ret = hid_parse_report(hid, rdesc, rsize);
+	kfree(rdesc);
+	if (ret) {
+		dev_err(&hid->dev, "parsing report descriptor failed\n");
+		goto err;
+	}
+
+	return 0;
+err:
+	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 usbhid_get_raw_report(hid, reportnum, buf, len, rtype);
+		printk("%s: HID_REQ_GET_REPORT not implemented\n", __func__);
+		return 0;
+	case HID_REQ_SET_REPORT:
+		/* not implemented yet */
+		//return usbhid_set_raw_report(hid, reportnum, buf, len, rtype);
+		printk("%s: HID_REQ_SET_REPORT not implemented\n", __func__);
+		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,
+};
+
+static int register_sdw_hid_device(struct device *dev, struct fwnode_handle *entity_node,
+	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->name[0] = 0;
+	if (!strlen(hid->name))
+		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);
+
+	hid->driver_data = entity;
+
+	ret = hid_add_device(hid);
+	if (ret) {
+		if (ret != -ENODEV)
+			dev_err(dev, "can't add hid device: %d\n", ret);
+	}
+
+	entity->hide.hid = hid;
+
+	return 0;
+}
+
 static int find_sdca_entity_hide(struct device *dev, struct fwnode_handle *function_node,
 	struct fwnode_handle *entity_node, struct sdca_entity *entity)
 {
@@ -1305,6 +1423,9 @@ static int find_sdca_entity_hide(struct device *dev, struct fwnode_handle *funct
 	hide->hid_report_desc = report_desc;
 	fwnode_property_read_u8_array(function_node, "mipi-sdca-report-descriptor", report_desc, num_report_decs);
 
+	/* register HID device */
+	register_sdw_hid_device(dev, entity_node, entity);
+
 	return 0;
 }