HID: i2c-hid: implement ll_driver transport-layer callbacks

Add output_report and raw_request to i2c-hid.
The current implementation of i2c_hid_output_raw_report decides
by itself if it should use a direct send of the output report
or use the data register (SET_REPORT). Split that by reimplement
the logic in __i2c_hid_output_raw_report() which will be dropped
soon.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/i2c-hid/i2c-hid.c

@@ -256,12 +256,21 @@ static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
 	return 0;
 }
 
-static int i2c_hid_set_report(struct i2c_client *client, u8 reportType,
-		u8 reportID, unsigned char *buf, size_t data_len)
+/**
+ * i2c_hid_set_or_send_report: forward an incoming report to the device
+ * @client: the i2c_client of the device
+ * @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
+ * @reportID: the report ID
+ * @buf: the actual data to transfer, without the report ID
+ * @len: size of buf
+ * @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report
+ */
+static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType,
+		u8 reportID, unsigned char *buf, size_t data_len, bool use_data)
 {
 	struct i2c_hid *ihid = i2c_get_clientdata(client);
 	u8 *args = ihid->argsbuf;
-	const struct i2c_hid_cmd * hidcmd = &hid_set_report_cmd;
+	const struct i2c_hid_cmd *hidcmd;
 	int ret;
 	u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
 	u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister);
@@ -278,6 +287,9 @@ static int i2c_hid_set_report(struct i2c_client *client, u8 reportType,
 
 	i2c_hid_dbg(ihid, "%s\n", __func__);
 
+	if (!use_data && maxOutputLength == 0)
+		return -ENOSYS;
+
 	if (reportID >= 0x0F) {
 		args[index++] = reportID;
 		reportID = 0x0F;
@@ -287,9 +299,10 @@ static int i2c_hid_set_report(struct i2c_client *client, u8 reportType,
 	 * use the data register for feature reports or if the device does not
 	 * support the output register
 	 */
-	if (reportType == 0x03 || maxOutputLength == 0) {
+	if (use_data) {
 		args[index++] = dataRegister & 0xFF;
 		args[index++] = dataRegister >> 8;
+		hidcmd = &hid_set_report_cmd;
 	} else {
 		args[index++] = outputRegister & 0xFF;
 		args[index++] = outputRegister >> 8;
@@ -550,7 +563,7 @@ static int i2c_hid_get_raw_report(struct hid_device *hid,
 }
 
 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
-		size_t count, unsigned char report_type)
+		size_t count, unsigned char report_type, bool use_data)
 {
 	struct i2c_client *client = hid->driver_data;
 	int report_id = buf[0];
@@ -564,9 +577,9 @@ static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
 		count--;
 	}
 
-	ret = i2c_hid_set_report(client,
+	ret = i2c_hid_set_or_send_report(client,
 				report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
-				report_id, buf, count);
+				report_id, buf, count, use_data);
 
 	if (report_id && ret >= 0)
 		ret++; /* add report_id to the number of transfered bytes */
@@ -574,6 +587,42 @@ static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
 	return ret;
 }
 
+static int __i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
+		size_t count, unsigned char report_type)
+{
+	struct i2c_client *client = hid->driver_data;
+	struct i2c_hid *ihid = i2c_get_clientdata(client);
+	bool data = true; /* SET_REPORT */
+
+	if (report_type == HID_OUTPUT_REPORT)
+		data = le16_to_cpu(ihid->hdesc.wMaxOutputLength) == 0;
+
+	return i2c_hid_output_raw_report(hid, buf, count, report_type, data);
+}
+
+static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf,
+		size_t count)
+{
+	return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT,
+			false);
+}
+
+static int i2c_hid_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:
+		return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype);
+	case HID_REQ_SET_REPORT:
+		if (buf[0] != reportnum)
+			return -EINVAL;
+		return i2c_hid_output_raw_report(hid, buf, len, rtype, true);
+	default:
+		return -EIO;
+	}
+}
+
 static void i2c_hid_request(struct hid_device *hid, struct hid_report *rep,
 		int reqtype)
 {
@@ -597,7 +646,7 @@ static void i2c_hid_request(struct hid_device *hid, struct hid_report *rep,
 		break;
 	case HID_REQ_SET_REPORT:
 		hid_output_report(rep, buf);
-		i2c_hid_output_raw_report(hid, buf, len, rep->type);
+		i2c_hid_output_raw_report(hid, buf, len, rep->type, true);
 		break;
 	}
 
@@ -761,6 +810,8 @@ static struct hid_ll_driver i2c_hid_ll_driver = {
 	.close = i2c_hid_close,
 	.power = i2c_hid_power,
 	.request = i2c_hid_request,
+	.output_report = i2c_hid_output_report,
+	.raw_request = i2c_hid_raw_request,
 };
 
 static int i2c_hid_init_irq(struct i2c_client *client)
@@ -1005,7 +1056,7 @@ static int i2c_hid_probe(struct i2c_client *client,
 
 	hid->driver_data = client;
 	hid->ll_driver = &i2c_hid_ll_driver;
-	hid->hid_output_raw_report = i2c_hid_output_raw_report;
+	hid->hid_output_raw_report = __i2c_hid_output_raw_report;
 	hid->dev.parent = &client->dev;
 	ACPI_COMPANION_SET(&hid->dev, ACPI_COMPANION(&client->dev));
 	hid->bus = BUS_I2C;