HID: playstation: report DualSense hardware and firmware version.

Retrieve DualSense hardware and firmware information using a vendor
specific feature report. Report the data through sysfs and also
report using hid_info as there can be signficant differences between
versions.
Signed-off-by: Roderick Colenbrander <roderick.colenbrander@sony.com>
Reviewed-by: Barnabás Pőcze <pobrn@protonmail.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

drivers/hid/hid-playstation.c

@@ -34,6 +34,8 @@ struct ps_device {
 	int battery_status;
 
 	uint8_t mac_address[6]; /* Note: stored in little endian order. */
+	uint32_t hw_version;
+	uint32_t fw_version;
 
 	int (*parse_report)(struct ps_device *dev, struct hid_report *report, u8 *data, int size);
 };
@@ -64,6 +66,8 @@ struct ps_calibration_data {
 #define DS_FEATURE_REPORT_CALIBRATION_SIZE	41
 #define DS_FEATURE_REPORT_PAIRING_INFO		0x09
 #define DS_FEATURE_REPORT_PAIRING_INFO_SIZE	20
+#define DS_FEATURE_REPORT_FIRMWARE_INFO		0x20
+#define DS_FEATURE_REPORT_FIRMWARE_INFO_SIZE	64
 
 /* Button masks for DualSense input report. */
 #define DS_BUTTONS0_HAT_SWITCH	GENMASK(3, 0)
@@ -538,6 +542,40 @@ static struct input_dev *ps_touchpad_create(struct hid_device *hdev, int width,
 	return touchpad;
 }
 
+static ssize_t firmware_version_show(struct device *dev,
+				struct device_attribute
+				*attr, char *buf)
+{
+	struct hid_device *hdev = to_hid_device(dev);
+	struct ps_device *ps_dev = hid_get_drvdata(hdev);
+
+	return sysfs_emit(buf, "0x%08x\n", ps_dev->fw_version);
+}
+
+static DEVICE_ATTR_RO(firmware_version);
+
+static ssize_t hardware_version_show(struct device *dev,
+				struct device_attribute
+				*attr, char *buf)
+{
+	struct hid_device *hdev = to_hid_device(dev);
+	struct ps_device *ps_dev = hid_get_drvdata(hdev);
+
+	return sysfs_emit(buf, "0x%08x\n", ps_dev->hw_version);
+}
+
+static DEVICE_ATTR_RO(hardware_version);
+
+static struct attribute *ps_device_attributes[] = {
+	&dev_attr_firmware_version.attr,
+	&dev_attr_hardware_version.attr,
+	NULL
+};
+
+static const struct attribute_group ps_device_attribute_group = {
+	.attrs = ps_device_attributes,
+};
+
 static int dualsense_get_calibration_data(struct dualsense *ds)
 {
 	short gyro_pitch_bias, gyro_pitch_plus, gyro_pitch_minus;
@@ -628,6 +666,30 @@ static int dualsense_get_calibration_data(struct dualsense *ds)
 	return ret;
 }
 
+static int dualsense_get_firmware_info(struct dualsense *ds)
+{
+	uint8_t *buf;
+	int ret;
+
+	buf = kzalloc(DS_FEATURE_REPORT_FIRMWARE_INFO_SIZE, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	ret = ps_get_report(ds->base.hdev, DS_FEATURE_REPORT_FIRMWARE_INFO, buf,
+			DS_FEATURE_REPORT_FIRMWARE_INFO_SIZE);
+	if (ret) {
+		hid_err(ds->base.hdev, "Failed to retrieve DualSense firmware info: %d\n", ret);
+		goto err_free;
+	}
+
+	ds->base.hw_version = get_unaligned_le32(&buf[24]);
+	ds->base.fw_version = get_unaligned_le32(&buf[28]);
+
+err_free:
+	kfree(buf);
+	return ret;
+}
+
 static int dualsense_get_mac_address(struct dualsense *ds)
 {
 	uint8_t *buf;
@@ -956,6 +1018,12 @@ static struct ps_device *dualsense_create(struct hid_device *hdev)
 	}
 	snprintf(hdev->uniq, sizeof(hdev->uniq), "%pMR", ds->base.mac_address);
 
+	ret = dualsense_get_firmware_info(ds);
+	if (ret) {
+		hid_err(hdev, "Failed to get firmware info from DualSense\n");
+		return ERR_PTR(ret);
+	}
+
 	ret = ps_devices_list_add(ps_dev);
 	if (ret)
 		return ERR_PTR(ret);
@@ -989,6 +1057,13 @@ static struct ps_device *dualsense_create(struct hid_device *hdev)
 	if (ret)
 		goto err;
 
+	/*
+	 * Reporting hardware and firmware is important as there are frequent updates, which
+	 * can change behavior.
+	 */
+	hid_info(hdev, "Registered DualSense controller hw_version=0x%08x fw_version=0x%08x\n",
+			ds->base.hw_version, ds->base.fw_version);
+
 	return &ds->base;
 
 err:
@@ -1039,6 +1114,12 @@ static int ps_probe(struct hid_device *hdev, const struct hid_device_id *id)
 		}
 	}
 
+	ret = devm_device_add_group(&hdev->dev, &ps_device_attribute_group);
+	if (ret) {
+		hid_err(hdev, "Failed to register sysfs nodes.\n");
+		goto err_close;
+	}
+
 	return ret;
 
 err_close: