[PATCH 02/13] HID: playstation: use DualSense MAC address as unique identifier.

[Roderick Colenbrander <roderick@gaikai.com>]

From: Roderick Colenbrander <roderick.colenbrander@sony.com>

Use the DualSense MAC address as a unique identifier for the HID device.

Signed-off-by: Roderick Colenbrander <roderick.colenbrander@sony.com>
---
 drivers/hid/hid-playstation.c | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/drivers/hid/hid-playstation.c b/drivers/hid/hid-playstation.c
index 8dbd0ae7e082..88823a7ba1a0 100644
--- a/drivers/hid/hid-playstation.c
+++ b/drivers/hid/hid-playstation.c
@@ -17,12 +17,16 @@
 /* Base class for playstation devices. */
 struct ps_device {
 	struct hid_device *hdev;
+	uint8_t mac_address[6];
 
 	int (*parse_report)(struct ps_device *dev, struct hid_report *report, u8 *data, int size);
 };
 
 #define DS_INPUT_REPORT_USB			0x01
 
+#define DS_FEATURE_REPORT_PAIRING_INFO		9
+#define DS_FEATURE_REPORT_PAIRING_INFO_SIZE	19
+
 /* Button masks for DualSense input report. */
 #define DS_BUTTONS0_HAT_SWITCH	GENMASK(3, 0)
 #define DS_BUTTONS0_SQUARE	BIT(4)
@@ -127,6 +131,7 @@ static struct input_dev *ps_allocate_input_dev(struct hid_device *hdev, const ch
 	return input_dev;
 }
 
+
 static struct input_dev *ps_gamepad_create(struct hid_device *hdev)
 {
 	struct input_dev *gamepad;
@@ -157,6 +162,29 @@ static struct input_dev *ps_gamepad_create(struct hid_device *hdev)
 	return gamepad;
 }
 
+static int dualsense_get_mac_address(struct dualsense *ds)
+{
+	uint8_t *buf;
+	int ret = 0;
+
+	buf = kzalloc(DS_FEATURE_REPORT_PAIRING_INFO_SIZE, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	ret = hid_hw_raw_request(ds->base.hdev, DS_FEATURE_REPORT_PAIRING_INFO, buf,
+			DS_FEATURE_REPORT_PAIRING_INFO_SIZE, HID_FEATURE_REPORT,
+			HID_REQ_GET_REPORT);
+	if (ret < 0)
+		goto err_free;
+
+	/* Note MAC address is stored in little endian order. */
+	memcpy(ds->base.mac_address, &buf[1], sizeof(ds->base.mac_address));
+
+err_free:
+	kfree(buf);
+	return ret;
+}
+
 static int dualsense_parse_report(struct ps_device *ps_dev, struct hid_report *report,
 		u8 *data, int size)
 {
@@ -225,6 +253,13 @@ static struct ps_device *dualsense_create(struct hid_device *hdev)
 	ds->base.parse_report = dualsense_parse_report;
 	hid_set_drvdata(hdev, ds);
 
+	ret = dualsense_get_mac_address(ds);
+	if (ret < 0) {
+		hid_err(hdev, "Failed to get MAC address from DualSense\n");
+		return ERR_PTR(ret);
+	}
+	snprintf(hdev->uniq, sizeof(hdev->uniq), "%pMR", ds->base.mac_address);
+
 	ds->gamepad = ps_gamepad_create(hdev);
 	if (IS_ERR(ds->gamepad)) {
 		ret = PTR_ERR(ds->gamepad);
-- 
2.26.2