[PATCH] HID: u2fzero: Support NitroKey U2F revision of the device

[Andrej Shadura <andrew.shadura@collabora.co.uk>]

NitroKey produced a clone of U2F Zero with a different firmware,
which moved extra commands into the vendor range.
Disambiguate hardware revisions and select the correct configuration in
u2fzero_probe.

Link: https://github.com/Nitrokey/nitrokey-fido-u2f-firmware/commit/a93c16b41f
Signed-off-by: Andrej Shadura <andrew.shadura@collabora.co.uk>
---
 drivers/hid/hid-ids.h     |  3 +++
 drivers/hid/hid-u2fzero.c | 45 +++++++++++++++++++++++++++++++--------
 2 files changed, 39 insertions(+), 9 deletions(-)

diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index 29564b370341..44459be66a5d 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -288,6 +288,9 @@
 #define USB_DEVICE_ID_CJTOUCH_MULTI_TOUCH_0020	0x0020
 #define USB_DEVICE_ID_CJTOUCH_MULTI_TOUCH_0040	0x0040
 
+#define USB_VENDOR_ID_CLAY_LOGIC	0x20a0
+#define USB_DEVICE_ID_NITROKEY_U2F	0x4287
+
 #define USB_VENDOR_ID_CMEDIA		0x0d8c
 #define USB_DEVICE_ID_CM109		0x000e
 #define USB_DEVICE_ID_CMEDIA_HS100B	0x0014
diff --git a/drivers/hid/hid-u2fzero.c b/drivers/hid/hid-u2fzero.c
index 67ae2b18e33a..31ea7fc69916 100644
--- a/drivers/hid/hid-u2fzero.c
+++ b/drivers/hid/hid-u2fzero.c
@@ -26,6 +26,30 @@
 
 #define HID_REPORT_SIZE		64
 
+enum hw_revision {
+	HW_U2FZERO,
+	HW_NITROKEY_U2F,
+};
+
+struct hw_revision_config {
+	u8 rng_cmd;
+	u8 wink_cmd;
+	const char *name;
+};
+
+static const struct hw_revision_config hw_configs[] = {
+	[HW_U2FZERO] = {
+		.rng_cmd  = 0x21,
+		.wink_cmd = 0x24,
+		.name = "U2F Zero",
+	},
+	[HW_NITROKEY_U2F] = {
+		.rng_cmd  = 0xc0,
+		.wink_cmd = 0xc2,
+		.name = "NitroKey U2F",
+	},
+};
+
 /* We only use broadcast (CID-less) messages */
 #define CID_BROADCAST		0xffffffff
 
@@ -52,10 +76,6 @@ struct u2f_hid_report {
 
 #define U2F_HID_MSG_LEN(f)	(size_t)(((f).init.bcnth << 8) + (f).init.bcntl)
 
-/* Custom extensions to the U2FHID protocol */
-#define U2F_CUSTOM_GET_RNG	0x21
-#define U2F_CUSTOM_WINK		0x24
-
 struct u2fzero_device {
 	struct hid_device	*hdev;
 	struct urb		*urb;	    /* URB for the RNG data */
@@ -67,6 +87,7 @@ struct u2fzero_device {
 	u8			*buf_in;
 	struct mutex		lock;
 	bool			present;
+	kernel_ulong_t		hw_revision;
 };
 
 static int u2fzero_send(struct u2fzero_device *dev, struct u2f_hid_report *req)
@@ -154,7 +175,7 @@ static int u2fzero_blink(struct led_classdev *ldev)
 		.report_type = 0,
 		.msg.cid = CID_BROADCAST,
 		.msg.init = {
-			.cmd = U2F_CUSTOM_WINK,
+			.cmd = hw_configs[dev->hw_revision].wink_cmd,
 			.bcnth = 0,
 			.bcntl = 0,
 			.data  = {0},
@@ -182,7 +203,7 @@ static int u2fzero_rng_read(struct hwrng *rng, void *data,
 		.report_type = 0,
 		.msg.cid = CID_BROADCAST,
 		.msg.init = {
-			.cmd = U2F_CUSTOM_GET_RNG,
+			.cmd = hw_configs[dev->hw_revision].rng_cmd,
 			.bcnth = 0,
 			.bcntl = 0,
 			.data  = {0},
@@ -297,6 +318,8 @@ static int u2fzero_probe(struct hid_device *hdev,
 	if (dev == NULL)
 		return -ENOMEM;
 
+	dev->hw_revision = id->driver_data;
+
 	dev->buf_out = devm_kmalloc(&hdev->dev,
 		sizeof(struct u2f_hid_report), GFP_KERNEL);
 	if (dev->buf_out == NULL)
@@ -331,7 +354,7 @@ static int u2fzero_probe(struct hid_device *hdev,
 		return ret;
 	}
 
-	hid_info(hdev, "U2F Zero LED initialised\n");
+	hid_info(hdev, "%s LED initialised\n", hw_configs[dev->hw_revision].name);
 
 	ret = u2fzero_init_hwrng(dev, minor);
 	if (ret) {
@@ -339,7 +362,7 @@ static int u2fzero_probe(struct hid_device *hdev,
 		return ret;
 	}
 
-	hid_info(hdev, "U2F Zero RNG initialised\n");
+	hid_info(hdev, "%s RNG initialised\n", hw_configs[dev->hw_revision].name);
 
 	return 0;
 }
@@ -359,7 +382,11 @@ static void u2fzero_remove(struct hid_device *hdev)
 
 static const struct hid_device_id u2fzero_table[] = {
 	{ HID_USB_DEVICE(USB_VENDOR_ID_CYGNAL,
-	  USB_DEVICE_ID_U2F_ZERO) },
+	  USB_DEVICE_ID_U2F_ZERO),
+	  .driver_data = HW_U2FZERO },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_CLAY_LOGIC,
+	  USB_DEVICE_ID_NITROKEY_U2F),
+	  .driver_data = HW_NITROKEY_U2F },
 	{ }
 };
 MODULE_DEVICE_TABLE(hid, u2fzero_table);
-- 
2.33.0