[PATCH v3 1/2] hid-asus: check ROG Ally MCU version and warn

[Luke Jones <luke@ljones.dev>]

From: "Luke D. Jones" <luke@ljones.dev>

ASUS have fixed suspend issues arising from a flag not being cleared in
the MCU FW in both the ROG Ally 1 and the ROG Ally X.

Implement a check and a warning to encourage users to update the FW to
a minimum supported version.

Signed-off-by: Luke D. Jones <luke@ljones.dev>
---
 drivers/hid/hid-asus.c | 107 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 105 insertions(+), 2 deletions(-)

diff --git a/drivers/hid/hid-asus.c b/drivers/hid/hid-asus.c
index 46e3e42f9eb5..599c836507ff 100644
--- a/drivers/hid/hid-asus.c
+++ b/drivers/hid/hid-asus.c
@@ -52,6 +52,10 @@ MODULE_DESCRIPTION("Asus HID Keyboard and TouchPad");
 #define FEATURE_KBD_LED_REPORT_ID1 0x5d
 #define FEATURE_KBD_LED_REPORT_ID2 0x5e
 
+#define ROG_ALLY_REPORT_SIZE 64
+#define ROG_ALLY_X_MIN_MCU 313
+#define ROG_ALLY_MIN_MCU 319
+
 #define SUPPORT_KBD_BACKLIGHT BIT(0)
 
 #define MAX_TOUCH_MAJOR 8
@@ -84,6 +88,7 @@ MODULE_DESCRIPTION("Asus HID Keyboard and TouchPad");
 #define QUIRK_MEDION_E1239T		BIT(10)
 #define QUIRK_ROG_NKEY_KEYBOARD		BIT(11)
 #define QUIRK_ROG_CLAYMORE_II_KEYBOARD BIT(12)
+#define QUIRK_ROG_ALLY_XPAD		BIT(13)
 
 #define I2C_KEYBOARD_QUIRKS			(QUIRK_FIX_NOTEBOOK_REPORT | \
 						 QUIRK_NO_INIT_REPORTS | \
@@ -534,9 +539,99 @@ static bool asus_kbd_wmi_led_control_present(struct hid_device *hdev)
 	return !!(value & ASUS_WMI_DSTS_PRESENCE_BIT);
 }
 
+/*
+ * We don't care about any other part of the string except the version section.
+ * Example strings: FGA80100.RC72LA.312_T01, FGA80100.RC71LS.318_T01
+ * The bytes "5a 05 03 31 00 1a 13" and possibly more come before the version
+ * string, and there may be additional bytes after the version string such as
+ * "75 00 74 00 65 00" or a postfix such as "_T01"
+ */
+static int mcu_parse_version_string(const u8 *response, size_t response_size)
+{
+	const u8 *end = response + response_size;
+	const u8 *p = response;
+	int dots, err, version;
+	char buf[4];
+
+	dots = 0;
+	while (p < end && dots < 2) {
+		if (*p++ == '.')
+			dots++;
+	}
+
+	if (dots != 2 || p >= end || (p + 3) >= end)
+		return -EINVAL;
+
+	memcpy(buf, p, 3);
+	buf[3] = '\0';
+
+	err = kstrtoint(buf, 10, &version);
+	if (err || version < 0)
+		return -EINVAL;
+
+	return version;
+}
+
+static int mcu_request_version(struct hid_device *hdev)
+{
+	u8 *response __free(kfree) = kzalloc(ROG_ALLY_REPORT_SIZE, GFP_KERNEL);
+	const u8 request[] = { 0x5a, 0x05, 0x03, 0x31, 0x00, 0x20 };
+	int ret;
+
+	if (!response)
+		return -ENOMEM;
+
+	ret = asus_kbd_set_report(hdev, request, sizeof(request));
+	if (ret < 0)
+		return ret;
+
+	ret = hid_hw_raw_request(hdev, FEATURE_REPORT_ID, response,
+				ROG_ALLY_REPORT_SIZE, HID_FEATURE_REPORT,
+				HID_REQ_GET_REPORT);
+	if (ret < 0)
+		return ret;
+
+	ret = mcu_parse_version_string(response, ROG_ALLY_REPORT_SIZE);
+	if (ret < 0) {
+		pr_err("Failed to parse MCU version: %d\n", ret);
+		print_hex_dump(KERN_ERR, "MCU: ", DUMP_PREFIX_NONE,
+			      16, 1, response, ROG_ALLY_REPORT_SIZE, false);
+	}
+
+	return ret;
+}
+
+static void validate_mcu_fw_version(struct hid_device *hdev, int idProduct)
+{
+	int min_version, version;
+
+	version = mcu_request_version(hdev);
+	if (version < 0)
+		return;
+
+	switch (idProduct) {
+	case USB_DEVICE_ID_ASUSTEK_ROG_NKEY_ALLY:
+		min_version = ROG_ALLY_MIN_MCU;
+		break;
+	case USB_DEVICE_ID_ASUSTEK_ROG_NKEY_ALLY_X:
+		min_version = ROG_ALLY_X_MIN_MCU;
+		break;
+	default:
+		min_version = 0;
+	}
+
+	if (version < min_version) {
+		hid_warn(hdev,
+			"The MCU firmware version must be %d or greater to avoid issues with suspend.\n",
+			min_version);
+	}
+}
+
 static int asus_kbd_register_leds(struct hid_device *hdev)
 {
 	struct asus_drvdata *drvdata = hid_get_drvdata(hdev);
+	struct usb_interface *intf;
+	struct usb_device *udev;
 	unsigned char kbd_func;
 	int ret;
 
@@ -560,6 +655,14 @@ static int asus_kbd_register_leds(struct hid_device *hdev)
 			if (ret < 0)
 				return ret;
 		}
+
+		if (drvdata->quirks & QUIRK_ROG_ALLY_XPAD) {
+			intf = to_usb_interface(hdev->dev.parent);
+			udev = interface_to_usbdev(intf);
+			validate_mcu_fw_version(hdev,
+				le16_to_cpu(udev->descriptor.idProduct));
+		}
+
 	} else {
 		/* Initialize keyboard */
 		ret = asus_kbd_init(hdev, FEATURE_KBD_REPORT_ID);
@@ -1280,10 +1383,10 @@ static const struct hid_device_id asus_devices[] = {
 	  QUIRK_USE_KBD_BACKLIGHT | QUIRK_ROG_NKEY_KEYBOARD },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ASUSTEK,
 	    USB_DEVICE_ID_ASUSTEK_ROG_NKEY_ALLY),
-	  QUIRK_USE_KBD_BACKLIGHT | QUIRK_ROG_NKEY_KEYBOARD },
+	  QUIRK_USE_KBD_BACKLIGHT | QUIRK_ROG_NKEY_KEYBOARD | QUIRK_ROG_ALLY_XPAD},
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ASUSTEK,
 	    USB_DEVICE_ID_ASUSTEK_ROG_NKEY_ALLY_X),
-	  QUIRK_USE_KBD_BACKLIGHT | QUIRK_ROG_NKEY_KEYBOARD },
+	  QUIRK_USE_KBD_BACKLIGHT | QUIRK_ROG_NKEY_KEYBOARD | QUIRK_ROG_ALLY_XPAD },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ASUSTEK,
 	    USB_DEVICE_ID_ASUSTEK_ROG_CLAYMORE_II_KEYBOARD),
 	  QUIRK_ROG_CLAYMORE_II_KEYBOARD },
-- 
2.48.1