[PATCH] identify firmware version

[Rafi Rubin <rafi@seas.upenn.edu>]

This adds firmware version polling to the end of probe and reports the
version both in the raw form and proccessed to match the formatting used
by N-Trig.

Signed-off-by: Rafi Rubin <rafi@seas.upenn.edu>
---
 drivers/hid/hid-ntrig.c |   56 +++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 56 insertions(+), 0 deletions(-)

diff --git a/drivers/hid/hid-ntrig.c b/drivers/hid/hid-ntrig.c
index 43e95de..3472b3b 100644
--- a/drivers/hid/hid-ntrig.c
+++ b/drivers/hid/hid-ntrig.c
@@ -90,6 +90,26 @@ struct ntrig_data {
 };
 
 
+/*
+ * This function converts the 4 byte raw firmware code into
+ * a string containing 5 comma separated numbers.
+ */
+static int ntrig_version_string(unsigned char *raw, char *buf)
+{
+	__u8 a =  (raw[1] & 0x0e) >> 1;
+	__u8 b =  (raw[0] & 0x3c) >> 2;
+	__u8 c = ((raw[0] & 0x03) << 3) | ((raw[3] & 0xe0) >> 5);
+	__u8 d = ((raw[3] & 0x07) << 3) | ((raw[2] & 0xe0) >> 5);
+	__u8 e =   raw[2] & 0x07;
+
+	/*
+	 * As yet unmapped bits:
+	 * 0b11000000 0b11110001 0b00011000 0b00011000
+	 */
+
+	return sprintf(buf, "%u.%u.%u.%u.%u", a, b, c, d, e);
+}
+
 static ssize_t show_phys_width(struct device *dev,
 			       struct device_attribute *attr,
 			       char *buf)
@@ -776,6 +796,9 @@ static int ntrig_probe(struct hid_device *hdev, const struct hid_device_id *id)
 	struct hid_input *hidinput;
 	struct input_dev *input;
 	struct hid_report *report;
+	unsigned char *data;
+	struct usb_device *usb_dev = hid_to_usb_dev(hdev);
+	char *buf;
 
 	if (id->driver_data)
 		hdev->quirks |= HID_QUIRK_MULTI_INPUT;
@@ -848,10 +871,43 @@ static int ntrig_probe(struct hid_device *hdev, const struct hid_device_id *id)
 	if (report)
 		usbhid_submit_report(hdev, report, USB_DIR_OUT);
 
+	data = kmalloc(8, GFP_KERNEL);
+	if (!data) {
+		ret = -ENOMEM;
+		goto err_free;
+	}
+
+	ret = usb_control_msg(usb_dev, usb_rcvctrlpipe(usb_dev, 0),
+			      USB_REQ_CLEAR_FEATURE,
+			      USB_TYPE_CLASS | USB_RECIP_INTERFACE |
+			      USB_DIR_IN,
+			      0x30c, 1, data, 8,
+			      USB_CTRL_SET_TIMEOUT);
+
+	if (ret == 8) {
+		buf = kmalloc(20, GFP_KERNEL);
+		if (!buf) {
+			ret = -ENOMEM;
+			goto err_free_data;
+		}
+
+		ret = ntrig_version_string(&data[2], buf);
+
+		dev_info(&hdev->dev,
+			 "Firmware version: %s (%02x%02x %02x%02x)\n",
+			 buf, data[2], data[3], data[4], data[5]);
+
+		kfree(buff);
+	}
+
 	ret = sysfs_create_group(&hdev->dev.kobj,
 			&ntrig_attribute_group);
 
+	kfree(data);
+
 	return 0;
+err_free_data:
+	kfree(data);
 err_free:
 	kfree(nd);
 	return ret;
-- 
1.7.1