Input: melfas_mip4 - add hw_version sysfs attribute

Add hw_version sysfs attribute for retrieving hardware information
from firmware.

Signed-off-by: Sangwon Jee <jeesw@melfas.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
diff --git a/drivers/input/touchscreen/melfas_mip4.c b/drivers/input/touchscreen/melfas_mip4.c
index 89272973..fb5fb91 100644
--- a/drivers/input/touchscreen/melfas_mip4.c
+++ b/drivers/input/touchscreen/melfas_mip4.c
@@ -1310,8 +1310,34 @@
 
 static DEVICE_ATTR(fw_version, S_IRUGO, mip4_sysfs_read_fw_version, NULL);
 
+static ssize_t mip4_sysfs_read_hw_version(struct device *dev,
+					  struct device_attribute *attr,
+					  char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct mip4_ts *ts = i2c_get_clientdata(client);
+	size_t count;
+
+	/* Take lock to prevent racing with firmware update */
+	mutex_lock(&ts->input->mutex);
+
+	/*
+	 * product_name shows the name or version of the hardware
+	 * paired with current firmware in the chip.
+	 */
+	count = snprintf(buf, PAGE_SIZE, "%.*s\n",
+		(int)sizeof(ts->product_name), ts->product_name);
+
+	mutex_unlock(&ts->input->mutex);
+
+	return count;
+}
+
+static DEVICE_ATTR(hw_version, S_IRUGO, mip4_sysfs_read_hw_version, NULL);
+
 static struct attribute *mip4_attrs[] = {
 	&dev_attr_fw_version.attr,
+	&dev_attr_hw_version.attr,
 	&dev_attr_update_fw.attr,
 	NULL,
 };
@@ -1512,6 +1538,6 @@
 module_i2c_driver(mip4_driver);
 
 MODULE_DESCRIPTION("MELFAS MIP4 Touchscreen");
-MODULE_VERSION("2016.03.03");
+MODULE_VERSION("2016.03.12");
 MODULE_AUTHOR("Sangwon Jee <jeesw@melfas.com>");
 MODULE_LICENSE("GPL");