HID: add sysfs speed attribute for wacom bluetooth tablet
The attribute allows to change reporting speed of tablet from userspace through
sysfs file. The attribute is RW, valid values: 0 is low speed, 1 is high speed.
High speed is the default setting. Using low speed is a workaround if you
experience lag when using the tablet.
Signed-off-by: Przemo Firszt <przemo@firszt.eu>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/hid-wacom.c b/drivers/hid/hid-wacom.c
index f9d4939..97ef626 100644
--- a/drivers/hid/hid-wacom.c
+++ b/drivers/hid/hid-wacom.c
@@ -30,6 +30,7 @@
struct wacom_data {
__u16 tool;
unsigned char butstate;
+ unsigned char high_speed;
#ifdef CONFIG_HID_WACOM_POWER_SUPPLY
int battery_capacity;
struct power_supply battery;
@@ -105,6 +106,7 @@
static void wacom_poke(struct hid_device *hdev, u8 speed)
{
+ struct wacom_data *wdata = hid_get_drvdata(hdev);
int limit, ret;
char rep_data[2];
@@ -128,8 +130,10 @@
HID_FEATURE_REPORT);
} while (ret < 0 && limit-- > 0);
- if (ret >= 0)
+ if (ret >= 0) {
+ wdata->high_speed = speed;
return;
+ }
}
/*
@@ -141,6 +145,35 @@
return;
}
+static ssize_t wacom_show_speed(struct device *dev,
+ struct device_attribute
+ *attr, char *buf)
+{
+ struct wacom_data *wdata = dev_get_drvdata(dev);
+
+ return snprintf(buf, PAGE_SIZE, "%i\n", wdata->high_speed);
+}
+
+static ssize_t wacom_store_speed(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct hid_device *hdev = container_of(dev, struct hid_device, dev);
+ int new_speed;
+
+ if (sscanf(buf, "%1d", &new_speed ) != 1)
+ return -EINVAL;
+
+ if (new_speed == 0 || new_speed == 1) {
+ wacom_poke(hdev, new_speed);
+ return strnlen(buf, PAGE_SIZE);
+ } else
+ return -EINVAL;
+}
+
+static DEVICE_ATTR(speed, S_IRUGO | S_IWUGO,
+ wacom_show_speed, wacom_store_speed);
+
static int wacom_raw_event(struct hid_device *hdev, struct hid_report *report,
u8 *raw_data, int size)
{
@@ -297,6 +330,11 @@
goto err_free;
}
+ ret = device_create_file(&hdev->dev, &dev_attr_speed);
+ if (ret)
+ dev_warn(&hdev->dev,
+ "can't create sysfs speed attribute err: %d\n", ret);
+
/* Set Wacom mode 2 with high reporting speed */
wacom_poke(hdev, 1);