HID: wiimote: add pro-controller analog stick calibration

The analog sticks of the pro-controller might report slightly off values.
To guarantee a uniform setup, we now calibrate analog-stick values during
pro-controller setup.

Unfortunately, the pro-controller fails during normal EEPROM reads and I
couldn't figure out whether there are any calibration values stored on the
device. Therefore, we now use the first values reported by the device (iff
they are not _way_ off, which would indicate movement) to initialize the
calibration values. To allow users to change this calibration data, we
provide a pro_calib sysfs attribute.

We also change the "flat" values so user-space correctly smoothes our
data. It makes slightly off zero-positions less visible while still
guaranteeing highly precise movement reports. Note that the pro controller
reports zero-positions in a quite huge range (at least: -100 to +100).

Reported-by: Rafael Brune <mail@rbrune.de>
Tested-by: Rafael Brune <mail@rbrune.de>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --git a/Documentation/ABI/testing/sysfs-driver-hid-wiimote b/Documentation/ABI/testing/sysfs-driver-hid-wiimote
index ed5dd56..39dfa5c 100644 (file)
--- a/Documentation/ABI/testing/sysfs-driver-hid-wiimote
+++ b/Documentation/ABI/testing/sysfs-driver-hid-wiimote
@@ -57,3 +57,21 @@ Description: This attribute is only provided if the device was detected as a
                Calibration data is already applied by the kernel to all input
                values but may be used by user-space to perform other
                transformations.
+
+What:          /sys/bus/hid/drivers/wiimote/<dev>/pro_calib
+Date:          October 2013
+KernelVersion: 3.13
+Contact:       David Herrmann <dh.herrmann@gmail.com>
+Description:   This attribute is only provided if the device was detected as a
+               pro-controller. It provides a single line with 4 calibration
+               values for all 4 analog sticks. Format is: "x1:y1 x2:y2". Data
+               is prefixed with a +/-. Each value is a signed 16bit number.
+               Data is encoded as decimal numbers and specifies the offsets of
+               the analog sticks of the pro-controller.
+               Calibration data is already applied by the kernel to all input
+               values but may be used by user-space to perform other
+               transformations.
+               Calibration data is detected by the kernel during device setup.
+               You can write "scan\n" into this file to re-trigger calibration.
+               You can also write data directly in the form "x1:y1 x2:y2" to
+               set the calibration values manually.

diff --git a/drivers/hid/hid-wiimote-modules.c b/drivers/hid/hid-wiimote-modules.c
index e30567a..6b61f01 100644 (file)
--- a/drivers/hid/hid-wiimote-modules.c
+++ b/drivers/hid/hid-wiimote-modules.c
@@ -1655,10 +1655,39 @@ static void wiimod_pro_in_ext(struct wiimote_data *wdata, const __u8 *ext)
        ly = (ext[4] & 0xff) | ((ext[5] & 0x0f) << 8);
        ry = (ext[6] & 0xff) | ((ext[7] & 0x0f) << 8);
 
-       input_report_abs(wdata->extension.input, ABS_X, lx - 0x800);
-       input_report_abs(wdata->extension.input, ABS_Y, 0x800 - ly);
-       input_report_abs(wdata->extension.input, ABS_RX, rx - 0x800);
-       input_report_abs(wdata->extension.input, ABS_RY, 0x800 - ry);
+       /* zero-point offsets */
+       lx -= 0x800;
+       ly = 0x800 - ly;
+       rx -= 0x800;
+       ry = 0x800 - ry;
+
+       /* Trivial automatic calibration. We don't know any calibration data
+        * in the EEPROM so we must use the first report to calibrate the
+        * null-position of the analog sticks. Users can retrigger calibration
+        * via sysfs, or set it explicitly. If data is off more than abs(500),
+        * we skip calibration as the sticks are likely to be moved already. */
+       if (!(wdata->state.flags & WIIPROTO_FLAG_PRO_CALIB_DONE)) {
+               wdata->state.flags |= WIIPROTO_FLAG_PRO_CALIB_DONE;
+               if (abs(lx) < 500)
+                       wdata->state.calib_pro_sticks[0] = -lx;
+               if (abs(ly) < 500)
+                       wdata->state.calib_pro_sticks[1] = -ly;
+               if (abs(rx) < 500)
+                       wdata->state.calib_pro_sticks[2] = -rx;
+               if (abs(ry) < 500)
+                       wdata->state.calib_pro_sticks[3] = -ry;
+       }
+
+       /* apply calibration data */
+       lx += wdata->state.calib_pro_sticks[0];
+       ly += wdata->state.calib_pro_sticks[1];
+       rx += wdata->state.calib_pro_sticks[2];
+       ry += wdata->state.calib_pro_sticks[3];
+
+       input_report_abs(wdata->extension.input, ABS_X, lx);
+       input_report_abs(wdata->extension.input, ABS_Y, ly);
+       input_report_abs(wdata->extension.input, ABS_RX, rx);
+       input_report_abs(wdata->extension.input, ABS_RY, ry);
 
        input_report_key(wdata->extension.input,
                         wiimod_pro_map[WIIMOD_PRO_KEY_RIGHT],
@@ -1766,12 +1795,70 @@ static int wiimod_pro_play(struct input_dev *dev, void *data,
        return 0;
 }
 
+static ssize_t wiimod_pro_calib_show(struct device *dev,
+                                    struct device_attribute *attr,
+                                    char *out)
+{
+       struct wiimote_data *wdata = dev_to_wii(dev);
+       int r;
+
+       r = 0;
+       r += sprintf(&out[r], "%+06hd:", wdata->state.calib_pro_sticks[0]);
+       r += sprintf(&out[r], "%+06hd ", wdata->state.calib_pro_sticks[1]);
+       r += sprintf(&out[r], "%+06hd:", wdata->state.calib_pro_sticks[2]);
+       r += sprintf(&out[r], "%+06hd\n", wdata->state.calib_pro_sticks[3]);
+
+       return r;
+}
+
+static ssize_t wiimod_pro_calib_store(struct device *dev,
+                                     struct device_attribute *attr,
+                                     const char *buf, size_t count)
+{
+       struct wiimote_data *wdata = dev_to_wii(dev);
+       int r;
+       s16 x1, y1, x2, y2;
+
+       if (!strncmp(buf, "scan\n", 5)) {
+               spin_lock_irq(&wdata->state.lock);
+               wdata->state.flags &= ~WIIPROTO_FLAG_PRO_CALIB_DONE;
+               spin_unlock_irq(&wdata->state.lock);
+       } else {
+               r = sscanf(buf, "%hd:%hd %hd:%hd", &x1, &y1, &x2, &y2);
+               if (r != 4)
+                       return -EINVAL;
+
+               spin_lock_irq(&wdata->state.lock);
+               wdata->state.flags |= WIIPROTO_FLAG_PRO_CALIB_DONE;
+               spin_unlock_irq(&wdata->state.lock);
+
+               wdata->state.calib_pro_sticks[0] = x1;
+               wdata->state.calib_pro_sticks[1] = y1;
+               wdata->state.calib_pro_sticks[2] = x2;
+               wdata->state.calib_pro_sticks[3] = y2;
+       }
+
+       return strnlen(buf, PAGE_SIZE);
+}
+
+static DEVICE_ATTR(pro_calib, S_IRUGO|S_IWUSR|S_IWGRP, wiimod_pro_calib_show,
+                  wiimod_pro_calib_store);
+
 static int wiimod_pro_probe(const struct wiimod_ops *ops,
                            struct wiimote_data *wdata)
 {
        int ret, i;
+       unsigned long flags;
 
        INIT_WORK(&wdata->rumble_worker, wiimod_rumble_worker);
+       wdata->state.calib_pro_sticks[0] = 0;
+       wdata->state.calib_pro_sticks[1] = 0;
+       wdata->state.calib_pro_sticks[2] = 0;
+       wdata->state.calib_pro_sticks[3] = 0;
+
+       spin_lock_irqsave(&wdata->state.lock, flags);
+       wdata->state.flags &= ~WIIPROTO_FLAG_PRO_CALIB_DONE;
+       spin_unlock_irqrestore(&wdata->state.lock, flags);
 
        wdata->extension.input = input_allocate_device();
        if (!wdata->extension.input)
@@ -1786,6 +1873,13 @@ static int wiimod_pro_probe(const struct wiimod_ops *ops,
                goto err_free;
        }
 
+       ret = device_create_file(&wdata->hdev->dev,
+                                &dev_attr_pro_calib);
+       if (ret) {
+               hid_err(wdata->hdev, "cannot create sysfs attribute\n");
+               goto err_free;
+       }
+
        wdata->extension.input->open = wiimod_pro_open;
        wdata->extension.input->close = wiimod_pro_close;
        wdata->extension.input->dev.parent = &wdata->hdev->dev;
@@ -1806,20 +1900,23 @@ static int wiimod_pro_probe(const struct wiimod_ops *ops,
        set_bit(ABS_RX, wdata->extension.input->absbit);
        set_bit(ABS_RY, wdata->extension.input->absbit);
        input_set_abs_params(wdata->extension.input,
-                            ABS_X, -0x800, 0x800, 2, 4);
+                            ABS_X, -0x400, 0x400, 4, 100);
        input_set_abs_params(wdata->extension.input,
-                            ABS_Y, -0x800, 0x800, 2, 4);
+                            ABS_Y, -0x400, 0x400, 4, 100);
        input_set_abs_params(wdata->extension.input,
-                            ABS_RX, -0x800, 0x800, 2, 4);
+                            ABS_RX, -0x400, 0x400, 4, 100);
        input_set_abs_params(wdata->extension.input,
-                            ABS_RY, -0x800, 0x800, 2, 4);
+                            ABS_RY, -0x400, 0x400, 4, 100);
 
        ret = input_register_device(wdata->extension.input);
        if (ret)
-               goto err_free;
+               goto err_file;
 
        return 0;
 
+err_file:
+       device_remove_file(&wdata->hdev->dev,
+                          &dev_attr_pro_calib);
 err_free:
        input_free_device(wdata->extension.input);
        wdata->extension.input = NULL;
@@ -1837,6 +1934,8 @@ static void wiimod_pro_remove(const struct wiimod_ops *ops,
        input_unregister_device(wdata->extension.input);
        wdata->extension.input = NULL;
        cancel_work_sync(&wdata->rumble_worker);
+       device_remove_file(&wdata->hdev->dev,
+                          &dev_attr_pro_calib);
 
        spin_lock_irqsave(&wdata->state.lock, flags);
        wiiproto_req_rumble(wdata, 0);

diff --git a/drivers/hid/hid-wiimote.h b/drivers/hid/hid-wiimote.h
index 75db0c4..03065f1 100644 (file)
--- a/drivers/hid/hid-wiimote.h
+++ b/drivers/hid/hid-wiimote.h
@@ -46,6 +46,7 @@
 #define WIIPROTO_FLAG_DRM_LOCKED       0x8000
 #define WIIPROTO_FLAG_BUILTIN_MP       0x010000
 #define WIIPROTO_FLAG_NO_MP            0x020000
+#define WIIPROTO_FLAG_PRO_CALIB_DONE   0x040000
 
 #define WIIPROTO_FLAGS_LEDS (WIIPROTO_FLAG_LED1 | WIIPROTO_FLAG_LED2 | \
                                        WIIPROTO_FLAG_LED3 | WIIPROTO_FLAG_LED4)
@@ -135,6 +136,7 @@ struct wiimote_state {
 
        /* calibration/cache data */
        __u16 calib_bboard[4][3];
+       __s16 calib_pro_sticks[4];
        __u8 cache_rumble;
 };