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HID: wiimote: add "bboard_calib" attribute

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Balance-Boards provide 3 16bit calibration values for each of the 4
sensors. We provide these now as 192bit value via a new "bboard_calib"
sysfs attribute.
We also re-read the calibration data from the device whenever user-space
attempts to read this file. On normal Nintendo boards, this always
produces the same results, however, on some 3rd party devices these values
change until the device is fully initialized. As I have currently no idea
how long to wait until it's ready (sometimes takes up to 10s?) we provide
a simple workaround for users by reading this file.

If we, at some point, figure out how it works, we can implement it in the
kernel and provide offline data via "bboard_calib". This won't break
user-space then.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This commit is contained in:
David Herrmann 2013-05-05 23:13:05 +02:00 committed by Jiri Kosina
parent c7da08677d
commit 8b1fded7a3
2 changed files with 82 additions and 1 deletions
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15
Documentation/ABI/testing/sysfs-driver-hid-wiimote
View File

@ -42,3 +42,18 @@ Description: While a device is initialized by the wiimote driver, we perform
gen10: First Wii Remote generation
gen20: Second Wii Remote Plus generation (builtin MP)
balanceboard: Wii Balance Board
What: /sys/bus/hid/drivers/wiimote/<dev>/bboard_calib
Date: May 2013
KernelVersion: 3.11
Contact: David Herrmann <dh.herrmann@gmail.com>
Description: This attribute is only provided if the device was detected as a
balance board. It provides a single line with 3 calibration
values for all 4 sensors. The values are separated by colons and
are each 2 bytes long (encoded as 4 digit hexadecimal value).
First, 0kg values for all 4 sensors are written, followed by the
17kg values for all 4 sensors and last the 34kg values for all 4
sensors.
Calibration data is already applied by the kernel to all input
values but may be used by user-space to perform other
transformations.

68
drivers/hid/hid-wiimote-modules.c
View File

@ -1380,6 +1380,60 @@ static void wiimod_bboard_close(struct input_dev *dev)
spin_unlock_irqrestore(&wdata->state.lock, flags);
}
static ssize_t wiimod_bboard_calib_show(struct device *dev,
struct device_attribute *attr,
char *out)
{
struct wiimote_data *wdata = dev_to_wii(dev);
int i, j, ret;
__u16 val;
__u8 buf[24], offs;
ret = wiimote_cmd_acquire(wdata);
if (ret)
return ret;
ret = wiimote_cmd_read(wdata, 0xa40024, buf, 12);
if (ret != 12) {
wiimote_cmd_release(wdata);
return ret < 0 ? ret : -EIO;
}
ret = wiimote_cmd_read(wdata, 0xa40024 + 12, buf + 12, 12);
if (ret != 12) {
wiimote_cmd_release(wdata);
return ret < 0 ? ret : -EIO;
}
wiimote_cmd_release(wdata);
spin_lock_irq(&wdata->state.lock);
offs = 0;
for (i = 0; i < 3; ++i) {
for (j = 0; j < 4; ++j) {
wdata->state.calib_bboard[j][i] = buf[offs];
wdata->state.calib_bboard[j][i] <<= 8;
wdata->state.calib_bboard[j][i] |= buf[offs + 1];
offs += 2;
}
}
spin_unlock_irq(&wdata->state.lock);
ret = 0;
for (i = 0; i < 3; ++i) {
for (j = 0; j < 4; ++j) {
val = wdata->state.calib_bboard[j][i];
if (i == 2 && j == 3)
ret += sprintf(&out[ret], "%04x\n", val);
else
ret += sprintf(&out[ret], "%04x:", val);
}
}
return ret;
}
static DEVICE_ATTR(bboard_calib, S_IRUGO, wiimod_bboard_calib_show, NULL);
static int wiimod_bboard_probe(const struct wiimod_ops *ops,
struct wiimote_data *wdata)
{
@ -1415,6 +1469,13 @@ static int wiimod_bboard_probe(const struct wiimod_ops *ops,
if (!wdata->extension.input)
return -ENOMEM;
ret = device_create_file(&wdata->hdev->dev,
&dev_attr_bboard_calib);
if (ret) {
hid_err(wdata->hdev, "cannot create sysfs attribute\n");
goto err_free;
}
input_set_drvdata(wdata->extension.input, wdata);
wdata->extension.input->open = wiimod_bboard_open;
wdata->extension.input->close = wiimod_bboard_close;
@ -1444,10 +1505,13 @@ static int wiimod_bboard_probe(const struct wiimod_ops *ops,
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_bboard_calib);
err_free:
input_free_device(wdata->extension.input);
wdata->extension.input = NULL;
@ -1462,6 +1526,8 @@ static void wiimod_bboard_remove(const struct wiimod_ops *ops,
input_unregister_device(wdata->extension.input);
wdata->extension.input = NULL;
device_remove_file(&wdata->hdev->dev,
&dev_attr_bboard_calib);
}
static const struct wiimod_ops wiimod_bboard = {