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Add USH HID keyboard debouncing

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git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3265 42af7a65-404d-4744-a932-0658087f49c3
This commit is contained in:
patacongo 2011-01-20 00:46:56 +00:00
parent 78d6af1190
commit c38d1c1ec9
1 changed files with 32 additions and 2 deletions
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34
drivers/usbhost/usbhost_hidkbd.c
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@ -696,6 +696,9 @@ static int usbhost_kbdpoll(int argc, char *argv[])
{
FAR struct usbhost_state_s *priv;
FAR struct usb_ctrlreq_s *ctrlreq;
#ifndef CONFIG_HIDKBD_NODEBOUNCE
uint8_t lastkey[6] = {0, 0, 0, 0, 0, 0};
#endif
#if defined(CONFIG_DEBUG_USB) && defined(CONFIG_DEBUG_VERBOSE)
unsigned int npolls = 0;
#endif
@ -793,9 +796,29 @@ static int usbhost_kbdpoll(int argc, char *argv[])
for (i = 0; i < 6; i++)
{
/* Is this key pressed? */
/* Is this key pressed? But not pressed last time?
* HID spec: "The order of keycodes in array fields has no
* significance. Order determination is done by the host
* software comparing the contents of the previous report to
* the current report. If two or more keys are reported in
* one report, their order is indeterminate. Keyboards may
* buffer events that would have otherwise resulted in
* multiple event in a single report.
*
* "'Repeat Rate' and 'Delay Before First Repeat' are
* implemented by the host and not in the keyboard (this
* means the BIOS in legacy mode). The host may use the
* device report rate and the number of reports to determine
* how long a key is being held down. Alternatively, the host
* may use its own clock or the idle request for the timing
* of these features."
*/
if (rpt->key[i] != USBHID_KBDUSE_NONE)
if (rpt->key[i] != USBHID_KBDUSE_NONE
#ifndef CONFIG_HIDKBD_NODEBOUNCE
&& rpt->key[i] != lastkey[i]
#endif
)
{
/* Yes.. Add it to the buffer. */
@ -850,6 +873,13 @@ static int usbhost_kbdpoll(int argc, char *argv[])
}
}
}
/* Save the scancode (or lack thereof) for key debouncing on
* next keyboard report.
*/
#ifndef CONFIG_HIDKBD_NODEBOUNCE
lastkey[i] = rpt->key[i];
#endif
}
/* Did we just transition from no data available to data available? */