From: Louis Yung-Chieh Lo yjlou@chromium.org
The BIOS leaves the keyboard enabled during boot time so that any keystroke would interfere kernel driver initialization.
Add a way to disable the keyboard to make sure no scancode will be generated during the boot time. Note that the keyboard will be re-enabled again after the kernel driver is up.
This code can be called from the board functions. Signed-off-by: Louis Yung-Chieh Lo yjlou@chromium.org
Signed-off-by: Louis Yung-Chieh Lo yjlou@chromium.org Signed-off-by: Simon Glass sjg@chromium.org --- drivers/input/i8042.c | 38 ++++++++++++++++++++++++++++++++++++++ include/i8042.h | 13 +++++++++++++ 2 files changed, 51 insertions(+), 0 deletions(-)
diff --git a/drivers/input/i8042.c b/drivers/input/i8042.c index cae2d0a..6b51eb5 100644 --- a/drivers/input/i8042.c +++ b/drivers/input/i8042.c @@ -331,6 +331,44 @@ int __board_i8042_skip(void) } int board_i8042_skip(void) __attribute__((weak, alias("__board_i8042_skip")));
+void i8042_flush(void) +{ + int timeout; + + /* + * The delay is to give the keyboard controller some time to fill the + * next byte. + */ + while (1) { + timeout = 100; /* wait for no longer than 100us */ + while (timeout > 0 && !(in8(I8042_STATUS_REG) & 0x01)) { + udelay(1); + timeout--; + } + + /* Try to pull next byte if not timeout. */ + if (in8(I8042_STATUS_REG) & 0x01) + in8(I8042_DATA_REG); + else + break; + } +} + +int i8042_disable(void) +{ + if (kbd_input_empty() == 0) + return -1; + + /* Disable keyboard */ + out8(I8042_COMMAND_REG, 0xad); + + if (kbd_input_empty() == 0) + return -1; + + return 0; +} + + /******************************************************************************* * * i8042_kbd_init - reset keyboard and init state flags diff --git a/include/i8042.h b/include/i8042.h index 1395289..c3e4e02 100644 --- a/include/i8042.h +++ b/include/i8042.h @@ -69,6 +69,19 @@
/* exports */
+/** + * Flush all buffer from keyboard controller to host. + */ +void i8042_flush(void); + +/** + * Disables the keyboard so that key strokes no longer generate scancodes to + * the host. + * + * @return 0 if ok, -1 if keyboard input was found while disabling + */ +int i8042_disable(void); + int i8042_kbd_init(void); int i8042_tstc(void); int i8042_getc(void);