/*
* imx_keypad_check_for_events is the timer handler.
*/
static void imx_keypad_check_for_events(unsigned long data)
{
struct imx_keypad *keypad = (struct imx_keypad *) data;
unsigned short matrix_volatile_state[MAX_MATRIX_KEY_COLS];
unsigned short reg_val;
bool state_changed, is_zero_matrix;
int i;
memset(matrix_volatile_state, 0, sizeof(matrix_volatile_state));
imx_keypad_scan_matrix(keypad, matrix_volatile_state);
state_changed = false;
for (i = 0; i < MAX_MATRIX_KEY_COLS; i++) {
if ((keypad->cols_en_mask & (1 << i)) == 0)
continue;
if (keypad->matrix_unstable_state[i] ^ matrix_volatile_state[i]) {
state_changed = true;
break;
}
}
/*
* If the matrix state is changed from the previous scan
* (Re)Begin the debouncing process, saving the new state in
* keypad->matrix_unstable_state.
* else
* Increase the count of number of scans with a stable state.
*/
if (state_changed) {
memcpy(keypad->matrix_unstable_state, matrix_volatile_state,
sizeof(matrix_volatile_state));
keypad->stable_count = 0;
} else
keypad->stable_count++;
/*
* If the matrix is not as stable as we want reschedule scan
* in the near future.
*/
if (keypad->stable_count < IMX_KEYPAD_SCANS_FOR_STABILITY) {
mod_timer(&keypad->check_matrix_timer,
jiffies + msecs_to_jiffies(10));
return;
}
/*
* If the matrix state is stable, fire the events and save the new
* stable state. Note, if the matrix is kept stable for longer
* (keypad->stable_count > IMX_KEYPAD_SCANS_FOR_STABILITY) all
* events have already been generated.
*/
if (keypad->stable_count == IMX_KEYPAD_SCANS_FOR_STABILITY) {
imx_keypad_fire_events(keypad, matrix_volatile_state);
memcpy(keypad->matrix_stable_state, matrix_volatile_state,
sizeof(matrix_volatile_state));
}
is_zero_matrix = true;
for (i = 0; i < MAX_MATRIX_KEY_COLS; i++) {
if (matrix_volatile_state[i] != 0) {
is_zero_matrix = false;
break;
}
}
if (is_zero_matrix) {
/*
* All keys have been released. Enable only the KDI
* interrupt for future key presses (clear the KDI
* status bit and its sync chain before that).
*/
reg_val = readw(keypad->mmio_base + KPSR);
reg_val |= KBD_STAT_KPKD | KBD_STAT_KDSC;
writew(reg_val, keypad->mmio_base + KPSR);
reg_val = readw(keypad->mmio_base + KPSR);
reg_val |= KBD_STAT_KDIE;
reg_val &= ~KBD_STAT_KRIE;
writew(reg_val, keypad->mmio_base + KPSR);
} else {
/*
* Some keys are still pressed. Schedule a rescan in
* attempt to detect multiple key presses and enable
* the KRI interrupt to react quickly to key release
* event.
*/
mod_timer(&keypad->check_matrix_timer,
jiffies + msecs_to_jiffies(60));
reg_val = readw(keypad->mmio_base + KPSR);
reg_val |= KBD_STAT_KPKR | KBD_STAT_KRSS;
writew(reg_val, keypad->mmio_base + KPSR);
reg_val = readw(keypad->mmio_base + KPSR);
reg_val |= KBD_STAT_KRIE;
reg_val &= ~KBD_STAT_KDIE;
writew(reg_val, keypad->mmio_base + KPSR);
}
}
static void imx_keypad_check_for_events(unsigned long data)
{
struct imx_keypad *keypad = (struct imx_keypad *) data;
unsigned short matrix_volatile_state[MAX_MATRIX_KEY_COLS];
unsigned short reg_val;
bool state_changed, is_zero_matrix;
int i;
memset(matrix_volatile_state, 0, sizeof(matrix_volatile_state));
imx_keypad_scan_matrix(keypad, matrix_volatile_state);
state_changed = false;
for (i = 0; i < MAX_MATRIX_KEY_COLS; i++) {
if ((keypad->cols_en_mask & (1 << i)) == 0)
continue;
if (keypad->matrix_unstable_state[i] ^ matrix_volatile_state[i]) {
state_changed = true;
break;
}
}
if (state_changed) {
memcpy(keypad->matrix_unstable_state, matrix_volatile_state,
sizeof(matrix_volatile_state));
keypad->stable_count = 0;
} else
keypad->stable_count++;
if (keypad->stable_count < IMX_KEYPAD_SCANS_FOR_STABILITY) {
mod_timer(&keypad->check_matrix_timer,
jiffies + msecs_to_jiffies(10));
return;
}
if (keypad->stable_count == IMX_KEYPAD_SCANS_FOR_STABILITY) {
imx_keypad_fire_events(keypad, matrix_volatile_state);
memcpy(keypad->matrix_stable_state, matrix_volatile_state,
sizeof(matrix_volatile_state));
}
is_zero_matrix = true;
for (i = 0; i < MAX_MATRIX_KEY_COLS; i++) {
if (matrix_volatile_state[i] != 0) {
is_zero_matrix = false;
break;
}
}
if (is_zero_matrix) {
reg_val = readw(keypad->mmio_base + KPSR);
reg_val |= KBD_STAT_KPKD | KBD_STAT_KDSC;
writew(reg_val, keypad->mmio_base + KPSR);
reg_val = readw(keypad->mmio_base + KPSR);
reg_val |= KBD_STAT_KDIE;
reg_val &= ~KBD_STAT_KRIE;
writew(reg_val, keypad->mmio_base + KPSR);
} else {
mod_timer(&keypad->check_matrix_timer,
jiffies + msecs_to_jiffies(60));
reg_val = readw(keypad->mmio_base + KPSR);
reg_val |= KBD_STAT_KPKR | KBD_STAT_KRSS;
writew(reg_val, keypad->mmio_base + KPSR);
reg_val = readw(keypad->mmio_base + KPSR);
reg_val |= KBD_STAT_KRIE;
reg_val &= ~KBD_STAT_KDIE;
writew(reg_val, keypad->mmio_base + KPSR);
}
}