/* * 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); } }