| Message ID | 20241105130322.213623-8-markus.burri@mt.com |
|---|---|
| State | New |
| Headers | show |
| Series | Input: matrix-keypad: Various performance improvements | expand |
On Tue, Nov 05, 2024 at 02:03:22PM +0100, Markus Burri wrote: > For a setup where the matrix keypad is connected over a slow interface > (e.g. a gpio-expansion over i2c), the scan can take a longer time to read. > > Interrupts need to be disabled during scan. And therefore changes in this > period are not detected. > To improve this situation, scan the matrix again if the row state changed > during interrupts disabled. And what if the state changes yet again during the 2nd scan attempt? > > Signed-off-by: Markus Burri <markus.burri@mt.com> > --- > drivers/input/keyboard/matrix_keypad.c | 17 +++++++++++++++++ > 1 file changed, 17 insertions(+) > > diff --git a/drivers/input/keyboard/matrix_keypad.c b/drivers/input/keyboard/matrix_keypad.c > index 46873b8..93c8404 100644 > --- a/drivers/input/keyboard/matrix_keypad.c > +++ b/drivers/input/keyboard/matrix_keypad.c > @@ -126,6 +126,10 @@ static void matrix_keypad_scan(struct work_struct *work) > const unsigned short *keycodes = input_dev->keycode; > uint32_t new_state[MATRIX_MAX_COLS]; > int row, col, code; > + u32 init_row_state, new_row_state; > + > + /* read initial row state to detect changes between scan */ > + init_row_state = read_row_state(keypad); > > /* de-activate all columns for scanning */ > activate_all_cols(keypad, false); > @@ -174,6 +178,19 @@ static void matrix_keypad_scan(struct work_struct *work) > keypad->scan_pending = false; > enable_row_irqs(keypad); > spin_unlock_irq(&keypad->lock); > + > + /* read new row state and detect if value has changed */ > + new_row_state = read_row_state(keypad); > + if (init_row_state != new_row_state) { > + spin_lock_irq(&keypad->lock); > + if (likely(!keypad->scan_pending && !keypad->stopped)) { > + disable_row_irqs(keypad); > + keypad->scan_pending = true; > + schedule_delayed_work(&keypad->work, > + msecs_to_jiffies(keypad->debounce_ms)); > + } > + spin_unlock_irq(&keypad->lock); > + } > } > > static irqreturn_t matrix_keypad_interrupt(int irq, void *id) > -- > 2.39.5 >
diff --git a/drivers/input/keyboard/matrix_keypad.c b/drivers/input/keyboard/matrix_keypad.c index 46873b8..93c8404 100644 --- a/drivers/input/keyboard/matrix_keypad.c +++ b/drivers/input/keyboard/matrix_keypad.c @@ -126,6 +126,10 @@ static void matrix_keypad_scan(struct work_struct *work) const unsigned short *keycodes = input_dev->keycode; uint32_t new_state[MATRIX_MAX_COLS]; int row, col, code; + u32 init_row_state, new_row_state; + + /* read initial row state to detect changes between scan */ + init_row_state = read_row_state(keypad); /* de-activate all columns for scanning */ activate_all_cols(keypad, false); @@ -174,6 +178,19 @@ static void matrix_keypad_scan(struct work_struct *work) keypad->scan_pending = false; enable_row_irqs(keypad); spin_unlock_irq(&keypad->lock); + + /* read new row state and detect if value has changed */ + new_row_state = read_row_state(keypad); + if (init_row_state != new_row_state) { + spin_lock_irq(&keypad->lock); + if (likely(!keypad->scan_pending && !keypad->stopped)) { + disable_row_irqs(keypad); + keypad->scan_pending = true; + schedule_delayed_work(&keypad->work, + msecs_to_jiffies(keypad->debounce_ms)); + } + spin_unlock_irq(&keypad->lock); + } } static irqreturn_t matrix_keypad_interrupt(int irq, void *id)
For a setup where the matrix keypad is connected over a slow interface (e.g. a gpio-expansion over i2c), the scan can take a longer time to read. Interrupts need to be disabled during scan. And therefore changes in this period are not detected. To improve this situation, scan the matrix again if the row state changed during interrupts disabled. Signed-off-by: Markus Burri <markus.burri@mt.com> --- drivers/input/keyboard/matrix_keypad.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+)