diff options
Diffstat (limited to 'drivers/media/cec/core/cec-pin.c')
| -rw-r--r-- | drivers/media/cec/core/cec-pin.c | 31 |
1 files changed, 30 insertions, 1 deletions
diff --git a/drivers/media/cec/core/cec-pin.c b/drivers/media/cec/core/cec-pin.c index 59ac12113f3a..4d7155281daa 100644 --- a/drivers/media/cec/core/cec-pin.c +++ b/drivers/media/cec/core/cec-pin.c @@ -142,15 +142,42 @@ static bool cec_pin_read(struct cec_pin *pin) return v; } +static void cec_pin_insert_glitch(struct cec_pin *pin, bool rising_edge) +{ + /* + * Insert a short glitch after the falling or rising edge to + * simulate reflections on the CEC line. This can be used to + * test deglitch filters, which should be present in CEC devices + * to deal with noise on the line. + */ + if (!pin->tx_glitch_high_usecs || !pin->tx_glitch_low_usecs) + return; + if (rising_edge) { + udelay(pin->tx_glitch_high_usecs); + call_void_pin_op(pin, low); + udelay(pin->tx_glitch_low_usecs); + call_void_pin_op(pin, high); + } else { + udelay(pin->tx_glitch_low_usecs); + call_void_pin_op(pin, high); + udelay(pin->tx_glitch_high_usecs); + call_void_pin_op(pin, low); + } +} + static void cec_pin_low(struct cec_pin *pin) { call_void_pin_op(pin, low); + if (pin->tx_glitch_falling_edge && pin->adap->cec_pin_is_high) + cec_pin_insert_glitch(pin, false); cec_pin_update(pin, false, false); } static bool cec_pin_high(struct cec_pin *pin) { call_void_pin_op(pin, high); + if (pin->tx_glitch_rising_edge && !pin->adap->cec_pin_is_high) + cec_pin_insert_glitch(pin, true); return cec_pin_read(pin); } @@ -770,7 +797,7 @@ static void cec_pin_rx_states(struct cec_pin *pin, ktime_t ts) * Go to low drive state when the total bit time is * too short. */ - if (delta < CEC_TIM_DATA_BIT_TOTAL_MIN) { + if (delta < CEC_TIM_DATA_BIT_TOTAL_MIN && !pin->rx_no_low_drive) { if (!pin->rx_data_bit_too_short_cnt++) { pin->rx_data_bit_too_short_ts = ktime_to_ns(pin->ts); pin->rx_data_bit_too_short_delta = delta; @@ -1350,6 +1377,8 @@ struct cec_adapter *cec_pin_allocate_adapter(const struct cec_pin_ops *pin_ops, init_waitqueue_head(&pin->kthread_waitq); pin->tx_custom_low_usecs = CEC_TIM_CUSTOM_DEFAULT; pin->tx_custom_high_usecs = CEC_TIM_CUSTOM_DEFAULT; + pin->tx_glitch_low_usecs = CEC_TIM_GLITCH_DEFAULT; + pin->tx_glitch_high_usecs = CEC_TIM_GLITCH_DEFAULT; adap = cec_allocate_adapter(&cec_pin_adap_ops, priv, name, caps | CEC_CAP_MONITOR_ALL | CEC_CAP_MONITOR_PIN, |