static int ti_eqep_action_read()

in ti-eqep.c [176:239]

• 49 lines of code
• 12 McCabe index (conditional complexity)

static int ti_eqep_action_read(struct counter_device *counter,
			       struct counter_count *count,
			       struct counter_synapse *synapse,
			       enum counter_synapse_action *action)
{
	struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter);
	enum counter_function function;
	u32 qdecctl;
	int err;

	err = ti_eqep_function_read(counter, count, &function);
	if (err)
		return err;

	switch (function) {
	case COUNTER_FUNCTION_QUADRATURE_X4:
		/* In quadrature mode, the rising and falling edge of both
		 * QEPA and QEPB trigger QCLK.
		 */
		*action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
		return 0;
	case COUNTER_FUNCTION_PULSE_DIRECTION:
		/* In direction-count mode only rising edge of QEPA is counted
		 * and QEPB gives direction.
		 */
		switch (synapse->signal->id) {
		case TI_EQEP_SIGNAL_QEPA:
			*action = COUNTER_SYNAPSE_ACTION_RISING_EDGE;
			return 0;
		case TI_EQEP_SIGNAL_QEPB:
			*action = COUNTER_SYNAPSE_ACTION_NONE;
			return 0;
		default:
			/* should never reach this path */
			return -EINVAL;
		}
	case COUNTER_FUNCTION_INCREASE:
	case COUNTER_FUNCTION_DECREASE:
		/* In up/down-count modes only QEPA is counted and QEPB is not
		 * used.
		 */
		switch (synapse->signal->id) {
		case TI_EQEP_SIGNAL_QEPA:
			err = regmap_read(priv->regmap16, QDECCTL, &qdecctl);
			if (err)
				return err;

			if (qdecctl & QDECCTL_XCR)
				*action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
			else
				*action = COUNTER_SYNAPSE_ACTION_RISING_EDGE;
			return 0;
		case TI_EQEP_SIGNAL_QEPB:
			*action = COUNTER_SYNAPSE_ACTION_NONE;
			return 0;
		default:
			/* should never reach this path */
			return -EINVAL;
		}
	default:
		/* should never reach this path */
		return -EINVAL;
	}
}