static int _idtcm_adjphase()

in ptp_clockmatrix.c [1709:1747]

• 27 lines of code
• 6 McCabe index (conditional complexity)

static int _idtcm_adjphase(struct idtcm_channel *channel, s32 delta_ns)
{
	struct idtcm *idtcm = channel->idtcm;
	int err;
	u8 i;
	u8 buf[4] = {0};
	s32 phase_50ps;
	s64 offset_ps;

	if (channel->mode != PTP_PLL_MODE_WRITE_PHASE) {
		err = channel->configure_write_phase(channel);
		if (err)
			return err;
	}

	offset_ps = (s64)delta_ns * 1000;

	/*
	 * Check for 32-bit signed max * 50:
	 *
	 * 0x7fffffff * 50 =  2147483647 * 50 = 107374182350
	 */
	if (offset_ps > MAX_ABS_WRITE_PHASE_PICOSECONDS)
		offset_ps = MAX_ABS_WRITE_PHASE_PICOSECONDS;
	else if (offset_ps < -MAX_ABS_WRITE_PHASE_PICOSECONDS)
		offset_ps = -MAX_ABS_WRITE_PHASE_PICOSECONDS;

	phase_50ps = div_s64(offset_ps, 50);

	for (i = 0; i < 4; i++) {
		buf[i] = phase_50ps & 0xff;
		phase_50ps >>= 8;
	}

	err = idtcm_write(idtcm, channel->dpll_phase, DPLL_WR_PHASE,
			  buf, sizeof(buf));

	return err;
}