static int rk3399_dmcfreq_target()

in rk3399_dmc.c [74:163]

• 62 lines of code
• 11 McCabe index (conditional complexity)

static int rk3399_dmcfreq_target(struct device *dev, unsigned long *freq,
				 u32 flags)
{
	struct rk3399_dmcfreq *dmcfreq = dev_get_drvdata(dev);
	struct dev_pm_opp *opp;
	unsigned long old_clk_rate = dmcfreq->rate;
	unsigned long target_volt, target_rate;
	struct arm_smccc_res res;
	bool odt_enable = false;
	int err;

	opp = devfreq_recommended_opp(dev, freq, flags);
	if (IS_ERR(opp))
		return PTR_ERR(opp);

	target_rate = dev_pm_opp_get_freq(opp);
	target_volt = dev_pm_opp_get_voltage(opp);
	dev_pm_opp_put(opp);

	if (dmcfreq->rate == target_rate)
		return 0;

	mutex_lock(&dmcfreq->lock);

	if (dmcfreq->regmap_pmu) {
		if (target_rate >= dmcfreq->odt_dis_freq)
			odt_enable = true;

		/*
		 * This makes a SMC call to the TF-A to set the DDR PD
		 * (power-down) timings and to enable or disable the
		 * ODT (on-die termination) resistors.
		 */
		arm_smccc_smc(ROCKCHIP_SIP_DRAM_FREQ, dmcfreq->odt_pd_arg0,
			      dmcfreq->odt_pd_arg1,
			      ROCKCHIP_SIP_CONFIG_DRAM_SET_ODT_PD,
			      odt_enable, 0, 0, 0, &res);
	}

	/*
	 * If frequency scaling from low to high, adjust voltage first.
	 * If frequency scaling from high to low, adjust frequency first.
	 */
	if (old_clk_rate < target_rate) {
		err = regulator_set_voltage(dmcfreq->vdd_center, target_volt,
					    target_volt);
		if (err) {
			dev_err(dev, "Cannot set voltage %lu uV\n",
				target_volt);
			goto out;
		}
	}

	err = clk_set_rate(dmcfreq->dmc_clk, target_rate);
	if (err) {
		dev_err(dev, "Cannot set frequency %lu (%d)\n", target_rate,
			err);
		regulator_set_voltage(dmcfreq->vdd_center, dmcfreq->volt,
				      dmcfreq->volt);
		goto out;
	}

	/*
	 * Check the dpll rate,
	 * There only two result we will get,
	 * 1. Ddr frequency scaling fail, we still get the old rate.
	 * 2. Ddr frequency scaling sucessful, we get the rate we set.
	 */
	dmcfreq->rate = clk_get_rate(dmcfreq->dmc_clk);

	/* If get the incorrect rate, set voltage to old value. */
	if (dmcfreq->rate != target_rate) {
		dev_err(dev, "Got wrong frequency, Request %lu, Current %lu\n",
			target_rate, dmcfreq->rate);
		regulator_set_voltage(dmcfreq->vdd_center, dmcfreq->volt,
				      dmcfreq->volt);
		goto out;
	} else if (old_clk_rate > target_rate)
		err = regulator_set_voltage(dmcfreq->vdd_center, target_volt,
					    target_volt);
	if (err)
		dev_err(dev, "Cannot set voltage %lu uV\n", target_volt);

	dmcfreq->rate = target_rate;
	dmcfreq->volt = target_volt;

out:
	mutex_unlock(&dmcfreq->lock);
	return err;
}