Commit b3b274bc authored by Dmitry Baryshkov's avatar Dmitry Baryshkov Committed by Bjorn Andersson
Browse files

clk: qcom: cpu-8996: simplify the cpu_clk_notifier_cb 



- Do not use the Alt PLL completely. Switch to smux when necessary to
  prevent overvolting
- Restore the parent in case the rate change aborts for some reason
- Do not duplicate resetting the parent in set_parent operation.

Reviewed-by: default avatarKonrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: default avatarDmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: default avatarBjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230113120544.59320-8-dmitry.baryshkov@linaro.org
parent 72537606

drivers/clk/qcom/clk-cpu-8996.c

+19 −11
Original line number Diff line number Diff line
@@ -506,27 +506,35 @@ static int cpu_clk_notifier_cb(struct notifier_block *nb, unsigned long event, 
{

	struct clk_cpu_8996_pmux *cpuclk = to_clk_cpu_8996_pmux_nb(nb);

	struct clk_notifier_data *cnd = data;

	int ret;



	switch (event) {

	case PRE_RATE_CHANGE:

		ret = clk_cpu_8996_pmux_set_parent(&cpuclk->clkr.hw, ALT_INDEX);

		qcom_cpu_clk_msm8996_acd_init(base);



		/*

		 * Avoid overvolting. clk_core_set_rate_nolock() walks from top

		 * to bottom, so it will change the rate of the PLL before

		 * chaging the parent of PMUX. This can result in pmux getting

		 * clocked twice the expected rate.

		 *

		 * Manually switch to PLL/2 here.

		 */

		if (cnd->new_rate < DIV_2_THRESHOLD &&

		    cnd->old_rate > DIV_2_THRESHOLD)

			clk_cpu_8996_pmux_set_parent(&cpuclk->clkr.hw, SMUX_INDEX);



		break;

	case POST_RATE_CHANGE:

		if (cnd->new_rate < DIV_2_THRESHOLD)

			ret = clk_cpu_8996_pmux_set_parent(&cpuclk->clkr.hw,

							   SMUX_INDEX);

		else

			ret = clk_cpu_8996_pmux_set_parent(&cpuclk->clkr.hw,

							   ACD_INDEX);

	case ABORT_RATE_CHANGE:

		/* Revert manual change */

		if (cnd->new_rate < DIV_2_THRESHOLD &&

		    cnd->old_rate > DIV_2_THRESHOLD)

			clk_cpu_8996_pmux_set_parent(&cpuclk->clkr.hw, ACD_INDEX);

		break;

	default:

		ret = 0;

		break;

	}



	return notifier_from_errno(ret);

	return NOTIFY_OK;

};



static int qcom_cpu_clk_msm8996_driver_probe(struct platform_device *pdev)