Commit a1f0019c authored by Bjorn Andersson's avatar Bjorn Andersson Committed by Stephen Boyd
Browse files

clk: qcom: clk-alpha-pll: Don't reconfigure running Trion 



In the event that the bootloader has configured the Trion PLL as source
for the display clocks, e.g. for the continuous splashscreen, then there
will also be RCGs that are clocked by this instance.

Reconfiguring, and in particular disabling the output of, the PLL will
cause issues for these downstream RCGs and has been shown to prevent
them from being re-parented.

Follow downstream and skip configuration if it's determined that the PLL
is already running.

Fixes: 59128c20 ("clk: qcom: clk-alpha-pll: Add support for controlling Lucid PLLs")
Signed-off-by: default avatarBjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: default avatarRobert Foss <robert.foss@linaro.org>
Reviewed-by: default avatarVinod Koul <vkoul@kernel.org>
Link: https://lore.kernel.org/r/20211123162508.153711-1-bjorn.andersson@linaro.org


Signed-off-by: default avatarStephen Boyd <sboyd@kernel.org>
parent 9a61f813

drivers/clk/qcom/clk-alpha-pll.c

+9 −0
Original line number Diff line number Diff line
@@ -1429,6 +1429,15 @@ EXPORT_SYMBOL_GPL(clk_alpha_pll_postdiv_fabia_ops); 
void clk_trion_pll_configure(struct clk_alpha_pll *pll, struct regmap *regmap,

			     const struct alpha_pll_config *config)

{

	/*

	 * If the bootloader left the PLL enabled it's likely that there are

	 * RCGs that will lock up if we disable the PLL below.

	 */

	if (trion_pll_is_enabled(pll, regmap)) {

		pr_debug("Trion PLL is already enabled, skipping configuration\n");

		return;

	}



	clk_alpha_pll_write_config(regmap, PLL_L_VAL(pll), config->l);

	regmap_write(regmap, PLL_CAL_L_VAL(pll), TRION_PLL_CAL_VAL);

	clk_alpha_pll_write_config(regmap, PLL_ALPHA_VAL(pll), config->alpha);