clk: imx8m: fix clock tree update of TF-A managed clocks

On the i.MX8M*, the TF-A exposes a SiP (Silicon Provider) service
for DDR frequency scaling. The imx8m-ddrc-devfreq driver calls the
SiP and then does clk_set_parent on the DDR muxes to synchronize
the clock tree.

Since 936c383673b9 ("clk: imx: fix composite peripheral flags"),
these TF-A managed muxes have SET_PARENT_GATE set, which results
in imx8m-ddrc-devfreq's clk_set_parent after SiP failing with -EBUSY:

	echo 25000000 > userspace/set_freq
	imx8m-ddrc-devfreq 3d400000.memory-controller: failed to set
		dram_apb parent: -16

Fix this by adding a new i.MX composite flag for firmware managed
clocks, which clears SET_PARENT_GATE.

This is safe to do, because updating the Linux clock tree to reflect
reality will always be glitch-free.

Fixes: 936c383673b9 ("clk: imx: fix composite peripheral flags")
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Reviewed-by: Abel Vesa <abel.vesa@nxp.com>
Link: https://lore.kernel.org/r/20210810151432.9228-1-a.fatoum@pengutronix.de
Signed-off-by: Abel Vesa <abel.vesa@nxp.com>

1 files changed, 4 insertions, 3 deletions

diff --git a/drivers/clk/imx/clk-imx8mq.c b/drivers/clk/imx/clk-imx8mq.c
index c491bc9c61ce..83cc2b1c3294 100644
--- a/drivers/clk/imx/clk-imx8mq.c
+++ b/drivers/clk/imx/clk-imx8mq.c
@@ -449,11 +449,12 @@ static int imx8mq_clocks_probe(struct platform_device *pdev)
 
 	/*
 	 * DRAM clocks are manipulated from TF-A outside clock framework.
-	 * Mark with GET_RATE_NOCACHE to always read div value from hardware
+	 * The fw_managed helper sets GET_RATE_NOCACHE and clears SET_PARENT_GATE
+	 * as div value should always be read from hardware
 	 */
 	hws[IMX8MQ_CLK_DRAM_CORE] = imx_clk_hw_mux2_flags("dram_core_clk", base + 0x9800, 24, 1, imx8mq_dram_core_sels, ARRAY_SIZE(imx8mq_dram_core_sels), CLK_IS_CRITICAL);
-	hws[IMX8MQ_CLK_DRAM_ALT] = __imx8m_clk_hw_composite("dram_alt", imx8mq_dram_alt_sels, base + 0xa000, CLK_GET_RATE_NOCACHE);
-	hws[IMX8MQ_CLK_DRAM_APB] = __imx8m_clk_hw_composite("dram_apb", imx8mq_dram_apb_sels, base + 0xa080, CLK_IS_CRITICAL | CLK_GET_RATE_NOCACHE);
+	hws[IMX8MQ_CLK_DRAM_ALT] = imx8m_clk_hw_fw_managed_composite("dram_alt", imx8mq_dram_alt_sels, base + 0xa000);
+	hws[IMX8MQ_CLK_DRAM_APB] = imx8m_clk_hw_fw_managed_composite_critical("dram_apb", imx8mq_dram_apb_sels, base + 0xa080);
 
 	/* IP */
 	hws[IMX8MQ_CLK_VPU_G1] = imx8m_clk_hw_composite("vpu_g1", imx8mq_vpu_g1_sels, base + 0xa100);