clk: imx8m: Set CLK_GET_RATE_NOCACHE on dram clocks

These clocks are only modified as part of DRAM frequency switches during
which DRAM itself is briefly inaccessible. The switch is performed with
a SMC call to by TF-A which runs from a SRAM area; upon returning to
linux several clocks bits are modified and we need to update them.

For rate bits an easy solution is to just mark with
CLK_GET_RATE_NOCACHE so that new rates are always read back from
registers.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Abel Vesa <abel.vesa@nxp.com>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
diff --git a/drivers/clk/imx/clk-imx8mn.c b/drivers/clk/imx/clk-imx8mn.c
index 9f5a5a5..de905e2 100644
--- a/drivers/clk/imx/clk-imx8mn.c
+++ b/drivers/clk/imx/clk-imx8mn.c
@@ -430,8 +430,14 @@ static int imx8mn_clocks_probe(struct platform_device *pdev)
 	clks[IMX8MN_CLK_IPG_ROOT] = imx_clk_divider2("ipg_root", "ahb", base + 0x9080, 0, 1);
 	clks[IMX8MN_CLK_IPG_AUDIO_ROOT] = imx_clk_divider2("ipg_audio_root", "audio_ahb", base + 0x9180, 0, 1);
 	clks[IMX8MN_CLK_DRAM_CORE] = imx_clk_mux2_flags("dram_core_clk", base + 0x9800, 24, 1, imx8mn_dram_core_sels, ARRAY_SIZE(imx8mn_dram_core_sels), CLK_IS_CRITICAL);
-	clks[IMX8MN_CLK_DRAM_ALT] = imx8m_clk_composite("dram_alt", imx8mn_dram_alt_sels, base + 0xa000);
-	clks[IMX8MN_CLK_DRAM_APB] = imx8m_clk_composite_critical("dram_apb", imx8mn_dram_apb_sels, base + 0xa080);
+
+	/*
+	 * DRAM clocks are manipulated from TF-A outside clock framework.
+	 * Mark with GET_RATE_NOCACHE to always read div value from hardware
+	 */
+	clks[IMX8MN_CLK_DRAM_ALT] = __imx8m_clk_composite("dram_alt", imx8mn_dram_alt_sels, base + 0xa000, CLK_GET_RATE_NOCACHE);
+	clks[IMX8MN_CLK_DRAM_APB] = __imx8m_clk_composite("dram_apb", imx8mn_dram_apb_sels, base + 0xa080, CLK_IS_CRITICAL | CLK_GET_RATE_NOCACHE);
+
 	clks[IMX8MN_CLK_DISP_PIXEL] = imx8m_clk_composite("disp_pixel", imx8mn_disp_pixel_sels, base + 0xa500);
 	clks[IMX8MN_CLK_SAI2] = imx8m_clk_composite("sai2", imx8mn_sai2_sels, base + 0xa600);
 	clks[IMX8MN_CLK_SAI3] = imx8m_clk_composite("sai3", imx8mn_sai3_sels, base + 0xa680);