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path: root/drivers/clk/imx/clk-imx6ul.c
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Diffstat (limited to 'drivers/clk/imx/clk-imx6ul.c')
-rw-r--r--drivers/clk/imx/clk-imx6ul.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/drivers/clk/imx/clk-imx6ul.c b/drivers/clk/imx/clk-imx6ul.c
index aaa36650695f..01718d05e952 100644
--- a/drivers/clk/imx/clk-imx6ul.c
+++ b/drivers/clk/imx/clk-imx6ul.c
@@ -407,6 +407,24 @@ static void __init imx6ul_clocks_init(struct device_node *ccm_node)
clk_data.clk_num = ARRAY_SIZE(clks);
of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
+ /*
+ * Lower the AHB clock rate before changing the parent clock source,
+ * as AHB clock rate can NOT be higher than 133MHz, but its parent
+ * will be switched from 396MHz PFD to 528MHz PLL in order to increase
+ * AXI clock rate, so we need to lower AHB rate first to make sure at
+ * any time, AHB rate is <= 133MHz.
+ */
+ clk_set_rate(clks[IMX6UL_CLK_AHB], 99000000);
+
+ /* Change periph_pre clock to pll2_bus to adjust AXI rate to 264MHz */
+ clk_set_parent(clks[IMX6UL_CLK_PERIPH_CLK2_SEL], clks[IMX6UL_CLK_PLL3_USB_OTG]);
+ clk_set_parent(clks[IMX6UL_CLK_PERIPH], clks[IMX6UL_CLK_PERIPH_CLK2]);
+ clk_set_parent(clks[IMX6UL_CLK_PERIPH_PRE], clks[IMX6UL_CLK_PLL2_BUS]);
+ clk_set_parent(clks[IMX6UL_CLK_PERIPH], clks[IMX6UL_CLK_PERIPH_PRE]);
+
+ /* Make sure AHB rate is 132MHz */
+ clk_set_rate(clks[IMX6UL_CLK_AHB], 132000000);
+
/* set perclk to from OSC */
clk_set_parent(clks[IMX6UL_CLK_PERCLK_SEL], clks[IMX6UL_CLK_OSC]);