[PATCH V2 1/4] clk: imx: imx8mq: fix a53 cpu clock

[Peng Fan]

From: Peng Fan <peng.fan@xxxxxxx>

The A53 CCM clk root only accepts input up to 1GHz, CCM A53 root
signoff timing is 1Ghz, however the A53 core which sources from CCM
root could run above 1GHz which voilates the CCM.

There is a CORE_SEL slice before A53 core, we need configure the
CORE_SEL slice source from ARM PLL, not A53 CCM clk root.

The A53 CCM clk root should only be used when need to change ARM PLL
frequency.

Add arm_a53_core clk that could source from arm_a53_div and arm_pll_out.
Configure a53 ccm root sources from 800MHz sys pll
Configure a53 core sources from arm_pll_out
Mark arm_a53_core as critical clock

Fixes: db27e40b27f1 ("clk: imx8mq: Add the missing ARM clock")
Reviewed-by: Jacky Bai <ping.bai@xxxxxxx>
Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
---

V2:
 None

 drivers/clk/imx/clk-imx8mq.c             | 16 ++++++++++++----
 include/dt-bindings/clock/imx8mq-clock.h |  4 +++-
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/clk/imx/clk-imx8mq.c b/drivers/clk/imx/clk-imx8mq.c
index b031183ff427..82a16b8e98a9 100644
--- a/drivers/clk/imx/clk-imx8mq.c
+++ b/drivers/clk/imx/clk-imx8mq.c
@@ -41,6 +41,8 @@ static const char * const video2_pll_out_sels[] = {"video2_pll1_ref_sel", };
 static const char * const imx8mq_a53_sels[] = {"osc_25m", "arm_pll_out", "sys2_pll_500m", "sys2_pll_1000m",
 					"sys1_pll_800m", "sys1_pll_400m", "audio_pll1_out", "sys3_pll_out", };
 
+static const char * const imx8mq_a53_core_sels[] = {"arm_a53_div", "arm_pll_out", };
+
 static const char * const imx8mq_arm_m4_sels[] = {"osc_25m", "sys2_pll_200m", "sys2_pll_250m", "sys1_pll_266m",
 					"sys1_pll_800m", "audio_pll1_out", "video_pll1_out", "sys3_pll_out", };
 
@@ -411,6 +413,9 @@ static int imx8mq_clocks_probe(struct platform_device *pdev)
 	hws[IMX8MQ_CLK_GPU_CORE_DIV] = imx8m_clk_hw_composite_core("gpu_core_div", imx8mq_gpu_core_sels, base + 0x8180);
 	hws[IMX8MQ_CLK_GPU_SHADER_DIV] = imx8m_clk_hw_composite("gpu_shader_div", imx8mq_gpu_shader_sels, base + 0x8200);
 
+	/* CORE SEL */
+	hws[IMX8MQ_CLK_A53_CORE] = imx_clk_hw_mux2_flags("arm_a53_core", base + 0x9880, 24, 1, imx8mq_a53_core_sels, ARRAY_SIZE(imx8mq_a53_core_sels), CLK_IS_CRITICAL);
+
 	/* BUS */
 	hws[IMX8MQ_CLK_MAIN_AXI] = imx8m_clk_hw_composite_critical("main_axi", imx8mq_main_axi_sels, base + 0x8800);
 	hws[IMX8MQ_CLK_ENET_AXI] = imx8m_clk_hw_composite("enet_axi", imx8mq_enet_axi_sels, base + 0x8880);
@@ -574,11 +579,14 @@ static int imx8mq_clocks_probe(struct platform_device *pdev)
 	hws[IMX8MQ_GPT_3M_CLK] = imx_clk_hw_fixed_factor("gpt_3m", "osc_25m", 1, 8);
 	hws[IMX8MQ_CLK_DRAM_ALT_ROOT] = imx_clk_hw_fixed_factor("dram_alt_root", "dram_alt", 1, 4);
 
-	hws[IMX8MQ_CLK_ARM] = imx_clk_hw_cpu("arm", "arm_a53_div",
-					   hws[IMX8MQ_CLK_A53_DIV]->clk,
-					   hws[IMX8MQ_CLK_A53_SRC]->clk,
+	clk_hw_set_parent(hws[IMX8MQ_CLK_A53_SRC], hws[IMX8MQ_SYS1_PLL_800M]);
+	clk_hw_set_parent(hws[IMX8MQ_CLK_A53_CORE], hws[IMX8MQ_ARM_PLL_OUT]);
+
+	hws[IMX8MQ_CLK_ARM] = imx_clk_hw_cpu("arm", "arm_a53_core",
+					   hws[IMX8MQ_CLK_A53_CORE]->clk,
+					   hws[IMX8MQ_CLK_A53_CORE]->clk,
 					   hws[IMX8MQ_ARM_PLL_OUT]->clk,
-					   hws[IMX8MQ_SYS1_PLL_800M]->clk);
+					   hws[IMX8MQ_CLK_A53_DIV]->clk);
 
 	imx_check_clk_hws(hws, IMX8MQ_CLK_END);
 
diff --git a/include/dt-bindings/clock/imx8mq-clock.h b/include/dt-bindings/clock/imx8mq-clock.h
index 3bab9b21c8d7..ac71e9e502b8 100644
--- a/include/dt-bindings/clock/imx8mq-clock.h
+++ b/include/dt-bindings/clock/imx8mq-clock.h
@@ -424,6 +424,8 @@
 #define IMX8MQ_SYS2_PLL_500M_CG			283
 #define IMX8MQ_SYS2_PLL_1000M_CG		284
 
-#define IMX8MQ_CLK_END				285
+#define IMX8MQ_CLK_A53_CORE			285
+
+#define IMX8MQ_CLK_END				286
 
 #endif /* __DT_BINDINGS_CLOCK_IMX8MQ_H */
-- 
2.16.4