[PATCH 12/24] imx8mq: Set ARM core clock directly from ARM PLL

[Peng Fan]

For ARM core clock, there are two input branches, and can select via mux:
one from ARM PLL directly, second from CCM A53 clock root.

Currently we are using second branch. But IC confirmed the CCM A53 root
signoff timing is 1Ghz, so we should switch to input from ARM PLL directly.

This patch fixes the CORE SEL slice configuration and switch ARM clock
to ARM PLL.

Signed-off-by: Peng Fan <peng.fan at nxp.com>
---
 arch/arm/include/asm/arch-imx8m/clock_imx8mq.h |  3 +-
 arch/arm/mach-imx/imx8m/clock_imx8mq.c         | 49 +++++++++++++++++---------
 2 files changed, 35 insertions(+), 17 deletions(-)

diff --git a/arch/arm/include/asm/arch-imx8m/clock_imx8mq.h b/arch/arm/include/asm/arch-imx8m/clock_imx8mq.h
index 38a6f5966b..9dda6ddc8c 100644
--- a/arch/arm/include/asm/arch-imx8m/clock_imx8mq.h
+++ b/arch/arm/include/asm/arch-imx8m/clock_imx8mq.h
@@ -153,6 +153,7 @@ enum clk_root_src {
 	EXT_CLK_3,
 	EXT_CLK_4,
 	OSC_27M_CLK,
+	ARM_A53_ALT_CLK,
 };
 
 /* CCGR index */
@@ -419,7 +420,7 @@ enum clk_src_index {
 
 enum frac_pll_out_val {
 	FRAC_PLL_OUT_1000M,
-	FRAC_PLL_OUT_1600M,
+	FRAC_PLL_OUT_800M,
 };
 
 void init_nand_clk(void);
diff --git a/arch/arm/mach-imx/imx8m/clock_imx8mq.c b/arch/arm/mach-imx/imx8m/clock_imx8mq.c
index 76104e4f92..fb85a8d06e 100644
--- a/arch/arm/mach-imx/imx8m/clock_imx8mq.c
+++ b/arch/arm/mach-imx/imx8m/clock_imx8mq.c
@@ -15,6 +15,8 @@
 
 static struct anamix_pll *ana_pll = (struct anamix_pll *)ANATOP_BASE_ADDR;
 
+static u32 get_root_clk(enum clk_root_index clock_id);
+
 static u32 decode_frac_pll(enum clk_root_src frac_pll)
 {
 	u32 pll_cfg0, pll_cfg1, pllout;
@@ -275,6 +277,8 @@ static u32 get_root_src_clk(enum clk_root_src root_src)
 	case SYSTEM_PLL2_50M_CLK:
 	case SYSTEM_PLL3_CLK:
 		return decode_sscg_pll(root_src);
+	case ARM_A53_ALT_CLK:
+		return get_root_clk(ARM_A53_CLK_ROOT);
 	default:
 		return 0;
 	}
@@ -322,13 +326,26 @@ int enable_i2c_clk(unsigned char enable, unsigned int i2c_num)
 	return 0;
 }
 
+u32 get_arm_core_clk(void)
+{
+	enum clk_root_src root_src;
+	u32 root_src_clk;
+
+	if (clock_get_src(CORE_SEL_CFG, &root_src) < 0)
+		return 0;
+
+	root_src_clk = get_root_src_clk(root_src);
+
+	return root_src_clk;
+}
+
 unsigned int mxc_get_clock(enum mxc_clock clk)
 {
 	u32 val;
 
-	switch(clk) {
+	switch (clk) {
 	case MXC_ARM_CLK:
-		return get_root_clk(ARM_A53_CLK_ROOT);
+		return get_arm_core_clk();
 	case MXC_IPG_CLK:
 		clock_get_target_val(IPG_CLK_ROOT, &val);
 		val = val & 0x3;
@@ -637,7 +654,7 @@ void dram_pll_init(ulong pll_val)
 static int frac_pll_init(u32 pll, enum frac_pll_out_val val)
 {
 	void __iomem *pll_cfg0, __iomem *pll_cfg1;
-	u32 val_cfg0, val_cfg1;
+	u32 val_cfg0, val_cfg1, divq;
 	int ret;
 
 	switch (pll) {
@@ -645,14 +662,17 @@ static int frac_pll_init(u32 pll, enum frac_pll_out_val val)
 		pll_cfg0 = &ana_pll->arm_pll_cfg0;
 		pll_cfg1 = &ana_pll->arm_pll_cfg1;
 
-		if (val == FRAC_PLL_OUT_1000M)
+		if (val == FRAC_PLL_OUT_1000M) {
 			val_cfg1 = FRAC_PLL_INT_DIV_CTL_VAL(49);
-		else
+			divq = 0;
+		} else {
 			val_cfg1 = FRAC_PLL_INT_DIV_CTL_VAL(79);
+			divq = 1;
+		}
 		val_cfg0 = FRAC_PLL_CLKE_MASK | FRAC_PLL_REFCLK_SEL_OSC_25M |
 			FRAC_PLL_LOCK_SEL_MASK | FRAC_PLL_NEWDIV_VAL_MASK |
 			FRAC_PLL_REFCLK_DIV_VAL(4) |
-			FRAC_PLL_OUTPUT_DIV_VAL(0);
+			FRAC_PLL_OUTPUT_DIV_VAL(divq);
 		break;
 	default:
 		return -EINVAL;
@@ -688,17 +708,14 @@ int clock_init(void)
 	 * We set ARM clock to 1Ghz for consumer, 800Mhz for industrial
 	 */
 	grade = get_cpu_temp_grade(NULL, NULL);
-	if (!grade) {
+	if (!grade)
 		frac_pll_init(ANATOP_ARM_PLL, FRAC_PLL_OUT_1000M);
-		clock_set_target_val(ARM_A53_CLK_ROOT, CLK_ROOT_ON |
-			     CLK_ROOT_SOURCE_SEL(1) |
-			     CLK_ROOT_POST_DIV(CLK_ROOT_POST_DIV1));
-	} else {
-		frac_pll_init(ANATOP_ARM_PLL, FRAC_PLL_OUT_1600M);
-		clock_set_target_val(ARM_A53_CLK_ROOT, CLK_ROOT_ON |
-			     CLK_ROOT_SOURCE_SEL(1) |
-			     CLK_ROOT_POST_DIV(CLK_ROOT_POST_DIV2));
-	}
+	else
+		frac_pll_init(ANATOP_ARM_PLL, FRAC_PLL_OUT_800M);
+
+	/* Bypass CCM A53 ROOT, Switch to ARM PLL -> MUX-> CPU */
+	clock_set_target_val(CORE_SEL_CFG, CLK_ROOT_SOURCE_SEL(1));
+
 	/*
 	 * According to ANAMIX SPEC
 	 * sys pll1 fixed at 800MHz
-- 
2.16.4