[PATCH 4/5] ARM: i.MX8MP: don't reparent GIC from BootROM default

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

On i.MX8MP, GIC can run at up to 400 MHz in nominal drive mode and up
to 500 MHz in overdrive mode. We currently configure unconditionally
to 100 MHz on i.MX8MP.

The BootROM default is running it on 400 MHz, which works well for us on
the i.MX8MP, so skip the GIC configuration on the i.MX8MP.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 arch/arm/mach-imx/imx8m.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/arch/arm/mach-imx/imx8m.c b/arch/arm/mach-imx/imx8m.c
index 56330cef500c..0966f7fdf076 100644
--- a/arch/arm/mach-imx/imx8m.c
+++ b/arch/arm/mach-imx/imx8m.c
@@ -100,13 +100,6 @@ static void __imx8m_early_clock_init(int cpu_type)
 		INTPLL_DIV20_CLKE_MASK;
 	writel(val, ana + IMX8MM_CCM_ANALOG_SYS_PLL2_GEN_CTRL);
 
-	/* config GIC to sys_pll2_100m */
-	imx8m_ccgr_clock_disable(IMX8M_CCM_CCGR_GIC);
-	imx8m_clock_set_target_val(IMX8M_GIC_CLK_ROOT,
-				   IMX8M_CCM_TARGET_ROOTn_ENABLE |
-				   IMX8M_CCM_TARGET_ROOTn_MUX(3));
-	imx8m_ccgr_clock_enable(IMX8M_CCM_CCGR_GIC);
-
 	if (cpu_type == IMX_CPU_IMX8MN || cpu_type == IMX_CPU_IMX8MP)
 		pll3_freq = 600000000UL;
 	else
@@ -118,11 +111,20 @@ static void __imx8m_early_clock_init(int cpu_type)
 
 	if (cpu_type == IMX_CPU_IMX8MP) {
 		/* 8MP ROM already set NOC to 800Mhz, only need to configure NOC_IO clk to 600Mhz */
+		/* 8MP ROM already set GIC to 400Mhz, system_pll1_800m with div = 2 */
 		imx8m_clock_set_target_val(IMX8M_NOC_IO_CLK_ROOT,
 					   IMX8M_CCM_TARGET_ROOTn_ENABLE |
 					   IMX8M_CCM_TARGET_ROOTn_MUX(2));
+	} else {
+		/* config GIC to sys_pll2_100m */
+		imx8m_ccgr_clock_disable(IMX8M_CCM_CCGR_GIC);
+		imx8m_clock_set_target_val(IMX8M_GIC_CLK_ROOT,
+					   IMX8M_CCM_TARGET_ROOTn_ENABLE |
+					   IMX8M_CCM_TARGET_ROOTn_MUX(3));
+		imx8m_ccgr_clock_enable(IMX8M_CCM_CCGR_GIC);
 	}
 
+
 	clrsetbits_le32(ccm + IMX8M_CCM_TARGET_ROOTn(IMX8M_ARM_A53_CLK_ROOT),
 			IMX8M_CCM_TARGET_ROOTn_MUX(7),
 			IMX8M_CCM_TARGET_ROOTn_MUX(2));
-- 
2.39.2