[PATCH v2 4/5] ARM: i.MX8MP: don't reparent GIC from BootROM default

[Ahmad Fatoum]

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 at pengutronix.de>
---
v1 -> v2:
   User if (!8mp) condition for clarity and move comment into it (Lucas)
---
 arch/arm/mach-imx/imx8m.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/arch/arm/mach-imx/imx8m.c b/arch/arm/mach-imx/imx8m.c
index 56330cef500c..6286ab7344bc 100644
--- a/arch/arm/mach-imx/imx8m.c
+++ b/arch/arm/mach-imx/imx8m.c
@@ -100,12 +100,15 @@ 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_IMX8MP) {
+		/* 8MP ROM already set GIC to 400Mhz, system_pll1_800m with div = 2 */
+		/* For everything 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);
+	}
 
 	if (cpu_type == IMX_CPU_IMX8MN || cpu_type == IMX_CPU_IMX8MP)
 		pll3_freq = 600000000UL;
-- 
2.39.2