i.MX7ULP: Set A7 core frequency to 500Mhz for B0 chip

The normal target frequency for ULP A7 core is 500Mhz, but now ROM
set the core frequency to 413Mhz. So change it to 500Mhz in u-boot.

Signed-off-by: Ye Li <ye.li@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
diff --git a/arch/arm/mach-imx/mx7ulp/scg.c b/arch/arm/mach-imx/mx7ulp/scg.c
index a28a2bc..0d31352 100644
--- a/arch/arm/mach-imx/mx7ulp/scg.c
+++ b/arch/arm/mach-imx/mx7ulp/scg.c
@@ -1091,3 +1091,44 @@
 	debug("SCG RCCR Value: 0x%x\n", readl(&scg1_regs->rccr));
 	debug("SCG Clock Status: 0x%x\n", readl(&scg1_regs->csr));
 }
+
+void scg_a7_init_core_clk(void)
+{
+	u32 val = 0;
+
+	/*
+	 * The normal target frequency for ULP B0 is 500Mhz,
+	 * but ROM set it to 413Mhz, need to change SPLL PFD0 FRAC
+	 */
+	if (soc_rev() >= CHIP_REV_2_0) {
+		/* Switch RCCR SCG to SOSC, firstly check the SOSC is valid */
+		if ((readl(&scg1_regs->sosccsr) & SCG_SOSC_CSR_SOSCVLD_MASK)) {
+			val = readl(&scg1_regs->rccr);
+			val &= (~SCG_CCR_SCS_MASK);
+			val |= ((SCG_SCS_SYS_OSC) << SCG_CCR_SCS_SHIFT);
+			writel(val, &scg1_regs->rccr);
+
+			/* Switch the PLLS to SPLL clk */
+			val = readl(&scg1_regs->spllcfg);
+			val &= ~SCG_PLL_CFG_PLLSEL_MASK;
+			writel(val, &scg1_regs->spllcfg);
+
+			/*
+			 * Re-configure PFD0 to 19,
+			 * A7 SPLL(528MHz) * 18 / 19 = 500MHz
+			 */
+			scg_enable_pll_pfd(SCG_SPLL_PFD0_CLK, 19);
+
+			/* Switch the PLLS to SPLL PFD0 */
+			val = readl(&scg1_regs->spllcfg);
+			val |= SCG_PLL_CFG_PLLSEL_MASK;
+			writel(val, &scg1_regs->spllcfg);
+
+			/* Set RCCR SCG to SPLL clk out */
+			val = readl(&scg1_regs->rccr);
+			val &= (~SCG_CCR_SCS_MASK);
+			val |= ((SCG_SCS_SYS_PLL) << SCG_CCR_SCS_SHIFT);
+			writel(val, &scg1_regs->rccr);
+		}
+	}
+}