imx8: add basic cpu support

Add basic cpu support, including cpu revision, cpu type,
cpu core detection.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Anatolij Gustschin <agust@denx.de>
Cc: Stefano Babic <sbabic@denx.de>

arch/arm/mach-imx/imx8/Makefile

@@ -0,0 +1,7 @@
+#
+# Copyright 2018 NXP
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+obj-y += cpu.o

arch/arm/mach-imx/imx8/cpu.c

@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2018 NXP
+ */
+
+#include <common.h>
+#include <clk.h>
+#include <dm.h>
+#include <dm/device-internal.h>
+#include <dm/lists.h>
+#include <dm/uclass.h>
+#include <errno.h>
+#include <asm/arch/sci/sci.h>
+#include <asm/arch-imx/cpu.h>
+#include <asm/armv8/cpu.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+u32 get_cpu_rev(void)
+{
+	u32 id = 0, rev = 0;
+	int ret;
+
+	ret = sc_misc_get_control(-1, SC_R_SYSTEM, SC_C_ID, &id);
+	if (ret)
+		return 0;
+
+	rev = (id >> 5)  & 0xf;
+	id = (id & 0x1f) + MXC_SOC_IMX8;  /* Dummy ID for chip */
+
+	return (id << 12) | rev;
+}
+
+#ifdef CONFIG_DISPLAY_CPUINFO
+const char *get_imx8_type(u32 imxtype)
+{
+	switch (imxtype) {
+	case MXC_CPU_IMX8QXP:
+		return "8QXP";
+	default:
+		return "??";
+	}
+}
+
+const char *get_imx8_rev(u32 rev)
+{
+	switch (rev) {
+	case CHIP_REV_A:
+		return "A";
+	case CHIP_REV_B:
+		return "B";
+	default:
+		return "?";
+	}
+}
+
+const char *get_core_name(void)
+{
+	if (is_cortex_a35())
+		return "A35";
+	else
+		return "?";
+}
+
+int print_cpuinfo(void)
+{
+	struct udevice *dev;
+	struct clk cpu_clk;
+	int ret;
+
+	ret = uclass_get_device(UCLASS_CPU, 0, &dev);
+	if (ret)
+		return 0;
+
+	ret = clk_get_by_index(dev, 0, &cpu_clk);
+	if (ret) {
+		dev_err(dev, "failed to clk\n");
+		return 0;
+	}
+
+	u32 cpurev;
+
+	cpurev = get_cpu_rev();
+
+	printf("CPU:   Freescale i.MX%s rev%s %s at %ld MHz\n",
+	       get_imx8_type((cpurev & 0xFF000) >> 12),
+	       get_imx8_rev((cpurev & 0xFFF)),
+	       get_core_name(),
+	       clk_get_rate(&cpu_clk) / 1000000);
+
+	return 0;
+}
+#endif