imx: add i.MX8MN DDR4 board support

Support pinctrl/clk/sdhc, include ddr4 timing data.

Log:
U-Boot SPL 2019.10-rc3-00356-g497c500423-dirty (Sep 16 2019 - 10:54:58 +0800)
Normal Boot
Trying to boot from BOOTROM
image offset 0x8000, pagesize 0x200, ivt offset 0x0

U-Boot 2019.10-rc3-00356-g497c500423-dirty (Sep 16 2019 - 10:54:58 +0800)

CPU:   Freescale i.MX8MNano rev1.0 at 24 MHz
Reset cause: POR
Model: NXP i.MX8MNano DDR4 EVK board
DRAM:  2 GiB
MMC:   FSL_SDHC: 1, FSL_SDHC: 2
Loading Environment from MMC... *** Warning - bad CRC, using default environment

In:    serial
Out:   serial
Err:   serial
Net:   No ethernet found.
Hit any key to stop autoboot:  0

Signed-off-by: Peng Fan <peng.fan@nxp.com>

board/freescale/imx8mn_evk/Kconfig

@@ -0,0 +1,14 @@
+if TARGET_IMX8MN_EVK
+
+config SYS_BOARD
+	default "imx8mn_evk"
+
+config SYS_VENDOR
+	default "freescale"
+
+config SYS_CONFIG_NAME
+	default "imx8mn_evk"
+
+source "board/freescale/common/Kconfig"
+
+endif

board/freescale/imx8mn_evk/MAINTAINERS

@@ -0,0 +1,6 @@
+i.MX8MM EVK BOARD
+M:	Peng Fan <peng.fan@nxp.com>
+S:	Maintained
+F:	board/freescale/imx8mn_evk/
+F:	include/configs/imx8mn_evk.h
+F:	configs/imx8mn_ddr4_evk_defconfig

board/freescale/imx8mn_evk/Makefile

@@ -0,0 +1,12 @@
+#
+# Copyright 2018 NXP
+#
+# SPDX-License-Identifier:      GPL-2.0+
+#
+
+obj-y += imx8mn_evk.o
+
+ifdef CONFIG_SPL_BUILD
+obj-y += spl.o
+obj-$(CONFIG_IMX8M_DDR4) += ddr4_timing.o
+endif

board/freescale/imx8mn_evk/imx8mn_evk.c

@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2019 NXP
+ */
+
+#include <common.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+int dram_init(void)
+{
+	gd->ram_size = PHYS_SDRAM_SIZE;
+
+	return 0;
+}
+
+int board_init(void)
+{
+	return 0;
+}
+
+int board_late_init(void)
+{
+#ifdef CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
+	env_set("board_name", "DDR4 EVK");
+	env_set("board_rev", "iMX8MN");
+#endif
+	return 0;
+}

board/freescale/imx8mn_evk/spl.c

@@ -0,0 +1,123 @@
+/*
+ * Copyright 2018-2019 NXP
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <spl.h>
+#include <asm/io.h>
+#include <asm/mach-imx/iomux-v3.h>
+#include <asm/arch/clock.h>
+#include <asm/arch/imx8mn_pins.h>
+#include <asm/arch/sys_proto.h>
+#include <asm/mach-imx/boot_mode.h>
+#include <asm/arch/ddr.h>
+
+#include <dm/uclass.h>
+#include <dm/device.h>
+#include <dm/uclass-internal.h>
+#include <dm/device-internal.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+int spl_board_boot_device(enum boot_device boot_dev_spl)
+{
+	return BOOT_DEVICE_BOOTROM;
+}
+
+void spl_dram_init(void)
+{
+	ddr_init(&dram_timing);
+}
+
+void spl_board_init(void)
+{
+	struct udevice *dev;
+	int ret;
+
+	puts("Normal Boot\n");
+
+	ret = uclass_get_device_by_name(UCLASS_CLK,
+					"clock-controller@30380000",
+					&dev);
+	if (ret < 0)
+		printf("Failed to find clock node. Check device tree\n");
+}
+
+#ifdef CONFIG_SPL_LOAD_FIT
+int board_fit_config_name_match(const char *name)
+{
+	/* Just empty function now - can't decide what to choose */
+	debug("%s: %s\n", __func__, name);
+
+	return 0;
+}
+#endif
+
+#define UART_PAD_CTRL	(PAD_CTL_DSE6 | PAD_CTL_FSEL1)
+#define WDOG_PAD_CTRL	(PAD_CTL_DSE6 | PAD_CTL_ODE | PAD_CTL_PUE | PAD_CTL_PE)
+
+static iomux_v3_cfg_t const uart_pads[] = {
+	IMX8MN_PAD_UART2_RXD__UART2_DCE_RX | MUX_PAD_CTRL(UART_PAD_CTRL),
+	IMX8MN_PAD_UART2_TXD__UART2_DCE_TX | MUX_PAD_CTRL(UART_PAD_CTRL),
+};
+
+static iomux_v3_cfg_t const wdog_pads[] = {
+	IMX8MN_PAD_GPIO1_IO02__WDOG1_WDOG_B  | MUX_PAD_CTRL(WDOG_PAD_CTRL),
+};
+
+int board_early_init_f(void)
+{
+	struct wdog_regs *wdog = (struct wdog_regs *)WDOG1_BASE_ADDR;
+
+	imx_iomux_v3_setup_multiple_pads(wdog_pads, ARRAY_SIZE(wdog_pads));
+
+	set_wdog_reset(wdog);
+
+	imx_iomux_v3_setup_multiple_pads(uart_pads, ARRAY_SIZE(uart_pads));
+
+	init_uart_clk(1);
+
+	return 0;
+}
+
+void board_init_f(ulong dummy)
+{
+	int ret;
+
+	arch_cpu_init();
+
+	init_uart_clk(1);
+
+	board_early_init_f();
+
+	timer_init();
+
+	preloader_console_init();
+
+	/* Clear the BSS. */
+	memset(__bss_start, 0, __bss_end - __bss_start);
+
+	ret = spl_init();
+	if (ret) {
+		debug("spl_init() failed: %d\n", ret);
+		hang();
+	}
+
+	enable_tzc380();
+
+	/* DDR initialization */
+	spl_dram_init();
+
+	board_init_r(NULL, 0);
+}
+
+int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	puts("resetting ...\n");
+
+	reset_cpu(WDOG1_BASE_ADDR);
+
+	return 0;
+}