imx: imx8mm: Add support for Kontron Electronics SL/BL i.MX8M-Mini boards (N801x)

The Kontron SoM-Line i.MX8MM (N801x) by Kontron Electronics GmbH is a SoM
module with an i.MX8M-Mini SoC, 1/2/4 GB LPDDR4 RAM, SPI NOR, eMMC and PMIC.

The matching evaluation boards (Board-Line) have 2 Ethernets, USB 2.0, HDMI/LVDS,
SD card, CAN, RS485 and much more.

Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Reviewed-by: Stefano Babic <sbabic@denx.de>
Tested-by: Heiko Thiery <heiko.thiery@gmail.com>
diff --git a/board/kontron/sl-mx8mm/spl.c b/board/kontron/sl-mx8mm/spl.c
new file mode 100644
index 0000000..4ef03c8
--- /dev/null
+++ b/board/kontron/sl-mx8mm/spl.c
@@ -0,0 +1,321 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2019 Kontron Electronics GmbH
+ */
+
+#include <asm/arch/imx8mm_pins.h>
+#include <asm/arch/clock.h>
+#include <asm/arch/ddr.h>
+#include <asm/arch/imx-regs.h>
+#include <asm/arch/sys_proto.h>
+#include <asm/global_data.h>
+#include <asm/gpio.h>
+#include <asm/mach-imx/boot_mode.h>
+#include <asm/mach-imx/iomux-v3.h>
+#include <dm/uclass.h>
+#include <hang.h>
+#include <i2c.h>
+#include <init.h>
+#include <linux/errno.h>
+#include <linux/delay.h>
+#include <power/pca9450.h>
+#include <power/pmic.h>
+#include <spl.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+enum {
+	BOARD_TYPE_KTN_N801X,
+	BOARD_TYPE_KTN_N801X_LVDS,
+	BOARD_TYPE_MAX
+};
+
+#define GPIO_PAD_CTRL	(PAD_CTL_DSE6 | PAD_CTL_ODE | PAD_CTL_PUE | PAD_CTL_PE)
+#define I2C_PAD_CTRL	(PAD_CTL_DSE6 | PAD_CTL_HYS | PAD_CTL_PUE)
+#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)
+
+#define TOUCH_RESET_GPIO	IMX_GPIO_NR(3, 23)
+
+static iomux_v3_cfg_t const i2c1_pads[] = {
+	IMX8MM_PAD_I2C1_SCL_I2C1_SCL | MUX_PAD_CTRL(I2C_PAD_CTRL) | MUX_MODE_SION,
+	IMX8MM_PAD_I2C1_SDA_I2C1_SDA | MUX_PAD_CTRL(I2C_PAD_CTRL) | MUX_MODE_SION
+};
+
+static iomux_v3_cfg_t const i2c2_pads[] = {
+	IMX8MM_PAD_I2C2_SCL_I2C2_SCL | MUX_PAD_CTRL(I2C_PAD_CTRL) | MUX_MODE_SION,
+	IMX8MM_PAD_I2C2_SDA_I2C2_SDA | MUX_PAD_CTRL(I2C_PAD_CTRL) | MUX_MODE_SION
+};
+
+static iomux_v3_cfg_t const touch_gpio[] = {
+	IMX8MM_PAD_SAI5_RXD2_GPIO3_IO23 | MUX_PAD_CTRL(GPIO_PAD_CTRL)
+};
+
+static iomux_v3_cfg_t const uart_pads[] = {
+	IMX8MM_PAD_UART3_RXD_UART3_RX | MUX_PAD_CTRL(UART_PAD_CTRL),
+	IMX8MM_PAD_UART3_TXD_UART3_TX | MUX_PAD_CTRL(UART_PAD_CTRL),
+};
+
+static iomux_v3_cfg_t const wdog_pads[] = {
+	IMX8MM_PAD_GPIO1_IO02_WDOG1_WDOG_B  | MUX_PAD_CTRL(WDOG_PAD_CTRL),
+};
+
+int spl_board_boot_device(enum boot_device boot_dev_spl)
+{
+	switch (boot_dev_spl) {
+	case USB_BOOT:
+		return BOOT_DEVICE_BOARD;
+	case SPI_NOR_BOOT:
+		return BOOT_DEVICE_SPI;
+	case SD1_BOOT:
+	case MMC1_BOOT:
+		return BOOT_DEVICE_MMC1;
+	case SD2_BOOT:
+	case MMC2_BOOT:
+		return BOOT_DEVICE_MMC2;
+	default:
+		return BOOT_DEVICE_NONE;
+	}
+}
+
+bool check_ram_available(long size)
+{
+	long sz = get_ram_size((long *)PHYS_SDRAM, size);
+
+	if (sz == size)
+		return true;
+
+	return false;
+}
+
+static void spl_dram_init(void)
+{
+	u32 size = 0;
+
+	/*
+	 * Try the default DDR settings in lpddr4_timing.c to
+	 * comply with the Micron 4GB DDR.
+	 */
+	if (!ddr_init(&dram_timing) && check_ram_available(SZ_4G)) {
+		size = 4;
+	} else {
+		/*
+		 * Overwrite some values to comply with the Micron 1GB/2GB DDRs.
+		 */
+		dram_timing.ddrc_cfg[2].val = 0xa1080020;
+		dram_timing.ddrc_cfg[37].val = 0x1f;
+
+		dram_timing.fsp_msg[0].fsp_cfg[9].val = 0x110;
+		dram_timing.fsp_msg[0].fsp_cfg[21].val = 0x1;
+		dram_timing.fsp_msg[1].fsp_cfg[10].val = 0x110;
+		dram_timing.fsp_msg[1].fsp_cfg[22].val = 0x1;
+		dram_timing.fsp_msg[2].fsp_cfg[10].val = 0x110;
+		dram_timing.fsp_msg[2].fsp_cfg[22].val = 0x1;
+		dram_timing.fsp_msg[3].fsp_cfg[10].val = 0x110;
+		dram_timing.fsp_msg[3].fsp_cfg[22].val = 0x1;
+
+		if (!ddr_init(&dram_timing)) {
+			if (check_ram_available(SZ_2G))
+				size = 2;
+			else if (check_ram_available(SZ_1G))
+				size = 1;
+		}
+	}
+
+	if (size == 0) {
+		printf("Failed to initialize DDR RAM!\n");
+		size = 1;
+	}
+
+	printf("Kontron SL i.MX8MM (N801X) module, %u GB RAM detected\n", size);
+	writel(size, M4_BOOTROM_BASE_ADDR);
+}
+
+static void touch_reset(void)
+{
+	/*
+	 * Toggle the reset of the touch panel.
+	 */
+	imx_iomux_v3_setup_multiple_pads(touch_gpio, ARRAY_SIZE(touch_gpio));
+
+	gpio_request(TOUCH_RESET_GPIO, "touch_reset");
+	gpio_direction_output(TOUCH_RESET_GPIO, 0);
+	mdelay(20);
+	gpio_direction_output(TOUCH_RESET_GPIO, 1);
+	mdelay(20);
+}
+
+static int i2c_detect(u8 bus, u16 addr)
+{
+	struct udevice *udev;
+	int ret;
+
+	/*
+	 * Try to probe the touch controller to check if an LVDS panel is
+	 * connected.
+	 */
+	ret = i2c_get_chip_for_busnum(bus, addr, 0, &udev);
+	if (ret == 0)
+		return 0;
+
+	return 1;
+}
+
+int do_board_detect(void)
+{
+	bool lvds = false;
+
+	/*
+	 * Check the I2C touch controller to detect a LVDS panel.
+	 */
+	imx_iomux_v3_setup_multiple_pads(i2c2_pads, ARRAY_SIZE(i2c2_pads));
+	touch_reset();
+
+	if (i2c_detect(1, 0x5d) == 0) {
+		printf("Touch controller detected, assuming LVDS panel...\n");
+		lvds = true;
+	}
+
+	/*
+	 * Check the I2C PMIC to detect the deprecated SoM with DA9063.
+	 */
+	imx_iomux_v3_setup_multiple_pads(i2c1_pads, ARRAY_SIZE(i2c1_pads));
+
+	if (i2c_detect(0, 0x58) == 0) {
+		printf("### ATTENTION: DEPRECATED SOM REVISION (N8010 Rev0) DETECTED! ###\n");
+		printf("###  THIS HW IS NOT SUPPRTED AND BOOTING WILL PROBABLY FAIL   ###\n");
+		printf("###             PLEASE UPGRADE TO LATEST MODULE               ###\n");
+	}
+
+	if (lvds)
+		gd->board_type = BOARD_TYPE_KTN_N801X_LVDS;
+	else
+		gd->board_type = BOARD_TYPE_KTN_N801X;
+
+	return 0;
+}
+
+int board_fit_config_name_match(const char *name)
+{
+	if (gd->board_type == BOARD_TYPE_KTN_N801X_LVDS && is_imx8mm() &&
+	    !strncmp(name, "imx8mm-kontron-n801x-s-lvds", 27))
+		return 0;
+
+	if (gd->board_type == BOARD_TYPE_KTN_N801X && is_imx8mm() &&
+	    !strncmp(name, "imx8mm-kontron-n801x-s", 22))
+		return 0;
+
+	return -1;
+}
+
+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");
+}
+
+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));
+
+	return 0;
+}
+
+static int power_init_board(void)
+{
+	struct udevice *dev;
+	int ret  = pmic_get("pmic@25", &dev);
+
+	if (ret == -ENODEV)
+		puts("No pmic found\n");
+
+	if (ret)
+		return ret;
+
+	/* BUCKxOUT_DVS0/1 control BUCK123 output, clear PRESET_EN */
+	pmic_reg_write(dev, PCA9450_BUCK123_DVS, 0x29);
+
+	/* increase VDD_DRAM to 0.95V for 1.5GHz DDR */
+	pmic_reg_write(dev, PCA9450_BUCK3OUT_DVS0, 0x1c);
+
+	/* set VDD_SNVS_0V8 from default 0.85V to 0.8V */
+	pmic_reg_write(dev, PCA9450_LDO2CTRL, 0xC0);
+
+	/* set WDOG_B_CFG to cold reset */
+	pmic_reg_write(dev, PCA9450_RESET_CTRL, 0xA1);
+
+	return 0;
+}
+
+void board_init_f(ulong dummy)
+{
+	int ret;
+
+	arch_cpu_init();
+
+	init_uart_clk(2);
+
+	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();
+
+	/* PMIC initialization */
+	power_init_board();
+
+	/* DDR initialization */
+	spl_dram_init();
+
+	/* Detect the board type */
+	do_board_detect();
+
+	board_init_r(NULL, 0);
+}
+
+void board_boot_order(u32 *spl_boot_list)
+{
+	u32 bootdev = spl_boot_device();
+
+	/*
+	 * The default boot fuse settings use the SD card (MMC2) as primary
+	 * boot device, but allow SPI NOR as a fallback boot device.
+	 * We can't detect the fallback case and spl_boot_device() will return
+	 * BOOT_DEVICE_MMC2 despite the actual boot device being SPI NOR.
+	 * Therefore we try to load U-Boot proper vom SPI NOR after loading
+	 * from MMC has failed.
+	 */
+	spl_boot_list[0] = bootdev;
+
+	switch (bootdev) {
+	case BOOT_DEVICE_MMC1:
+	case BOOT_DEVICE_MMC2:
+		spl_boot_list[1] = BOOT_DEVICE_SPI;
+		break;
+	}
+}