1 files changed, 145 insertions, 0 deletions
diff --git a/arch/arm/boards/nxp-imx8mp-evk/lowlevel.c b/arch/arm/boards/nxp-imx8mp-evk/lowlevel.c
new file mode 100644
index 0000000000..969947d2ec
--- /dev/null
+++ b/arch/arm/boards/nxp-imx8mp-evk/lowlevel.c
@@ -0,0 +1,145 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <io.h>
+#include <common.h>
+#include <debug_ll.h>
+#include <mach/imx/debug_ll.h>
+#include <firmware.h>
+#include <asm/mmu.h>
+#include <asm/cache.h>
+#include <asm/sections.h>
+#include <asm/barebox-arm.h>
+#include <asm/barebox-arm-head.h>
+#include <pbl/i2c.h>
+#include <pbl/pmic.h>
+#include <linux/sizes.h>
+#include <mach/imx/atf.h>
+#include <mach/imx/xload.h>
+#include <mach/imx/esdctl.h>
+#include <mach/imx/generic.h>
+#include <mach/imx/imx8mp-regs.h>
+#include <mach/imx/iomux-mx8mp.h>
+#include <mach/imx/imx8m-ccm-regs.h>
+#include <mfd/pca9450.h>
+#include <soc/imx8m/ddr.h>
+#include <soc/fsl/fsl_udc.h>
+
+extern char __dtb_z_imx8mp_evk_start[];
+
+#define UART_PAD_CTRL   MUX_PAD_CTRL(MX8MP_PAD_CTL_DSE6 | \
+				     MX8MP_PAD_CTL_FSEL)
+
+#define I2C_PAD_CTRL	MUX_PAD_CTRL(MX8MP_PAD_CTL_DSE6 | \
+				     MX8MP_PAD_CTL_HYS | \
+				     MX8MP_PAD_CTL_PUE | \
+				     MX8MP_PAD_CTL_PE)
+
+static void setup_uart(void)
+{
+	void __iomem *uart = IOMEM(MX8M_UART2_BASE_ADDR);
+
+	imx8m_early_setup_uart_clock();
+
+	imx8mp_setup_pad(MX8MP_PAD_UART2_TXD__UART2_DCE_TX | UART_PAD_CTRL);
+	imx8mp_setup_pad(MX8MP_PAD_UART2_RXD__UART2_DCE_RX | UART_PAD_CTRL);
+	imx8m_uart_setup(uart);
+
+	pbl_set_putc(imx_uart_putc, uart);
+
+	putc_ll('>');
+}
+
+static struct pmic_config pca9450_cfg[] = {
+	/* BUCKxOUT_DVS0/1 control BUCK123 output */
+	{ PCA9450_BUCK123_DVS, 0x29 },
+	/*
+	 * increase VDD_SOC to typical value 0.95V before first
+	 * DRAM access, set DVS1 to 0.85v for suspend.
+	 * Enable DVS control through PMIC_STBY_REQ and
+	 * set B1_ENMODE=1 (ON by PMIC_ON_REQ=H)
+	 */
+	{ PCA9450_BUCK1OUT_DVS0, 0x1C },
+	{ PCA9450_BUCK1OUT_DVS1, 0x14 },
+	{ PCA9450_BUCK1CTRL, 0x59 },
+	/*
+	 * Increase VDD_ARM to 0.95V to avoid issues in case software after
+	 * Barebox switches to the OD ARM frequency without reprogramming the
+	 * PMIC first.
+	 */
+	{ PCA9450_BUCK2OUT_DVS0, 0x1C },
+	/* set WDOG_B_CFG to cold reset */
+	{ PCA9450_RESET_CTRL, 0xA1 },
+};
+
+static void power_init_board(void)
+{
+	struct pbl_i2c *i2c;
+
+	imx8mp_setup_pad(MX8MP_PAD_I2C1_SCL__I2C1_SCL | I2C_PAD_CTRL);
+	imx8mp_setup_pad(MX8MP_PAD_I2C1_SDA__I2C1_SDA | I2C_PAD_CTRL);
+
+	imx8m_ccgr_clock_enable(IMX8M_CCM_CCGR_I2C1);
+
+	i2c = imx8m_i2c_early_init(IOMEM(MX8MP_I2C1_BASE_ADDR));
+
+	pmic_configure(i2c, 0x25, pca9450_cfg, ARRAY_SIZE(pca9450_cfg));
+}
+
+extern struct dram_timing_info imx8mp_evk_dram_timing;
+
+static void start_atf(void)
+{
+	/*
+	 * If we are in EL3 we are running for the first time and need to
+	 * initialize the DRAM and run TF-A (BL31). The TF-A will then jump
+	 * to DRAM in EL2.
+	 */
+	if (current_el() != 3)
+		return;
+
+	imx8mp_early_clock_init();
+
+	power_init_board();
+
+	imx8mp_ddr_init(&imx8mp_evk_dram_timing, DRAM_TYPE_LPDDR4);
+
+	imx8mp_load_and_start_image_via_tfa();
+}
+
+/*
+ * Power-on execution flow of start_nxp_imx8mp_evk() might not be
+ * obvious for a very first read, so here's, hopefully helpful,
+ * summary:
+ *
+ * 1. MaskROM uploads PBL into OCRAM and that's where this function is
+ *    executed for the first time. At entry the exception level is EL3.
+ *
+ * 2. DDR is initialized and the image is loaded from storage into DRAM. The PBL
+ *    part is copied from OCRAM to the TF-A return address in DRAM.
+ *
+ * 3. TF-A is executed and exits into the PBL code in DRAM. TF-A has taken us
+ *    from EL3 to EL2.
+ *
+ * 4. Standard barebox boot flow continues
+ */
+static __noreturn noinline void nxp_imx8mp_evk_start(void)
+{
+	setup_uart();
+
+	start_atf();
+
+	/*
+	 * Standard entry we hit once we initialized both DDR and ATF
+	 */
+	imx8mp_barebox_entry(__dtb_z_imx8mp_evk_start);
+}
+
+ENTRY_FUNCTION(start_nxp_imx8mp_evk, r0, r1, r2)
+{
+	imx8mp_cpu_lowlevel_init();
+
+	relocate_to_current_adr();
+	setup_c();
+
+	nxp_imx8mp_evk_start();
+}