// SPDX-License-Identifier: GPL-2.0 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include extern char __dtb_imx8mm_evk_start[]; #define UART_PAD_CTRL MUX_PAD_CTRL(PAD_CTL_DSE_3P3V_45_OHM) static void setup_uart(void) { void __iomem *uart = IOMEM(MX8M_UART2_BASE_ADDR); imx8m_early_setup_uart_clock(); imx8mm_setup_pad(IMX8MM_PAD_UART2_TXD_UART2_TX | UART_PAD_CTRL); imx8m_uart_setup(uart); pbl_set_putc(imx_uart_putc, uart); putc_ll('>'); } static void pmic_reg_write(void *i2c, int reg, uint8_t val) { int ret; u8 buf[32]; struct i2c_msg msgs[] = { { .addr = 0x4b, .buf = buf, }, }; buf[0] = reg; buf[1] = val; msgs[0].len = 2; ret = i2c_fsl_xfer(i2c, msgs, ARRAY_SIZE(msgs)); if (ret != 1) pr_err("Failed to write to pmic\n"); } static int power_init_board(void) { void *i2c; imx8mm_setup_pad(IMX8MM_PAD_I2C1_SCL_I2C1_SCL); imx8mm_setup_pad(IMX8MM_PAD_I2C1_SDA_I2C1_SDA); imx8mm_early_clock_init(); imx8m_ccgr_clock_enable(IMX8M_CCM_CCGR_I2C1); i2c = imx8m_i2c_early_init(IOMEM(MX8MQ_I2C1_BASE_ADDR)); /* decrease RESET key long push time from the default 10s to 10ms */ pmic_reg_write(i2c, BD718XX_PWRONCONFIG1, 0x0); /* unlock the PMIC regs */ pmic_reg_write(i2c, BD718XX_REGLOCK, 0x1); /* increase VDD_SOC to typical value 0.85v before first DRAM access */ pmic_reg_write(i2c, BD718XX_BUCK1_VOLT_RUN, 0x0f); /* increase VDD_DRAM to 0.975v for 3Ghz DDR */ pmic_reg_write(i2c, BD718XX_1ST_NODVS_BUCK_VOLT, 0x83); /* lock the PMIC regs */ pmic_reg_write(i2c, BD718XX_REGLOCK, 0x11); return 0; } extern struct dram_timing_info imx8mm_evk_dram_timing; static void start_atf(void) { size_t bl31_size; const u8 *bl31; enum bootsource src; int instance; /* * 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; power_init_board(); imx8mm_ddr_init(&imx8mm_evk_dram_timing); imx8mm_get_boot_source(&src, &instance); switch (src) { case BOOTSOURCE_MMC: imx8m_esdhc_load_image(instance, false); break; case BOOTSOURCE_SERIAL: imx8mm_barebox_load_usb((void *)MX8M_ATF_BL33_BASE_ADDR); break; default: printf("Unhandled bootsource BOOTSOURCE_%d\n", src); hang(); } /* * On completion the TF-A will jump to MX8M_ATF_BL33_BASE_ADDR * in EL2. Copy the image there, but replace the PBL part of * that image with ourselves. On a high assurance boot only the * currently running code is validated and contains the checksum * for the piggy data, so we need to ensure that we are running * the same code in DRAM. */ memcpy((void *)MX8M_ATF_BL33_BASE_ADDR, __image_start, barebox_pbl_size); get_builtin_firmware(imx8mm_bl31_bin, &bl31, &bl31_size); imx8mm_atf_load_bl31(bl31, bl31_size); /* not reached */ } /* * Power-on execution flow of start_nxp_imx8mm_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_imx8mm_evk_start(void) { setup_uart(); start_atf(); /* * Standard entry we hit once we initialized both DDR and ATF */ imx8mm_barebox_entry(__dtb_imx8mm_evk_start); } ENTRY_FUNCTION(start_nxp_imx8mm_evk, r0, r1, r2) { void __iomem *ccm = IOMEM(MX8M_CCM_BASE_ADDR); writel(IMX8M_CCM_CCGR_SETTINGn_NEEDED(0), ccm + IMX8M_CCM_CCGRn_SET(IMX8M_CCM_CCGR_SCTR)); imx8mm_cpu_lowlevel_init(); relocate_to_current_adr(); setup_c(); nxp_imx8mm_evk_start(); }