1*91f16700Schasinglulu /* 2*91f16700Schasinglulu * Copyright (c) 2023, Pengutronix. All rights reserved. 3*91f16700Schasinglulu * 4*91f16700Schasinglulu * SPDX-License-Identifier: BSD-3-Clause 5*91f16700Schasinglulu */ 6*91f16700Schasinglulu 7*91f16700Schasinglulu #include <lib/mmio.h> 8*91f16700Schasinglulu #include <platform_def.h> 9*91f16700Schasinglulu 10*91f16700Schasinglulu #define UCR1 0x80 11*91f16700Schasinglulu #define UCR1_UARTEN BIT(0) 12*91f16700Schasinglulu #define DOMAIN0_RUNNING(d) (((d) & 0x3) != 0) 13*91f16700Schasinglulu 14*91f16700Schasinglulu static struct imx_uart { 15*91f16700Schasinglulu unsigned int ccm_reg; 16*91f16700Schasinglulu unsigned int uart_base; 17*91f16700Schasinglulu } imx8m_uart_info[] = { 18*91f16700Schasinglulu { /* UART 1 */ 19*91f16700Schasinglulu .ccm_reg = 0x4490, 20*91f16700Schasinglulu .uart_base = 0x30860000, 21*91f16700Schasinglulu }, { /* UART 2 */ 22*91f16700Schasinglulu .ccm_reg = 0x44a0, 23*91f16700Schasinglulu .uart_base = 0x30890000, 24*91f16700Schasinglulu }, { /* UART 3 */ 25*91f16700Schasinglulu .ccm_reg = 0x44b0, 26*91f16700Schasinglulu .uart_base = 0x30880000, 27*91f16700Schasinglulu }, { /* UART 4 */ 28*91f16700Schasinglulu .ccm_reg = 0x44c0, 29*91f16700Schasinglulu .uart_base = 0x30a60000, 30*91f16700Schasinglulu } 31*91f16700Schasinglulu }; 32*91f16700Schasinglulu 33*91f16700Schasinglulu unsigned int imx8m_uart_get_base(void) 34*91f16700Schasinglulu { 35*91f16700Schasinglulu unsigned int i; 36*91f16700Schasinglulu 37*91f16700Schasinglulu for (i = 0; i < ARRAY_SIZE(imx8m_uart_info); i++) { 38*91f16700Schasinglulu uint32_t val; 39*91f16700Schasinglulu 40*91f16700Schasinglulu /* 41*91f16700Schasinglulu * At least check that the clock-gate is ungated before we 42*91f16700Schasinglulu * access the UART register. 43*91f16700Schasinglulu */ 44*91f16700Schasinglulu val = mmio_read_32(IMX_CCM_BASE + imx8m_uart_info[i].ccm_reg); 45*91f16700Schasinglulu if (DOMAIN0_RUNNING(val)) { 46*91f16700Schasinglulu val = mmio_read_32(imx8m_uart_info[i].uart_base + UCR1); 47*91f16700Schasinglulu if (val & UCR1_UARTEN) { 48*91f16700Schasinglulu return imx8m_uart_info[i].uart_base; 49*91f16700Schasinglulu } 50*91f16700Schasinglulu } 51*91f16700Schasinglulu } 52*91f16700Schasinglulu 53*91f16700Schasinglulu /* 54*91f16700Schasinglulu * We should return an error and inform the user but we can't do it 55*91f16700Schasinglulu * this early. 56*91f16700Schasinglulu */ 57*91f16700Schasinglulu return 0; 58*91f16700Schasinglulu } 59