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