1 /*
2  * Copyright (c) 2019-2020, Socionext Inc. All rights reserved.
3  *
4  * SPDX-License-Identifier: BSD-3-Clause
5  */
6 
7 #include <assert.h>
8 
9 #include <drivers/console.h>
10 #include <errno.h>
11 #include <lib/mmio.h>
12 #include <plat/common/platform.h>
13 
14 #include "uniphier.h"
15 #include "uniphier_console.h"
16 
17 #define UNIPHIER_UART_OFFSET	0x100
18 #define UNIPHIER_UART_NR_PORTS	4
19 
20 /* These callbacks are implemented in assembly to use crash_console_helpers.S */
21 int uniphier_console_putc(int character, struct console *console);
22 int uniphier_console_getc(struct console *console);
23 void uniphier_console_flush(struct console *console);
24 
25 static console_t uniphier_console = {
26 	.flags = CONSOLE_FLAG_BOOT |
27 #if DEBUG
28 		 CONSOLE_FLAG_RUNTIME |
29 #endif
30 		 CONSOLE_FLAG_CRASH |
31 		 CONSOLE_FLAG_TRANSLATE_CRLF,
32 	.putc = uniphier_console_putc,
33 #if ENABLE_CONSOLE_GETC
34 	.getc = uniphier_console_getc,
35 #endif
36 	.flush = uniphier_console_flush,
37 };
38 
39 static const uintptr_t uniphier_uart_base[] = {
40 	[UNIPHIER_SOC_LD11] = 0x54006800,
41 	[UNIPHIER_SOC_LD20] = 0x54006800,
42 	[UNIPHIER_SOC_PXS3] = 0x54006800,
43 };
44 
45 /*
46  * There are 4 UART ports available on this platform. By default, we want to
47  * use the same one as used in the previous firmware stage.
48  */
uniphier_console_get_base(unsigned int soc)49 static uintptr_t uniphier_console_get_base(unsigned int soc)
50 {
51 	uintptr_t base, end;
52 	uint32_t div;
53 
54 	assert(soc < ARRAY_SIZE(uniphier_uart_base));
55 	base = uniphier_uart_base[soc];
56 	end = base + UNIPHIER_UART_OFFSET * UNIPHIER_UART_NR_PORTS;
57 
58 	while (base < end) {
59 		div = mmio_read_32(base + UNIPHIER_UART_DLR);
60 		if (div)
61 			return base;
62 		base += UNIPHIER_UART_OFFSET;
63 	}
64 
65 	return 0;
66 }
67 
uniphier_console_init(uintptr_t base)68 static void uniphier_console_init(uintptr_t base)
69 {
70 	mmio_write_32(base + UNIPHIER_UART_FCR, UNIPHIER_UART_FCR_ENABLE_FIFO);
71 	mmio_write_32(base + UNIPHIER_UART_LCR_MCR,
72 		      UNIPHIER_UART_LCR_WLEN8 << 8);
73 }
74 
uniphier_console_setup(unsigned int soc)75 void uniphier_console_setup(unsigned int soc)
76 {
77 	uintptr_t base;
78 
79 	base = uniphier_console_get_base(soc);
80 	if (!base)
81 		plat_error_handler(-EINVAL);
82 
83 	uniphier_console.base = base;
84 	console_register(&uniphier_console);
85 
86 	/*
87 	 * The hardware might be still printing characters queued up in the
88 	 * previous firmware stage. Make sure the transmitter is empty before
89 	 * any initialization. Otherwise, the console might get corrupted.
90 	 */
91 	console_flush();
92 
93 	uniphier_console_init(base);
94 }
95