xref: /aosp_15_r20/external/coreboot/src/ec/kontron/kempld/early_kempld.c (revision b9411a12aaaa7e1e6a6fb7c5e057f44ee179a49c) 
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 
3 #include <stdint.h>
4 #include <arch/io.h>
5 #include <delay.h>
6 
7 #include "chip.h"
8 #include "kempld.h"
9 #include "kempld_internal.h"
10 
kempld_write8(const uint8_t addr,const uint8_t data)11 void kempld_write8(const uint8_t addr, const uint8_t data)
12 {
13 	outb(addr, KEMPLD_IDX);
14 	outb(data, KEMPLD_DAT);
15 }
16 
kempld_read8(const uint8_t addr)17 uint8_t kempld_read8(const uint8_t addr)
18 {
19 	outb(addr, KEMPLD_IDX);
20 	return inb(KEMPLD_DAT);
21 }
22 
kempld_get_mutex(int timeout_ms)23 int kempld_get_mutex(int timeout_ms)
24 {
25 	while (inb(KEMPLD_IDX) & KEMPLD_MUTEX_KEY && timeout_ms--)
26 		mdelay(1);
27 	return timeout_ms;
28 }
29 
kempld_release_mutex(void)30 void kempld_release_mutex(void)
31 {
32 	outb(KEMPLD_MUTEX_KEY, KEMPLD_IDX);
33 }
34 
kempld_enable_uart_for_console(void)35 void kempld_enable_uart_for_console(void)
36 {
37 	if (!CONFIG(CONSOLE_SERIAL))
38 		return;
39 
40 	if (kempld_get_mutex(100) < 0)
41 		return;
42 
43 	switch (CONFIG_UART_FOR_CONSOLE) {
44 	case 0:
45 		kempld_write8(KEMPLD_UART_0,
46 			      KEMPLD_UART_ENABLE | KEMPLD_UART_3F8 << KEMPLD_UART_IO_SHIFT);
47 		break;
48 	case 1:
49 		kempld_write8(KEMPLD_UART_1,
50 			      KEMPLD_UART_ENABLE | KEMPLD_UART_2F8 << KEMPLD_UART_IO_SHIFT);
51 		break;
52 	default:
53 		break;
54 	}
55 
56 	kempld_release_mutex();
57 }
58