1 /*
2 * Copyright 2014, General Dynamics C4 Systems
3 *
4 * SPDX-License-Identifier: GPL-2.0-only
5 */
6
7 #include <config.h>
8 #include <arch/kernel/boot_sys.h>
9 #include <arch/model/statedata.h>
10 #include <machine/io.h>
11 #include <plat/machine/io.h>
12 #include <drivers/uart.h>
13
14 #if defined(CONFIG_DEBUG_BUILD) || defined(CONFIG_PRINTING)
serial_init(uint16_t port)15 void serial_init(uint16_t port)
16 {
17 while (!(in8(port + 5) & 0x60)); /* wait until not busy */
18
19 out8(port + 1, 0x00); /* disable generating interrupts */
20 out8(port + 3, 0x80); /* line control register: command: set divisor */
21 out8(port, 0x01); /* set low byte of divisor to 0x01 = 115200 baud */
22 out8(port + 1, 0x00); /* set high byte of divisor to 0x00 */
23 out8(port + 3, 0x03); /* line control register: set 8 bit, no parity, 1 stop bit */
24 out8(port + 4, 0x0b); /* modem control register: set DTR/RTS/OUT2 */
25
26 in8(port); /* clear receiver port */
27 in8(port + 5); /* clear line status port */
28 in8(port + 6); /* clear modem status port */
29 }
30 #endif /* defined(CONFIG_DEBUG_BUILD) || defined(CONFIG_PRINTING) */
31
32 #ifdef CONFIG_PRINTING
33
34 /* there is no UART driver at drivers/serial/... for the pc99 platform, but we
35 * implement parts of the API here, so we can reuse the generic code.
36 */
uart_drv_putchar(unsigned char c)37 void uart_drv_putchar(
38 unsigned char c)
39 {
40 while (x86KSdebugPort && (in8(x86KSdebugPort + 5) & 0x20) == 0);
41 out8(x86KSdebugPort, c);
42 }
43
kernel_putDebugChar(unsigned char c)44 void kernel_putDebugChar(unsigned char c)
45 {
46 /* this will take care of CR/LF handling and call uart_drv_putchar() */
47 uart_console_putchar(c);
48 }
49
50 #endif /* CONFIG_PRINTING */
51
52 #ifdef CONFIG_DEBUG_BUILD
kernel_getDebugChar(void)53 unsigned char kernel_getDebugChar(void)
54 {
55 while ((in8(x86KSdebugPort + 5) & 1) == 0);
56 return in8(x86KSdebugPort);
57 }
58 #endif /* CONFIG_DEBUG_BUILD */
59