162 lines
3.1 KiB
C
162 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Joshua Henderson <joshua.henderson@microchip.com>
|
|
* Copyright (C) 2015 Microchip Technology Inc. All rights reserved.
|
|
*/
|
|
#include <asm/mach-pic32/pic32.h>
|
|
#include <asm/fw/fw.h>
|
|
#include <asm/setup.h>
|
|
|
|
#include "pic32mzda.h"
|
|
#include "early_pin.h"
|
|
|
|
/* Default early console parameters */
|
|
#define EARLY_CONSOLE_PORT 1
|
|
#define EARLY_CONSOLE_BAUDRATE 115200
|
|
|
|
#define UART_ENABLE BIT(15)
|
|
#define UART_ENABLE_RX BIT(12)
|
|
#define UART_ENABLE_TX BIT(10)
|
|
#define UART_TX_FULL BIT(9)
|
|
|
|
/* UART1(x == 0) - UART6(x == 5) */
|
|
#define UART_BASE(x) ((x) * 0x0200)
|
|
#define U_MODE(x) UART_BASE(x)
|
|
#define U_STA(x) (UART_BASE(x) + 0x10)
|
|
#define U_TXR(x) (UART_BASE(x) + 0x20)
|
|
#define U_BRG(x) (UART_BASE(x) + 0x40)
|
|
|
|
static void __iomem *uart_base;
|
|
static int console_port = -1;
|
|
|
|
static int __init configure_uart_pins(int port)
|
|
{
|
|
switch (port) {
|
|
case 1:
|
|
pic32_pps_input(IN_FUNC_U2RX, IN_RPB0);
|
|
pic32_pps_output(OUT_FUNC_U2TX, OUT_RPG9);
|
|
break;
|
|
case 5:
|
|
pic32_pps_input(IN_FUNC_U6RX, IN_RPD0);
|
|
pic32_pps_output(OUT_FUNC_U6TX, OUT_RPB8);
|
|
break;
|
|
default:
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __init configure_uart(int port, int baud)
|
|
{
|
|
u32 pbclk;
|
|
|
|
pbclk = pic32_get_pbclk(2);
|
|
|
|
__raw_writel(0, uart_base + U_MODE(port));
|
|
__raw_writel(((pbclk / baud) / 16) - 1, uart_base + U_BRG(port));
|
|
__raw_writel(UART_ENABLE, uart_base + U_MODE(port));
|
|
__raw_writel(UART_ENABLE_TX | UART_ENABLE_RX,
|
|
uart_base + PIC32_SET(U_STA(port)));
|
|
}
|
|
|
|
static void __init setup_early_console(int port, int baud)
|
|
{
|
|
if (configure_uart_pins(port))
|
|
return;
|
|
|
|
console_port = port;
|
|
configure_uart(console_port, baud);
|
|
}
|
|
|
|
static char * __init pic32_getcmdline(void)
|
|
{
|
|
/*
|
|
* arch_mem_init() has not been called yet, so we don't have a real
|
|
* command line setup if using CONFIG_CMDLINE_BOOL.
|
|
*/
|
|
#ifdef CONFIG_CMDLINE_OVERRIDE
|
|
return CONFIG_CMDLINE;
|
|
#else
|
|
return fw_getcmdline();
|
|
#endif
|
|
}
|
|
|
|
static int __init get_port_from_cmdline(char *arch_cmdline)
|
|
{
|
|
char *s;
|
|
int port = -1;
|
|
|
|
if (!arch_cmdline || *arch_cmdline == '\0')
|
|
goto _out;
|
|
|
|
s = strstr(arch_cmdline, "earlyprintk=");
|
|
if (s) {
|
|
s = strstr(s, "ttyS");
|
|
if (s)
|
|
s += 4;
|
|
else
|
|
goto _out;
|
|
|
|
port = (*s) - '0';
|
|
}
|
|
|
|
_out:
|
|
return port;
|
|
}
|
|
|
|
static int __init get_baud_from_cmdline(char *arch_cmdline)
|
|
{
|
|
char *s;
|
|
int baud = -1;
|
|
|
|
if (!arch_cmdline || *arch_cmdline == '\0')
|
|
goto _out;
|
|
|
|
s = strstr(arch_cmdline, "earlyprintk=");
|
|
if (s) {
|
|
s = strstr(s, "ttyS");
|
|
if (s)
|
|
s += 6;
|
|
else
|
|
goto _out;
|
|
|
|
baud = 0;
|
|
while (*s >= '0' && *s <= '9')
|
|
baud = baud * 10 + *s++ - '0';
|
|
}
|
|
|
|
_out:
|
|
return baud;
|
|
}
|
|
|
|
void __init fw_init_early_console(void)
|
|
{
|
|
char *arch_cmdline = pic32_getcmdline();
|
|
int baud, port;
|
|
|
|
uart_base = ioremap(PIC32_BASE_UART, 0xc00);
|
|
|
|
baud = get_baud_from_cmdline(arch_cmdline);
|
|
port = get_port_from_cmdline(arch_cmdline);
|
|
|
|
if (port == -1)
|
|
port = EARLY_CONSOLE_PORT;
|
|
|
|
if (baud == -1)
|
|
baud = EARLY_CONSOLE_BAUDRATE;
|
|
|
|
setup_early_console(port, baud);
|
|
}
|
|
|
|
void prom_putchar(char c)
|
|
{
|
|
if (console_port >= 0) {
|
|
while (__raw_readl(
|
|
uart_base + U_STA(console_port)) & UART_TX_FULL)
|
|
;
|
|
|
|
__raw_writel(c, uart_base + U_TXR(console_port));
|
|
}
|
|
}
|