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/*
* Joshua Henderson <joshua.henderson@microchip.com>
* Copyright (C) 2015 Microchip Technology Inc. All rights reserved.
*
* This program is free software; you can distribute it and/or modify it
* under the terms of the GNU General Public License (Version 2) as
* published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*/
#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_nocache(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));
}
}
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