freebsd-dev/sys/arm/amlogic/aml8726/aml8726_uart_console.c

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/*-
* Copyright 2013-2015 John Wehle <john@feith.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* Amlogic aml8726 UART console driver.
*
* This is only necessary to use when debugging early boot code.
* The standard uart driver is available for use later in the boot.
*
* It's assumed the SoC uart is mapped into AML_UART_KVM_BASE meaning
* when using EARLY_PRINTF you'll need to define SOCDEV_VA to be
* 0xd8100000 and SOCDEV_PA to be 0xc8100000 in your config file.
*/
#include "opt_global.h"
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/cons.h>
#include <sys/consio.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <machine/bus.h>
#include <machine/cpu.h>
#include <arm/amlogic/aml8726/aml8726_machdep.h>
#include <arm/amlogic/aml8726/aml8726_uart.h>
#define AML_UART_KVM_BASE (aml8726_aobus_kva_base + 0x130 * 4)
static uint32_t
ub_getreg(uint32_t off)
{
return *((volatile uint32_t *)(AML_UART_KVM_BASE + off));
}
static void
ub_setreg(uint32_t off, uint32_t val)
{
*((volatile uint32_t *)(AML_UART_KVM_BASE + off)) = val;
}
static void
uart_cnprobe(struct consdev *cp)
{
sprintf(cp->cn_name, "uart");
cp->cn_pri = CN_REMOTE;
}
static void
uart_cngrab(struct consdev *cp)
{
}
static void
uart_cnungrab(struct consdev *cp)
{
}
static void
uart_cninit(struct consdev *cp)
{
uint32_t cr;
uint32_t mr;
#ifdef EARLY_PRINTF
if (early_putc != NULL) {
printf("Early printf yielding control to the real console.\n");
early_putc = NULL;
}
/*
* Give pending characters a chance to drain.
*/
DELAY(4000);
#endif
cr = ub_getreg(AML_UART_CONTROL_REG);
/* Disable all interrupt sources. */
cr &= ~(AML_UART_CONTROL_TX_INT_EN | AML_UART_CONTROL_RX_INT_EN);
/* Reset the transmitter and receiver. */
cr |= (AML_UART_CONTROL_TX_RST | AML_UART_CONTROL_RX_RST);
/* Use two wire mode. */
cr |= AML_UART_CONTROL_TWO_WIRE_EN;
/* Enable the transmitter and receiver. */
cr |= (AML_UART_CONTROL_TX_EN | AML_UART_CONTROL_RX_EN);
ub_setreg(AML_UART_CONTROL_REG, cr);
/* Clear RX FIFO level for generating interrupts. */
mr = ub_getreg(AML_UART_MISC_REG);
mr &= ~AML_UART_MISC_RECV_IRQ_CNT_MASK;
ub_setreg(AML_UART_MISC_REG, mr);
/* Ensure the reset bits are clear. */
cr &= ~(AML_UART_CONTROL_TX_RST | AML_UART_CONTROL_RX_RST);
ub_setreg(AML_UART_CONTROL_REG, cr);
}
static void
uart_cnterm(struct consdev * cp)
{
}
static void
uart_cnputc(struct consdev *cp, int c)
{
while ((ub_getreg(AML_UART_STATUS_REG) &
AML_UART_STATUS_TX_FIFO_FULL) != 0)
cpu_spinwait();
ub_setreg(AML_UART_WFIFO_REG, c);
}
static int
uart_cngetc(struct consdev * cp)
{
int c;
if ((ub_getreg(AML_UART_STATUS_REG) &
AML_UART_STATUS_RX_FIFO_EMPTY) != 0)
return (-1);
c = ub_getreg(AML_UART_RFIFO_REG) & 0xff;
return (c);
}
CONSOLE_DRIVER(uart);
#ifdef EARLY_PRINTF
#if !(defined(SOCDEV_PA) && defined(SOCDEV_VA))
#error SOCDEV_PA and SOCDEV_VA must be defined.
#endif
static void
eputc(int c)
{
if (c == '\n')
eputc('\r');
uart_cnputc(NULL, c);
}
early_putc_t *early_putc = eputc;
#endif