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scoutos / prex-0.9.0 / bsp / boot / arm / integrator / debug.c @ 03e9c04a

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/*-
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 * Copyright (c) 2008-2009, Kohsuke Ohtani
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 * All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 * 1. Redistributions of source code must retain the above copyright
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 *    notice, this list of conditions and the following disclaimer.
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 * 2. Redistributions in binary form must reproduce the above copyright
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 *    notice, this list of conditions and the following disclaimer in the
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 *    documentation and/or other materials provided with the distribution.
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 * 3. Neither the name of the author nor the names of any co-contributors
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 *    may be used to endorse or promote products derived from this software
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 *    without specific prior written permission.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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 * SUCH DAMAGE.
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 */
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#include <sys/param.h>
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#include <boot.h>
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#define UART_BASE        0x16000000
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#define UART_CLK        14745600
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#define BAUD_RATE        115200
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/* UART Registers */
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#define UART_DR                (*(volatile uint32_t *)(UART_BASE + 0x00))
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#define UART_RSR        (*(volatile uint32_t *)(UART_BASE + 0x04))
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#define UART_ECR        (*(volatile uint32_t *)(UART_BASE + 0x04))
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#define UART_FR                (*(volatile uint32_t *)(UART_BASE + 0x18))
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#define UART_IBRD        (*(volatile uint32_t *)(UART_BASE + 0x24))
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#define UART_FBRD        (*(volatile uint32_t *)(UART_BASE + 0x28))
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#define UART_LCRH        (*(volatile uint32_t *)(UART_BASE + 0x2c))
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#define UART_CR                (*(volatile uint32_t *)(UART_BASE + 0x30))
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#define UART_IMSC        (*(volatile uint32_t *)(UART_BASE + 0x38))
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#define UART_MIS        (*(volatile uint32_t *)(UART_BASE + 0x40))
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#define UART_ICR        (*(volatile uint32_t *)(UART_BASE + 0x44))
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/* Flag register */
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#define FR_RXFE                0x10        /* Receive FIFO empty */
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#define FR_TXFF                0x20        /* Transmit FIFO full */
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/* Masked interrupt status register */
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#define MIS_RX                0x10        /* Receive interrupt */
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#define MIS_TX                0x20        /* Transmit interrupt */
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/* Interrupt clear register */
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#define ICR_RX                0x10        /* Clear receive interrupt */
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#define ICR_TX                0x20        /* Clear transmit interrupt */
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/* Line control register (High) */
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#define LCRH_WLEN8        0x60        /* 8 bits */
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#define LCRH_FEN        0x10        /* Enable FIFO */
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/* Control register */
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#define CR_UARTEN        0x0001        /* UART enable */
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#define CR_TXE                0x0100        /* Transmit enable */
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#define CR_RXE                0x0200        /* Receive enable */
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/* Interrupt mask set/clear register */
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#define IMSC_RX                0x10        /* Receive interrupt mask */
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#define IMSC_TX                0x20        /* Transmit interrupt mask */
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/*
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 * Print one chracter
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 */
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void
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debug_putc(int c)
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{
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#if defined(DEBUG) && defined(CONFIG_DIAG_SERIAL)
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        while (UART_FR & FR_TXFF)
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                ;
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        UART_DR = c;
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#endif
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}
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/*
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 * Initialize debug port.
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 */
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void
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debug_init(void)
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{
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#if defined(DEBUG) && defined(CONFIG_DIAG_SERIAL)
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        unsigned int divider;
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        unsigned int remainder;
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        unsigned int fraction;
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        UART_CR = 0x0;                /* Disable everything */
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        UART_ICR = 0x07ff;        /* Clear all interrupt status */
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        /*
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         * Set baud rate:
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         * IBRD = UART_CLK / (16 * BAUD_RATE)
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         * FBRD = ROUND((64 * MOD(UART_CLK,(16 * BAUD_RATE))) / (16 * BAUD_RATE))
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         */
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        divider = UART_CLK / (16 * BAUD_RATE);
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        remainder = UART_CLK % (16 * BAUD_RATE);
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        fraction = (8 * remainder / BAUD_RATE) >> 1;
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        fraction += (8 * remainder / BAUD_RATE) & 1;
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        UART_IBRD = divider;
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        UART_FBRD = fraction;
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        UART_LCRH = (LCRH_WLEN8 | LCRH_FEN);        /* N, 8, 1, FIFO enable */
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        UART_CR = (CR_RXE | CR_TXE | CR_UARTEN);        /* Enable UART */
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#endif
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}