LXR uboot/drivers/serial/atmel

   1/*
   2 * Copyright (C) 2004-2006 Atmel Corporation
   3 *
   4 * Modified to support C structur SoC access by
   5 * Andreas Bießmann <biessmann@corscience.de>
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License as published by
   9 * the Free Software Foundation; either version 2 of the License, or
  10 * (at your option) any later version.
  11 *
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 *
  17 * You should have received a copy of the GNU General Public License
  18 * along with this program; if not, write to the Free Software
  19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20 */
  21#include <common.h>
  22#include <watchdog.h>
  23
  24#include <asm/io.h>
  25#include <asm/arch/clk.h>
  26#include <asm/arch/hardware.h>
  27
  28#include "atmel_usart.h"
  29
  30DECLARE_GLOBAL_DATA_PTR;
  31
  32void serial_setbrg(void)
  33{
  34        atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_USART_BASE;
  35        unsigned long divisor;
  36        unsigned long usart_hz;
  37
  38        /*
  39         *              Master Clock
  40         * Baud Rate = --------------
  41         *                16 * CD
  42         */
  43        usart_hz = get_usart_clk_rate(CONFIG_USART_ID);
  44        divisor = (usart_hz / 16 + gd->baudrate / 2) / gd->baudrate;
  45        writel(USART3_BF(CD, divisor), &usart->brgr);
  46}
  47
  48int serial_init(void)
  49{
  50        atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_USART_BASE;
  51
  52        writel(USART3_BIT(RSTRX) | USART3_BIT(RSTTX), &usart->cr);
  53
  54        serial_setbrg();
  55
  56        writel(USART3_BIT(RXEN) | USART3_BIT(TXEN), &usart->cr);
  57        writel((USART3_BF(USART_MODE, USART3_USART_MODE_NORMAL)
  58                           | USART3_BF(USCLKS, USART3_USCLKS_MCK)
  59                           | USART3_BF(CHRL, USART3_CHRL_8)
  60                           | USART3_BF(PAR, USART3_PAR_NONE)
  61                           | USART3_BF(NBSTOP, USART3_NBSTOP_1)),
  62                           &usart->mr);
  63
  64        return 0;
  65}
  66
  67void serial_putc(char c)
  68{
  69        atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_USART_BASE;
  70
  71        if (c == '\n')
  72                serial_putc('\r');
  73
  74        while (!(readl(&usart->csr) & USART3_BIT(TXRDY)));
  75        writel(c, &usart->thr);
  76}
  77
  78void serial_puts(const char *s)
  79{
  80        while (*s)
  81                serial_putc(*s++);
  82}
  83
  84int serial_getc(void)
  85{
  86        atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_USART_BASE;
  87
  88        while (!(readl(&usart->csr) & USART3_BIT(RXRDY)))
  89                 WATCHDOG_RESET();
  90        return readl(&usart->rhr);
  91}
  92
  93int serial_tstc(void)
  94{
  95        atmel_usart3_t *usart = (atmel_usart3_t *)CONFIG_USART_BASE;
  96        return (readl(&usart->csr) & USART3_BIT(RXRDY)) != 0;
  97}
  98