LXR uboot/arch/sparc/cpu/leon3/serial.c

   1/* GRLIB APBUART Serial controller driver
   2 *
   3 * (C) Copyright 2007
   4 * Daniel Hellstrom, Gaisler Research, daniel@gaisler.com.
   5 *
   6 * See file CREDITS for list of people who contributed to this
   7 * project.
   8 *
   9 * This program is free software; you can redistribute it and/or
  10 * modify it under the terms of the GNU General Public License as
  11 * published by the Free Software Foundation; either version 2 of
  12 * the License, or (at your option) any later version.
  13 *
  14 * This program is distributed in the hope that it will be useful,
  15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 * GNU General Public License for more details.
  18 *
  19 * You should have received a copy of the GNU General Public License
  20 * along with this program; if not, write to the Free Software
  21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  22 * MA 02111-1307 USA
  23 *
  24 */
  25
  26#include <common.h>
  27#include <asm/processor.h>
  28#include <asm/leon.h>
  29#include <ambapp.h>
  30#include <serial.h>
  31#include <linux/compiler.h>
  32
  33DECLARE_GLOBAL_DATA_PTR;
  34
  35ambapp_dev_apbuart *leon3_apbuart = NULL;
  36
  37static int leon3_serial_init(void)
  38{
  39        ambapp_apbdev apbdev;
  40        unsigned int tmp;
  41
  42        /* find UART */
  43        if (ambapp_apb_first(VENDOR_GAISLER, GAISLER_APBUART, &apbdev) == 1) {
  44
  45                leon3_apbuart = (ambapp_dev_apbuart *) apbdev.address;
  46
  47                /* found apbuart, let's init...
  48                 *
  49                 * Set scaler / baud rate
  50                 *
  51                 * Receiver & transmitter enable
  52                 */
  53                leon3_apbuart->scaler = CONFIG_SYS_GRLIB_APBUART_SCALER;
  54
  55                /* Let bit 11 be unchanged (debug bit for GRMON) */
  56                tmp = READ_WORD(leon3_apbuart->ctrl);
  57
  58                leon3_apbuart->ctrl = ((tmp & LEON_REG_UART_CTRL_DBG) |
  59                                       LEON_REG_UART_CTRL_RE |
  60                                       LEON_REG_UART_CTRL_TE);
  61
  62                return 0;
  63        }
  64        return -1;              /* didn't find hardware */
  65}
  66
  67static void leon3_serial_putc_raw(const char c)
  68{
  69        if (!leon3_apbuart)
  70                return;
  71
  72        /* Wait for last character to go. */
  73        while (!(READ_WORD(leon3_apbuart->status) & LEON_REG_UART_STATUS_THE)) ;
  74
  75        /* Send data */
  76        leon3_apbuart->data = c;
  77
  78#ifdef LEON_DEBUG
  79        /* Wait for data to be sent */
  80        while (!(READ_WORD(leon3_apbuart->status) & LEON_REG_UART_STATUS_TSE)) ;
  81#endif
  82}
  83
  84static void leon3_serial_putc(const char c)
  85{
  86        if (c == '\n')
  87                leon3_serial_putc_raw('\r');
  88
  89        leon3_serial_putc_raw(c);
  90}
  91
  92static int leon3_serial_getc(void)
  93{
  94        if (!leon3_apbuart)
  95                return 0;
  96
  97        /* Wait for a character to arrive. */
  98        while (!(READ_WORD(leon3_apbuart->status) & LEON_REG_UART_STATUS_DR)) ;
  99
 100        /* read data */
 101        return READ_WORD(leon3_apbuart->data);
 102}
 103
 104static int leon3_serial_tstc(void)
 105{
 106        if (leon3_apbuart)
 107                return (READ_WORD(leon3_apbuart->status) &
 108                        LEON_REG_UART_STATUS_DR);
 109        return 0;
 110}
 111
 112/* set baud rate for uart */
 113static void leon3_serial_setbrg(void)
 114{
 115        /* update baud rate settings, read it from gd->baudrate */
 116        unsigned int scaler;
 117        if (leon3_apbuart && (gd->baudrate > 0)) {
 118                scaler =
 119                    (((CONFIG_SYS_CLK_FREQ * 10) / (gd->baudrate * 8)) -
 120                     5) / 10;
 121                leon3_apbuart->scaler = scaler;
 122        }
 123        return;
 124}
 125
 126static struct serial_device leon3_serial_drv = {
 127        .name   = "leon3_serial",
 128        .start  = leon3_serial_init,
 129        .stop   = NULL,
 130        .setbrg = leon3_serial_setbrg,
 131        .putc   = leon3_serial_putc,
 132        .puts   = default_serial_puts,
 133        .getc   = leon3_serial_getc,
 134        .tstc   = leon3_serial_tstc,
 135};
 136
 137void leon3_serial_initialize(void)
 138{
 139        serial_register(&leon3_serial_drv);
 140}
 141
 142__weak struct serial_device *default_serial_console(void)
 143{
 144        return &leon3_serial_drv;
 145}
 146