package/uboot-xburst/files/cpu/mips/jz_serial.c

   1 /*
   2  * Jz47xx UART support
   3  *
   4  * Hardcoded to UART 0 for now
   5  * Options also hardcoded to 8N1
   6  *
   7  *  Copyright (c) 2005
   8  *  Ingenic Semiconductor, <jlwei@ingenic.cn>
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License as
  12  * published by the Free Software Foundation; either version 2 of
  13  * the License, or (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  23  * MA 02111-1307 USA
  24  */
  25
  26 #include <config.h>
  27
  28 #if defined(CONFIG_JZ4740)
  29
  30 #include <common.h>
  31
  32 #include <asm/jz4740.h>
  33
  34 #undef UART_BASE
  35 #ifndef CONFIG_SYS_UART_BASE
  36 #define UART_BASE  UART0_BASE
  37 #else
  38 #define UART_BASE  CONFIG_SYS_UART_BASE
  39 #endif
  40
  41 /******************************************************************************
  42 *
  43 * serial_init - initialize a channel
  44 *
  45 * This routine initializes the number of data bits, parity
  46 * and set the selected baud rate. Interrupts are disabled.
  47 * Set the modem control signals if the option is selected.
  48 *
  49 * RETURNS: N/A
  50 */
  51
  52 int serial_init (void)
  53 {
  54 #if !defined(CONFIG_NAND_U_BOOT) || defined(CONFIG_NAND_SPL)
  55         volatile u8 *uart_fcr = (volatile u8 *)(UART_BASE + OFF_FCR);
  56         volatile u8 *uart_lcr = (volatile u8 *)(UART_BASE + OFF_LCR);
  57         volatile u8 *uart_ier = (volatile u8 *)(UART_BASE + OFF_IER);
  58         volatile u8 *uart_sircr = (volatile u8 *)(UART_BASE + OFF_SIRCR);
  59
  60         /* Disable port interrupts while changing hardware */
  61         *uart_ier = 0;
  62
  63         /* Disable UART unit function */
  64         *uart_fcr = ~UART_FCR_UUE;
  65
  66         /* Set both receiver and transmitter in UART mode (not SIR) */
  67         *uart_sircr = ~(SIRCR_RSIRE | SIRCR_TSIRE);
  68
  69         /* Set databits, stopbits and parity. (8-bit data, 1 stopbit, no parity) */
  70         *uart_lcr = UART_LCR_WLEN_8 | UART_LCR_STOP_1;
  71
  72         /* Set baud rate */
  73         serial_setbrg();
  74
  75         /* Enable UART unit, enable and clear FIFO */
  76         *uart_fcr = UART_FCR_UUE | UART_FCR_FE | UART_FCR_TFLS | UART_FCR_RFLS;
  77 #endif
  78         return 0;
  79 }
  80
  81 void serial_setbrg (void)
  82 {
  83         volatile u8 *uart_lcr = (volatile u8 *)(UART_BASE + OFF_LCR);
  84         volatile u8 *uart_dlhr = (volatile u8 *)(UART_BASE + OFF_DLHR);
  85         volatile u8 *uart_dllr = (volatile u8 *)(UART_BASE + OFF_DLLR);
  86         u32 baud_div, tmp;
  87
  88         baud_div = CONFIG_SYS_EXTAL / 16 / CONFIG_BAUDRATE;
  89
  90         tmp = *uart_lcr;
  91         tmp |= UART_LCR_DLAB;
  92         *uart_lcr = tmp;
  93
  94         *uart_dlhr = (baud_div >> 8) & 0xff;
  95         *uart_dllr = baud_div & 0xff;
  96
  97         tmp &= ~UART_LCR_DLAB;
  98         *uart_lcr = tmp;
  99 }
 100
 101 void serial_putc (const char c)
 102 {
 103         volatile u8 *uart_lsr = (volatile u8 *)(UART_BASE + OFF_LSR);
 104         volatile u8 *uart_tdr = (volatile u8 *)(UART_BASE + OFF_TDR);
 105
 106         if (c == '\n') serial_putc ('\r');
 107
 108         /* Wait for fifo to shift out some bytes */
 109         while ( !((*uart_lsr & (UART_LSR_TDRQ | UART_LSR_TEMT)) == 0x60) );
 110
 111         *uart_tdr = (u8)c;
 112 }
 113
 114 void serial_puts (const char *s)
 115 {
 116         while (*s) {
 117                 serial_putc (*s++);
 118         }
 119 }
 120
 121 int serial_getc (void)
 122 {
 123         volatile u8 *uart_rdr = (volatile u8 *)(UART_BASE + OFF_RDR);
 124
 125         while (!serial_tstc());
 126
 127         return *uart_rdr;
 128 }
 129
 130 int serial_tstc (void)
 131 {
 132         volatile u8 *uart_lsr = (volatile u8 *)(UART_BASE + OFF_LSR);
 133
 134         if (*uart_lsr & UART_LSR_DR) {
 135                 /* Data in rfifo */
 136                 return (1);
 137         }
 138         return 0;
 139 }
 140
 141 #endif