cpu/mpc512x/serial.c

   1 /*
   2  * (C) Copyright 2000 - 2007
   3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4  *
   5  * See file CREDITS for list of people who contributed to this
   6  * project.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation; either version 2 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21  * MA 02111-1307 USA
  22  *
  23  * Based ont the MPC5200 PSC driver.
  24  * Adapted for MPC512x by Jan Wrobel <wrr@semihalf.com>
  25  */
  26
  27 /*
  28  * Minimal serial functions needed to use one of the PSC ports
  29  * as serial console interface.
  30  */
  31
  32 #include <common.h>
  33
  34 DECLARE_GLOBAL_DATA_PTR;
  35
  36 #if defined(CONFIG_PSC_CONSOLE)
  37
  38 static void fifo_init (volatile psc512x_t *psc)
  39 {
  40         volatile immap_t *im = (immap_t *) CONFIG_SYS_IMMR;
  41
  42         /* reset Rx & Tx fifo slice */
  43         psc->rfcmd = PSC_FIFO_RESET_SLICE;
  44         psc->tfcmd = PSC_FIFO_RESET_SLICE;
  45
  46         /* disable Tx & Rx FIFO interrupts */
  47         psc->rfintmask = 0;
  48         psc->tfintmask = 0;
  49
  50         psc->tfsize = CONSOLE_FIFO_TX_SIZE | (CONSOLE_FIFO_TX_ADDR << 16);
  51         psc->rfsize = CONSOLE_FIFO_RX_SIZE | (CONSOLE_FIFO_RX_ADDR << 16);
  52
  53         /* enable Tx & Rx FIFO slice */
  54         psc->rfcmd = PSC_FIFO_ENABLE_SLICE;
  55         psc->tfcmd = PSC_FIFO_ENABLE_SLICE;
  56
  57         im->fifoc.fifoc_cmd = FIFOC_DISABLE_CLOCK_GATE;
  58         __asm__ volatile ("sync");
  59 }
  60
  61 int serial_init(void)
  62 {
  63         volatile immap_t *im = (immap_t *) CONFIG_SYS_IMMR;
  64         volatile psc512x_t *psc = (psc512x_t *) &im->psc[CONFIG_PSC_CONSOLE];
  65         unsigned long baseclk;
  66         int div;
  67
  68         fifo_init (psc);
  69
  70         /* set MR register to point to MR1 */
  71         psc->command = PSC_SEL_MODE_REG_1;
  72
  73         /* disable Tx/Rx */
  74         psc->command = PSC_TX_DISABLE | PSC_RX_DISABLE;
  75
  76         /* choose the prescaler by 16 for the Tx/Rx clock generation */
  77         psc->psc_clock_select =  0xdd00;
  78
  79         /* switch to UART mode */
  80         psc->sicr = 0;
  81
  82         /* mode register points to mr1 */
  83         /* configure parity, bit length and so on in mode register 1*/
  84         psc->mode = PSC_MODE_8_BITS | PSC_MODE_PARNONE;
  85         /* now, mode register points to mr2 */
  86         psc->mode = PSC_MODE_1_STOPBIT;
  87
  88         /* calculate dividor for setting PSC CTUR and CTLR registers */
  89         baseclk = (gd->ips_clk + 8) / 16;
  90         div = (baseclk + (gd->baudrate / 2)) / gd->baudrate;
  91
  92         psc->ctur = (div >> 8) & 0xff;
  93         /* set baudrate */
  94         psc->ctlr = div & 0xff;
  95
  96         /* disable all interrupts */
  97         psc->psc_imr = 0;
  98
  99         /* reset and enable Rx/Tx */
 100         psc->command = PSC_RST_RX;
 101         psc->command = PSC_RST_TX;
 102         psc->command = PSC_RX_ENABLE | PSC_TX_ENABLE;
 103
 104         return 0;
 105 }
 106
 107 void serial_putc (const char c)
 108 {
 109         volatile immap_t *im = (immap_t *)CONFIG_SYS_IMMR;
 110         volatile psc512x_t *psc = (psc512x_t *) &im->psc[CONFIG_PSC_CONSOLE];
 111
 112         if (c == '\n')
 113                 serial_putc ('\r');
 114
 115         /* Wait for last character to go. */
 116         while (!(psc->psc_status & PSC_SR_TXEMP))
 117                 ;
 118
 119         psc->tfdata_8 = c;
 120 }
 121
 122 void serial_putc_raw (const char c)
 123 {
 124         volatile immap_t *im = (immap_t *) CONFIG_SYS_IMMR;
 125         volatile psc512x_t *psc = (psc512x_t *) &im->psc[CONFIG_PSC_CONSOLE];
 126
 127         /* Wait for last character to go. */
 128         while (!(psc->psc_status & PSC_SR_TXEMP))
 129                 ;
 130
 131         psc->tfdata_8 = c;
 132 }
 133
 134
 135 void serial_puts (const char *s)
 136 {
 137         while (*s) {
 138                 serial_putc (*s++);
 139         }
 140 }
 141
 142 int serial_getc (void)
 143 {
 144         volatile immap_t *im = (immap_t *) CONFIG_SYS_IMMR;
 145         volatile psc512x_t *psc = (psc512x_t *) &im->psc[CONFIG_PSC_CONSOLE];
 146
 147         /* Wait for a character to arrive. */
 148         while (psc->rfstat & PSC_FIFO_EMPTY)
 149                 ;
 150
 151         return psc->rfdata_8;
 152 }
 153
 154 int serial_tstc (void)
 155 {
 156         volatile immap_t *im = (immap_t *) CONFIG_SYS_IMMR;
 157         volatile psc512x_t *psc = (psc512x_t *) &im->psc[CONFIG_PSC_CONSOLE];
 158
 159         return !(psc->rfstat & PSC_FIFO_EMPTY);
 160 }
 161
 162 void serial_setbrg (void)
 163 {
 164         volatile immap_t *im = (immap_t *) CONFIG_SYS_IMMR;
 165         volatile psc512x_t *psc = (psc512x_t *) &im->psc[CONFIG_PSC_CONSOLE];
 166         unsigned long baseclk, div;
 167
 168         baseclk = (gd->csb_clk + 8) / 16;
 169         div = (baseclk + (gd->baudrate / 2)) / gd->baudrate;
 170
 171         psc->ctur = (div >> 8) & 0xFF;
 172         psc->ctlr =  div & 0xff; /* set baudrate */
 173 }
 174
 175 void serial_setrts(int s)
 176 {
 177         volatile immap_t *im = (immap_t *) CONFIG_SYS_IMMR;
 178         volatile psc512x_t *psc = (psc512x_t *) &im->psc[CONFIG_PSC_CONSOLE];
 179
 180         if (s) {
 181                 /* Assert RTS (become LOW) */
 182                 psc->op1 = 0x1;
 183         }
 184         else {
 185                 /* Negate RTS (become HIGH) */
 186                 psc->op0 = 0x1;
 187         }
 188 }
 189
 190 int serial_getcts(void)
 191 {
 192         volatile immap_t *im = (immap_t *) CONFIG_SYS_IMMR;
 193         volatile psc512x_t *psc = (psc512x_t *) &im->psc[CONFIG_PSC_CONSOLE];
 194
 195         return (psc->ip & 0x1) ? 0 : 1;
 196 }
 197 #endif /* CONFIG_PSC_CONSOLE */