uboot/arch/powerpc/cpu/mpc85xx/serial_scc.c
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   1/*
   2 * (C) Copyright 2003 Motorola Inc.
   3 * Xianghua Xiao (X.Xiao@motorola.com)
   4 * Modified based on 8260 for 8560.
   5 *
   6 * (C) Copyright 2000
   7 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   8 *
   9 * See file CREDITS for list of people who contributed to this
  10 * project.
  11 *
  12 * This program is free software; you can redistribute it and/or
  13 * modify it under the terms of the GNU General Public License as
  14 * published by the Free Software Foundation; either version 2 of
  15 * the License, or (at your option) any later version.
  16 *
  17 * This program is distributed in the hope that it will be useful,
  18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 * GNU General Public License for more details.
  21 *
  22 * You should have received a copy of the GNU General Public License
  23 * along with this program; if not, write to the Free Software
  24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  25 * MA 02111-1307 USA
  26 *
  27 * Hacked for MPC8260 by Murray.Jensen@cmst.csiro.au, 19-Oct-00.
  28 */
  29
  30/*
  31 * Minimal serial functions needed to use one of the SCC ports
  32 * as serial console interface.
  33 */
  34
  35#include <common.h>
  36#include <asm/cpm_85xx.h>
  37
  38DECLARE_GLOBAL_DATA_PTR;
  39
  40#if defined(CONFIG_CONS_ON_SCC)
  41
  42#if CONFIG_CONS_INDEX == 1      /* Console on SCC1 */
  43
  44#define SCC_INDEX               0
  45#define PROFF_SCC               PROFF_SCC1
  46#define CMXSCR_MASK             (CMXSCR_GR1|CMXSCR_SC1|\
  47                                        CMXSCR_RS1CS_MSK|CMXSCR_TS1CS_MSK)
  48#define CMXSCR_VALUE            (CMXSCR_RS1CS_BRG1|CMXSCR_TS1CS_BRG1)
  49#define CPM_CR_SCC_PAGE         CPM_CR_SCC1_PAGE
  50#define CPM_CR_SCC_SBLOCK       CPM_CR_SCC1_SBLOCK
  51
  52#elif CONFIG_CONS_INDEX == 2    /* Console on SCC2 */
  53
  54#define SCC_INDEX               1
  55#define PROFF_SCC               PROFF_SCC2
  56#define CMXSCR_MASK             (CMXSCR_GR2|CMXSCR_SC2|\
  57                                        CMXSCR_RS2CS_MSK|CMXSCR_TS2CS_MSK)
  58#define CMXSCR_VALUE            (CMXSCR_RS2CS_BRG2|CMXSCR_TS2CS_BRG2)
  59#define CPM_CR_SCC_PAGE         CPM_CR_SCC2_PAGE
  60#define CPM_CR_SCC_SBLOCK       CPM_CR_SCC2_SBLOCK
  61
  62#elif CONFIG_CONS_INDEX == 3    /* Console on SCC3 */
  63
  64#define SCC_INDEX               2
  65#define PROFF_SCC               PROFF_SCC3
  66#define CMXSCR_MASK             (CMXSCR_GR3|CMXSCR_SC3|\
  67                                        CMXSCR_RS3CS_MSK|CMXSCR_TS3CS_MSK)
  68#define CMXSCR_VALUE            (CMXSCR_RS3CS_BRG3|CMXSCR_TS3CS_BRG3)
  69#define CPM_CR_SCC_PAGE         CPM_CR_SCC3_PAGE
  70#define CPM_CR_SCC_SBLOCK       CPM_CR_SCC3_SBLOCK
  71
  72#elif CONFIG_CONS_INDEX == 4    /* Console on SCC4 */
  73
  74#define SCC_INDEX               3
  75#define PROFF_SCC               PROFF_SCC4
  76#define CMXSCR_MASK             (CMXSCR_GR4|CMXSCR_SC4|\
  77                                        CMXSCR_RS4CS_MSK|CMXSCR_TS4CS_MSK)
  78#define CMXSCR_VALUE            (CMXSCR_RS4CS_BRG4|CMXSCR_TS4CS_BRG4)
  79#define CPM_CR_SCC_PAGE         CPM_CR_SCC4_PAGE
  80#define CPM_CR_SCC_SBLOCK       CPM_CR_SCC4_SBLOCK
  81
  82#else
  83
  84#error "console not correctly defined"
  85
  86#endif
  87
  88int serial_init (void)
  89{
  90        volatile ccsr_cpm_t *cpm = (ccsr_cpm_t *)CONFIG_SYS_MPC85xx_CPM_ADDR;
  91        volatile ccsr_cpm_scc_t *sp;
  92        volatile scc_uart_t *up;
  93        volatile cbd_t *tbdf, *rbdf;
  94        volatile ccsr_cpm_cp_t *cp = &(cpm->im_cpm_cp);
  95        uint    dpaddr;
  96
  97        /* initialize pointers to SCC */
  98
  99        sp = (ccsr_cpm_scc_t *) &(cpm->im_cpm_scc[SCC_INDEX]);
 100        up = (scc_uart_t *)&(cpm->im_dprambase[PROFF_SCC]);
 101
 102        /* Disable transmitter/receiver.
 103        */
 104        sp->gsmrl &= ~(SCC_GSMRL_ENR | SCC_GSMRL_ENT);
 105
 106        /* put the SCC channel into NMSI (non multiplexd serial interface)
 107         * mode and wire the selected SCC Tx and Rx clocks to BRGx (15-15).
 108         */
 109        cpm->im_cpm_mux.cmxscr = \
 110                (cpm->im_cpm_mux.cmxscr&~CMXSCR_MASK)|CMXSCR_VALUE;
 111
 112        /* Set up the baud rate generator.
 113        */
 114        serial_setbrg ();
 115
 116        /* Allocate space for two buffer descriptors in the DP ram.
 117         * damm: allocating space after the two buffers for rx/tx data
 118         */
 119
 120        dpaddr = m8560_cpm_dpalloc((2 * sizeof (cbd_t)) + 2, 16);
 121
 122        /* Set the physical address of the host memory buffers in
 123         * the buffer descriptors.
 124         */
 125        rbdf = (cbd_t *)&(cpm->im_dprambase[dpaddr]);
 126        rbdf->cbd_bufaddr = (uint) (rbdf+2);
 127        rbdf->cbd_sc = BD_SC_EMPTY | BD_SC_WRAP;
 128        tbdf = rbdf + 1;
 129        tbdf->cbd_bufaddr = ((uint) (rbdf+2)) + 1;
 130        tbdf->cbd_sc = BD_SC_WRAP;
 131
 132        /* Set up the uart parameters in the parameter ram.
 133        */
 134        up->scc_genscc.scc_rbase = dpaddr;
 135        up->scc_genscc.scc_tbase = dpaddr+sizeof(cbd_t);
 136        up->scc_genscc.scc_rfcr = CPMFCR_EB;
 137        up->scc_genscc.scc_tfcr = CPMFCR_EB;
 138        up->scc_genscc.scc_mrblr = 1;
 139        up->scc_maxidl = 0;
 140        up->scc_brkcr = 1;
 141        up->scc_parec = 0;
 142        up->scc_frmec = 0;
 143        up->scc_nosec = 0;
 144        up->scc_brkec = 0;
 145        up->scc_uaddr1 = 0;
 146        up->scc_uaddr2 = 0;
 147        up->scc_toseq = 0;
 148        up->scc_char1 = up->scc_char2 = up->scc_char3 = up->scc_char4 = 0x8000;
 149        up->scc_char5 = up->scc_char6 = up->scc_char7 = up->scc_char8 = 0x8000;
 150        up->scc_rccm = 0xc0ff;
 151
 152        /* Mask all interrupts and remove anything pending.
 153        */
 154        sp->sccm = 0;
 155        sp->scce = 0xffff;
 156
 157        /* Set 8 bit FIFO, 16 bit oversampling and UART mode.
 158        */
 159        sp->gsmrh = SCC_GSMRH_RFW;      /* 8 bit FIFO */
 160        sp->gsmrl = \
 161                SCC_GSMRL_TDCR_16 | SCC_GSMRL_RDCR_16 | SCC_GSMRL_MODE_UART;
 162
 163        /* Set CTS no flow control, 1 stop bit, 8 bit character length,
 164         * normal async UART mode, no parity
 165         */
 166        sp->psmr = SCU_PSMR_CL;
 167
 168        /* execute the "Init Rx and Tx params" CP command.
 169        */
 170
 171        while (cp->cpcr & CPM_CR_FLG)  /* wait if cp is busy */
 172          ;
 173
 174        cp->cpcr = mk_cr_cmd(CPM_CR_SCC_PAGE, CPM_CR_SCC_SBLOCK,
 175                                        0, CPM_CR_INIT_TRX) | CPM_CR_FLG;
 176
 177        while (cp->cpcr & CPM_CR_FLG)  /* wait if cp is busy */
 178          ;
 179
 180        /* Enable transmitter/receiver.
 181        */
 182        sp->gsmrl |= SCC_GSMRL_ENR | SCC_GSMRL_ENT;
 183
 184        return (0);
 185}
 186
 187void
 188serial_setbrg (void)
 189{
 190#if defined(CONFIG_CONS_USE_EXTC)
 191        m8560_cpm_extcbrg(SCC_INDEX, gd->baudrate,
 192                CONFIG_CONS_EXTC_RATE, CONFIG_CONS_EXTC_PINSEL);
 193#else
 194        m8560_cpm_setbrg(SCC_INDEX, gd->baudrate);
 195#endif
 196}
 197
 198void
 199serial_putc(const char c)
 200{
 201        volatile scc_uart_t     *up;
 202        volatile cbd_t          *tbdf;
 203        volatile ccsr_cpm_t     *cpm = (ccsr_cpm_t *)CONFIG_SYS_MPC85xx_CPM_ADDR;
 204
 205        if (c == '\n')
 206                serial_putc ('\r');
 207
 208        up = (scc_uart_t *)&(cpm->im_dprambase[PROFF_SCC]);
 209        tbdf = (cbd_t *)&(cpm->im_dprambase[up->scc_genscc.scc_tbase]);
 210
 211        /* Wait for last character to go.
 212         */
 213        while (tbdf->cbd_sc & BD_SC_READY)
 214                ;
 215
 216        /* Load the character into the transmit buffer.
 217         */
 218        *(volatile char *)tbdf->cbd_bufaddr = c;
 219        tbdf->cbd_datlen = 1;
 220        tbdf->cbd_sc |= BD_SC_READY;
 221}
 222
 223void
 224serial_puts (const char *s)
 225{
 226        while (*s) {
 227                serial_putc (*s++);
 228        }
 229}
 230
 231int
 232serial_getc(void)
 233{
 234        volatile cbd_t          *rbdf;
 235        volatile scc_uart_t     *up;
 236        volatile ccsr_cpm_t     *cpm = (ccsr_cpm_t *)CONFIG_SYS_MPC85xx_CPM_ADDR;
 237        unsigned char           c;
 238
 239        up = (scc_uart_t *)&(cpm->im_dprambase[PROFF_SCC]);
 240        rbdf = (cbd_t *)&(cpm->im_dprambase[up->scc_genscc.scc_rbase]);
 241
 242        /* Wait for character to show up.
 243         */
 244        while (rbdf->cbd_sc & BD_SC_EMPTY)
 245                ;
 246
 247        /* Grab the char and clear the buffer again.
 248         */
 249        c = *(volatile unsigned char *)rbdf->cbd_bufaddr;
 250        rbdf->cbd_sc |= BD_SC_EMPTY;
 251
 252        return (c);
 253}
 254
 255int
 256serial_tstc()
 257{
 258        volatile cbd_t          *rbdf;
 259        volatile scc_uart_t     *up;
 260        volatile ccsr_cpm_t     *cpm = (ccsr_cpm_t *)CONFIG_SYS_MPC85xx_CPM_ADDR;
 261
 262        up = (scc_uart_t *)&(cpm->im_dprambase[PROFF_SCC]);
 263        rbdf = (cbd_t *)&(cpm->im_dprambase[up->scc_genscc.scc_rbase]);
 264
 265        return ((rbdf->cbd_sc & BD_SC_EMPTY) == 0);
 266}
 267
 268#endif  /* CONFIG_CONS_ON_SCC */
 269