arch/powerpc/cpu/mpc5xx/serial.c

   1 /*
   2  * (C) Copyright 2003
   3  * Martin Winistoerfer, martinwinistoerfer@gmx.ch.
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 /*
   9  * File:                serial.c
  10  *
  11  * Discription:         Serial interface driver for SCI1 and SCI2.
  12  *                      Since this code will be called from ROM use
  13  *                      only non-static local variables.
  14  *
  15  */
  16
  17 #include <common.h>
  18 #include <watchdog.h>
  19 #include <command.h>
  20 #include <mpc5xx.h>
  21 #include <serial.h>
  22 #include <linux/compiler.h>
  23
  24 DECLARE_GLOBAL_DATA_PTR;
  25
  26 /*
  27  * Local functions
  28  */
  29
  30 static int ready_to_send(void)
  31 {
  32         volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
  33         volatile short status;
  34
  35         do {
  36 #if defined(CONFIG_5xx_CONS_SCI1)
  37                 status = immr->im_qsmcm.qsmcm_sc1sr;
  38 #else
  39                 status = immr->im_qsmcm.qsmcm_sc2sr;
  40 #endif
  41
  42 #if defined(CONFIG_WATCHDOG)
  43                 reset_5xx_watchdog (immr);
  44 #endif
  45         } while ((status & SCI_TDRE) == 0);
  46         return 1;
  47
  48 }
  49
  50 /*
  51  * Minimal global serial functions needed to use one of the SCI modules.
  52  */
  53
  54 static int mpc5xx_serial_init(void)
  55 {
  56         volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
  57
  58         serial_setbrg();
  59
  60 #if defined(CONFIG_5xx_CONS_SCI1)
  61         /* 10-Bit, 1 start bit, 8 data bit, no parity, 1 stop bit */
  62         immr->im_qsmcm.qsmcm_scc1r1 = SCI_M_10;
  63         immr->im_qsmcm.qsmcm_scc1r1 = SCI_TE | SCI_RE;
  64 #else
  65         immr->im_qsmcm.qsmcm_scc2r1 = SCI_M_10;
  66         immr->im_qsmcm.qsmcm_scc2r1 = SCI_TE | SCI_RE;
  67 #endif
  68         return 0;
  69 }
  70
  71 static void mpc5xx_serial_putc(const char c)
  72 {
  73         volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
  74
  75         /* Test for completition */
  76         if(ready_to_send()) {
  77 #if defined(CONFIG_5xx_CONS_SCI1)
  78                 immr->im_qsmcm.qsmcm_sc1dr = (short)c;
  79 #else
  80                 immr->im_qsmcm.qsmcm_sc2dr = (short)c;
  81 #endif
  82                 if(c == '\n') {
  83                         if(ready_to_send());
  84 #if defined(CONFIG_5xx_CONS_SCI1)
  85                         immr->im_qsmcm.qsmcm_sc1dr = (short)'\r';
  86 #else
  87                         immr->im_qsmcm.qsmcm_sc2dr = (short)'\r';
  88 #endif
  89                 }
  90         }
  91 }
  92
  93 static int mpc5xx_serial_getc(void)
  94 {
  95         volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
  96         volatile short status;
  97         unsigned char tmp;
  98
  99         /* New data ? */
 100         do {
 101 #if defined(CONFIG_5xx_CONS_SCI1)
 102                 status = immr->im_qsmcm.qsmcm_sc1sr;
 103 #else
 104                 status = immr->im_qsmcm.qsmcm_sc2sr;
 105 #endif
 106
 107 #if defined(CONFIG_WATCHDOG)
 108                 reset_5xx_watchdog (immr);
 109 #endif
 110         } while ((status & SCI_RDRF) == 0);
 111
 112         /* Read data */
 113 #if defined(CONFIG_5xx_CONS_SCI1)
 114         tmp = (unsigned char)(immr->im_qsmcm.qsmcm_sc1dr & SCI_SCXDR_MK);
 115 #else
 116         tmp = (unsigned char)( immr->im_qsmcm.qsmcm_sc2dr & SCI_SCXDR_MK);
 117 #endif
 118         return  tmp;
 119 }
 120
 121 static int mpc5xx_serial_tstc(void)
 122 {
 123         volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
 124         short status;
 125
 126         /* New data character ? */
 127 #if defined(CONFIG_5xx_CONS_SCI1)
 128         status = immr->im_qsmcm.qsmcm_sc1sr;
 129 #else
 130         status = immr->im_qsmcm.qsmcm_sc2sr;
 131 #endif
 132         return (status & SCI_RDRF);
 133 }
 134
 135 static void mpc5xx_serial_setbrg(void)
 136 {
 137         volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
 138         short scxbr;
 139
 140         /* Set baudrate */
 141         scxbr = (gd->cpu_clk / (32 * gd->baudrate));
 142 #if defined(CONFIG_5xx_CONS_SCI1)
 143         immr->im_qsmcm.qsmcm_scc1r0 = (scxbr & SCI_SCXBR_MK);
 144 #else
 145         immr->im_qsmcm.qsmcm_scc2r0 = (scxbr & SCI_SCXBR_MK);
 146 #endif
 147 }
 148
 149 static struct serial_device mpc5xx_serial_drv = {
 150         .name   = "mpc5xx_serial",
 151         .start  = mpc5xx_serial_init,
 152         .stop   = NULL,
 153         .setbrg = mpc5xx_serial_setbrg,
 154         .putc   = mpc5xx_serial_putc,
 155         .puts   = default_serial_puts,
 156         .getc   = mpc5xx_serial_getc,
 157         .tstc   = mpc5xx_serial_tstc,
 158 };
 159
 160 void mpc5xx_serial_initialize(void)
 161 {
 162         serial_register(&mpc5xx_serial_drv);
 163 }
 164
 165 __weak struct serial_device *default_serial_console(void)
 166 {
 167         return &mpc5xx_serial_drv;
 168 }