i386/linux-2.3.21/arch/ppc/mbxboot/mbxtty.c

   1
   2
   3 /* Minimal serial functions needed to send messages out the serial
   4  * port on the MBX console.
   5  *
   6  * The MBX uxes SMC1 for the serial port.  We reset the port and use
   7  * only the first BD that EPPC-Bug set up as a character FIFO.
   8  *
   9  * Later versions (at least 1.4, maybe earlier) of the MBX EPPC-Bug
  10  * use COM1 instead of SMC1 as the console port.  This kinda sucks
  11  * for the rest of the kernel, so here we force the use of SMC1 again.
  12  * I f**ked around for a day trying to figure out how to make EPPC-Bug
  13  * use SMC1, but gave up and decided to fix it here.
  14  */
  15 #include <linux/config.h>
  16 #include <linux/types.h>
  17 #ifdef CONFIG_MBX
  18 #include <asm/mbx.h>
  19 #endif
  20 #ifdef CONFIG_FADS
  21 #include <asm/fads.h>
  22 #endif
  23 #include "../8xx_io/commproc.h"
  24
  25 #ifdef CONFIG_MBX
  26 #define MBX_CSR1        ((volatile u_char *)0xfa100000)
  27 #define CSR1_COMEN      (u_char)0x02
  28 #endif
  29
  30 static cpm8xx_t *cpmp = (cpm8xx_t *)&(((immap_t *)IMAP_ADDR)->im_cpm);
  31
  32 void
  33 serial_init(bd_t *bd)
  34 {
  35         volatile smc_t          *sp;
  36         volatile smc_uart_t     *up;
  37         volatile cbd_t  *tbdf, *rbdf;
  38         volatile cpm8xx_t       *cp;
  39         uint    dpaddr, memaddr;
  40
  41         cp = cpmp;
  42         sp = (smc_t*)&(cp->cp_smc[0]);
  43         up = (smc_uart_t *)&cp->cp_dparam[PROFF_SMC1];
  44
  45         /* Disable transmitter/receiver.
  46         */
  47         sp->smc_smcmr &= ~(SMCMR_REN | SMCMR_TEN);
  48
  49 #ifdef CONFIG_MBX
  50         if (*MBX_CSR1 & CSR1_COMEN) {
  51                 /* COM1 is enabled.  Initialize SMC1 and use it for
  52                  * the console port.
  53                  */
  54
  55                 /* Enable SDMA.
  56                 */
  57                 ((immap_t *)IMAP_ADDR)->im_siu_conf.sc_sdcr = 1;
  58
  59                 /* Use Port B for SMCs instead of other functions.
  60                 */
  61                 cp->cp_pbpar |= 0x00000cc0;
  62                 cp->cp_pbdir &= ~0x00000cc0;
  63                 cp->cp_pbodr &= ~0x00000cc0;
  64
  65                 /* Allocate space for two buffer descriptors in the DP ram.
  66                  * For now, this address seems OK, but it may have to
  67                  * change with newer versions of the firmware.
  68                  */
  69                 dpaddr = 0x0800;
  70
  71                 /* Grab a few bytes from the top of memory.  EPPC-Bug isn't
  72                  * running any more, so we can do this.
  73                  */
  74                 memaddr = (bd->bi_memsize - 32) & ~15;
  75
  76                 /* Set the physical address of the host memory buffers in
  77                  * the buffer descriptors.
  78                  */
  79                 rbdf = (cbd_t *)&cp->cp_dpmem[dpaddr];
  80                 rbdf->cbd_bufaddr = memaddr;
  81                 rbdf->cbd_sc = 0;
  82                 tbdf = rbdf + 1;
  83                 tbdf->cbd_bufaddr = memaddr+4;
  84                 tbdf->cbd_sc = 0;
  85
  86                 /* Set up the uart parameters in the parameter ram.
  87                 */
  88                 up->smc_rbase = dpaddr;
  89                 up->smc_tbase = dpaddr+sizeof(cbd_t);
  90                 up->smc_rfcr = SMC_EB;
  91                 up->smc_tfcr = SMC_EB;
  92
  93                 /* Set UART mode, 8 bit, no parity, one stop.
  94                  * Enable receive and transmit.
  95                  */
  96                 sp->smc_smcmr = smcr_mk_clen(9) |  SMCMR_SM_UART;
  97
  98                 /* Mask all interrupts and remove anything pending.
  99                 */
 100                 sp->smc_smcm = 0;
 101                 sp->smc_smce = 0xff;
 102
 103                 /* Set up the baud rate generator.
 104                  * See 8xx_io/commproc.c for details.
 105                  */
 106                 cp->cp_simode = 0x10000000;
 107                 cp->cp_brgc1 =
 108                         ((((bd->bi_intfreq * 1000000)/16) / 9600) << 1) | CPM_BRG_EN;
 109
 110                 /* Enable SMC1 for console output.
 111                 */
 112                 *MBX_CSR1 &= ~CSR1_COMEN;
 113         }
 114         else {
 115 #endif
 116                 /* SMC1 is used as console port.
 117                 */
 118                 tbdf = (cbd_t *)&cp->cp_dpmem[up->smc_tbase];
 119                 rbdf = (cbd_t *)&cp->cp_dpmem[up->smc_rbase];
 120
 121                 /* Issue a stop transmit, and wait for it.
 122                 */
 123                 cp->cp_cpcr = mk_cr_cmd(CPM_CR_CH_SMC1,
 124                                         CPM_CR_STOP_TX) | CPM_CR_FLG;
 125                 while (cp->cp_cpcr & CPM_CR_FLG);
 126 #ifdef CONFIG_MBX
 127         }
 128 #endif
 129
 130         /* Make the first buffer the only buffer.
 131         */
 132         tbdf->cbd_sc |= BD_SC_WRAP;
 133         rbdf->cbd_sc |= BD_SC_EMPTY | BD_SC_WRAP;
 134
 135         /* Single character receive.
 136         */
 137         up->smc_mrblr = 1;
 138         up->smc_maxidl = 0;
 139
 140         /* Initialize Tx/Rx parameters.
 141         */
 142         cp->cp_cpcr = mk_cr_cmd(CPM_CR_CH_SMC1, CPM_CR_INIT_TRX) | CPM_CR_FLG;
 143         while (cp->cp_cpcr & CPM_CR_FLG);
 144
 145         /* Enable transmitter/receiver.
 146         */
 147         sp->smc_smcmr |= SMCMR_REN | SMCMR_TEN;
 148 }
 149
 150 void
 151 serial_putchar(const char c)
 152 {
 153         volatile cbd_t          *tbdf;
 154         volatile char           *buf;
 155         volatile smc_uart_t     *up;
 156
 157         up = (smc_uart_t *)&cpmp->cp_dparam[PROFF_SMC1];
 158         tbdf = (cbd_t *)&cpmp->cp_dpmem[up->smc_tbase];
 159
 160         /* Wait for last character to go.
 161         */
 162         buf = (char *)tbdf->cbd_bufaddr;
 163         while (tbdf->cbd_sc & BD_SC_READY);
 164
 165         *buf = c;
 166         tbdf->cbd_datlen = 1;
 167         tbdf->cbd_sc |= BD_SC_READY;
 168 }
 169
 170 char
 171 serial_getc()
 172 {
 173         volatile cbd_t          *rbdf;
 174         volatile char           *buf;
 175         volatile smc_uart_t     *up;
 176         char                    c;
 177
 178         up = (smc_uart_t *)&cpmp->cp_dparam[PROFF_SMC1];
 179         rbdf = (cbd_t *)&cpmp->cp_dpmem[up->smc_rbase];
 180
 181         /* Wait for character to show up.
 182         */
 183         buf = (char *)rbdf->cbd_bufaddr;
 184         while (rbdf->cbd_sc & BD_SC_EMPTY);
 185         c = *buf;
 186         rbdf->cbd_sc |= BD_SC_EMPTY;
 187
 188         return(c);
 189 }
 190
 191 int
 192 serial_tstc()
 193 {
 194         volatile cbd_t          *rbdf;
 195         volatile smc_uart_t     *up;
 196
 197         up = (smc_uart_t *)&cpmp->cp_dparam[PROFF_SMC1];
 198         rbdf = (cbd_t *)&cpmp->cp_dpmem[up->smc_rbase];
 199
 200         return(!(rbdf->cbd_sc & BD_SC_EMPTY));
 201 }