common/cmd_spi.c

   1 /*
   2  * (C) Copyright 2002
   3  * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com
   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
  24 /*
  25  * SPI Read/Write Utilities
  26  */
  27
  28 #include <common.h>
  29 #include <command.h>
  30 #include <spi.h>
  31
  32 #if (CONFIG_COMMANDS & CFG_CMD_SPI)
  33
  34 /*-----------------------------------------------------------------------
  35  * Definitions
  36  */
  37
  38 #ifndef MAX_SPI_BYTES
  39 #   define MAX_SPI_BYTES 32     /* Maximum number of bytes we can handle */
  40 #endif
  41
  42 /*
  43  * External table of chip select functions (see the appropriate board
  44  * support for the actual definition of the table).
  45  */
  46 extern spi_chipsel_type spi_chipsel[];
  47 extern int spi_chipsel_cnt;
  48
  49 /*
  50  * Values from last command.
  51  */
  52 static int   device;
  53 static int   bitlen;
  54 static uchar dout[MAX_SPI_BYTES];
  55 static uchar din[MAX_SPI_BYTES];
  56
  57 /*
  58  * SPI read/write
  59  *
  60  * Syntax:
  61  *   spi {dev} {num_bits} {dout}
  62  *     {dev} is the device number for controlling chip select (see TBD)
  63  *     {num_bits} is the number of bits to send & receive (base 10)
  64  *     {dout} is a hexadecimal string of data to send
  65  * The command prints out the hexadecimal string received via SPI.
  66  */
  67
  68 int do_spi (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
  69 {
  70         char  *cp = 0;
  71         uchar tmp;
  72         int   j;
  73         int   rcode = 0;
  74
  75         /*
  76          * We use the last specified parameters, unless new ones are
  77          * entered.
  78          */
  79
  80         if ((flag & CMD_FLAG_REPEAT) == 0)
  81         {
  82                 if (argc >= 2)
  83                         device = simple_strtoul(argv[1], NULL, 10);
  84                 if (argc >= 3)
  85                         bitlen = simple_strtoul(argv[2], NULL, 10);
  86                 if (argc >= 4) {
  87                         cp = argv[3];
  88                         for(j = 0; *cp; j++, cp++) {
  89                                 tmp = *cp - '0';
  90                                 if(tmp > 9)
  91                                         tmp -= ('A' - '0') - 10;
  92                                 if(tmp > 15)
  93                                         tmp -= ('a' - 'A');
  94                                 if(tmp > 15) {
  95                                         printf("Hex conversion error on %c, giving up.\n", *cp);
  96                                         return 1;
  97                                 }
  98                                 if((j % 2) == 0)
  99                                         dout[j / 2] = (tmp << 4);
 100                                 else
 101                                         dout[j / 2] |= tmp;
 102                         }
 103                 }
 104         }
 105
 106         if ((device < 0) || (device >=  spi_chipsel_cnt)) {
 107                 printf("Invalid device %d, giving up.\n", device);
 108                 return 1;
 109         }
 110         if ((bitlen < 0) || (bitlen >  (MAX_SPI_BYTES * 8))) {
 111                 printf("Invalid bitlen %d, giving up.\n", bitlen);
 112                 return 1;
 113         }
 114
 115         debug ("spi_chipsel[%d] = %08X\n",
 116                 device, (uint)spi_chipsel[device]);
 117
 118         if(spi_xfer(spi_chipsel[device], bitlen, dout, din) != 0) {
 119                 printf("Error with the SPI transaction.\n");
 120                 rcode = 1;
 121         } else {
 122                 cp = din;
 123                 for(j = 0; j < ((bitlen + 7) / 8); j++) {
 124                         printf("%02X", *cp++);
 125                 }
 126                 printf("\n");
 127         }
 128
 129         return rcode;
 130 }
 131
 132 /***************************************************/
 133
 134 U_BOOT_CMD(
 135         sspi,   5,      1,      do_spi,
 136         "sspi     - SPI utility commands\n",
 137         "<device> <bit_len> <dout> - Send <bit_len> bits from <dout> out the SPI\n"
 138         "<device>  - Identifies the chip select of the device\n"
 139         "<bit_len> - Number of bits to send (base 10)\n"
 140         "<dout>    - Hexadecimal string that gets sent\n"
 141 );
 142
 143 #endif  /* CFG_CMD_SPI */