drivers/block/systemace.c

   1 /*
   2  * Copyright (c) 2004 Picture Elements, Inc.
   3  *    Stephen Williams (XXXXXXXXXXXXXXXX)
   4  *
   5  *    This source code is free software; you can redistribute it
   6  *    and/or modify it in source code form under the terms of the GNU
   7  *    General Public License as published by the Free Software
   8  *    Foundation; either version 2 of the License, or (at your option)
   9  *    any later version.
  10  *
  11  *    This program is distributed in the hope that it will be useful,
  12  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *    GNU General Public License for more details.
  15  *
  16  *    You should have received a copy of the GNU General Public License
  17  *    along with this program; if not, write to the Free Software
  18  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  19  */
  20
  21 /*
  22  * The Xilinx SystemACE chip support is activated by defining
  23  * CONFIG_SYSTEMACE to turn on support, and CONFIG_SYS_SYSTEMACE_BASE
  24  * to set the base address of the device. This code currently
  25  * assumes that the chip is connected via a byte-wide bus.
  26  *
  27  * The CONFIG_SYSTEMACE also adds to fat support the device class
  28  * "ace" that allows the user to execute "fatls ace 0" and the
  29  * like. This works by making the systemace_get_dev function
  30  * available to cmd_fat.c:get_dev and filling in a block device
  31  * description that has all the bits needed for FAT support to
  32  * read sectors.
  33  *
  34  * According to Xilinx technical support, before accessing the
  35  * SystemACE CF you need to set the following control bits:
  36  *      FORCECFGMODE : 1
  37  *      CFGMODE : 0
  38  *      CFGSTART : 0
  39  */
  40
  41 #include <common.h>
  42 #include <command.h>
  43 #include <systemace.h>
  44 #include <part.h>
  45 #include <asm/io.h>
  46
  47 /*
  48  * The ace_readw and writew functions read/write 16bit words, but the
  49  * offset value is the BYTE offset as most used in the Xilinx
  50  * datasheet for the SystemACE chip. The CONFIG_SYS_SYSTEMACE_BASE is defined
  51  * to be the base address for the chip, usually in the local
  52  * peripheral bus.
  53  */
  54
  55 static u32 base = CONFIG_SYS_SYSTEMACE_BASE;
  56 static u32 width = CONFIG_SYS_SYSTEMACE_WIDTH;
  57
  58 static void ace_writew(u16 val, unsigned off)
  59 {
  60         if (width == 8) {
  61 #if !defined(__BIG_ENDIAN)
  62                 writeb(val >> 8, base + off);
  63                 writeb(val, base + off + 1);
  64 #else
  65                 writeb(val, base + off);
  66                 writeb(val >> 8, base + off + 1);
  67 #endif
  68         }
  69         out16(base + off, val);
  70 }
  71
  72 static u16 ace_readw(unsigned off)
  73 {
  74         if (width == 8) {
  75 #if !defined(__BIG_ENDIAN)
  76                 return (readb(base + off) << 8) | readb(base + off + 1);
  77 #else
  78                 return readb(base + off) | (readb(base + off + 1) << 8);
  79 #endif
  80         }
  81
  82         return in16(base + off);
  83 }
  84
  85 static unsigned long systemace_read(int dev, unsigned long start,
  86                                     unsigned long blkcnt, void *buffer);
  87
  88 static block_dev_desc_t systemace_dev = { 0 };
  89
  90 static int get_cf_lock(void)
  91 {
  92         int retry = 10;
  93
  94         /* CONTROLREG = LOCKREG */
  95         unsigned val = ace_readw(0x18);
  96         val |= 0x0002;
  97         ace_writew((val & 0xffff), 0x18);
  98
  99         /* Wait for MPULOCK in STATUSREG[15:0] */
 100         while (!(ace_readw(0x04) & 0x0002)) {
 101
 102                 if (retry < 0)
 103                         return -1;
 104
 105                 udelay(100000);
 106                 retry -= 1;
 107         }
 108
 109         return 0;
 110 }
 111
 112 static void release_cf_lock(void)
 113 {
 114         unsigned val = ace_readw(0x18);
 115         val &= ~(0x0002);
 116         ace_writew((val & 0xffff), 0x18);
 117 }
 118
 119 #ifdef CONFIG_PARTITIONS
 120 block_dev_desc_t *systemace_get_dev(int dev)
 121 {
 122         /* The first time through this, the systemace_dev object is
 123            not yet initialized. In that case, fill it in. */
 124         if (systemace_dev.blksz == 0) {
 125                 systemace_dev.if_type = IF_TYPE_UNKNOWN;
 126                 systemace_dev.dev = 0;
 127                 systemace_dev.part_type = PART_TYPE_UNKNOWN;
 128                 systemace_dev.type = DEV_TYPE_HARDDISK;
 129                 systemace_dev.blksz = 512;
 130                 systemace_dev.removable = 1;
 131                 systemace_dev.block_read = systemace_read;
 132
 133                 /*
 134                  * Ensure the correct bus mode (8/16 bits) gets enabled
 135                  */
 136                 ace_writew(width == 8 ? 0 : 0x0001, 0);
 137
 138                 init_part(&systemace_dev);
 139
 140         }
 141
 142         return &systemace_dev;
 143 }
 144 #endif
 145
 146 /*
 147  * This function is called (by dereferencing the block_read pointer in
 148  * the dev_desc) to read blocks of data. The return value is the
 149  * number of blocks read. A zero return indicates an error.
 150  */
 151 static unsigned long systemace_read(int dev, unsigned long start,
 152                                     unsigned long blkcnt, void *buffer)
 153 {
 154         int retry;
 155         unsigned blk_countdown;
 156         unsigned char *dp = buffer;
 157         unsigned val;
 158
 159         if (get_cf_lock() < 0) {
 160                 unsigned status = ace_readw(0x04);
 161
 162                 /* If CFDETECT is false, card is missing. */
 163                 if (!(status & 0x0010)) {
 164                         printf("** CompactFlash card not present. **\n");
 165                         return 0;
 166                 }
 167
 168                 printf("**** ACE locked away from me (STATUSREG=%04x)\n",
 169                        status);
 170                 return 0;
 171         }
 172 #ifdef DEBUG_SYSTEMACE
 173         printf("... systemace read %lu sectors at %lu\n", blkcnt, start);
 174 #endif
 175
 176         retry = 2000;
 177         for (;;) {
 178                 val = ace_readw(0x04);
 179
 180                 /* If CFDETECT is false, card is missing. */
 181                 if (!(val & 0x0010)) {
 182                         printf("**** ACE CompactFlash not found.\n");
 183                         release_cf_lock();
 184                         return 0;
 185                 }
 186
 187                 /* If RDYFORCMD, then we are ready to go. */
 188                 if (val & 0x0100)
 189                         break;
 190
 191                 if (retry < 0) {
 192                         printf("**** SystemACE not ready.\n");
 193                         release_cf_lock();
 194                         return 0;
 195                 }
 196
 197                 udelay(1000);
 198                 retry -= 1;
 199         }
 200
 201         /* The SystemACE can only transfer 256 sectors at a time, so
 202            limit the current chunk of sectors. The blk_countdown
 203            variable is the number of sectors left to transfer. */
 204
 205         blk_countdown = blkcnt;
 206         while (blk_countdown > 0) {
 207                 unsigned trans = blk_countdown;
 208
 209                 if (trans > 256)
 210                         trans = 256;
 211
 212 #ifdef DEBUG_SYSTEMACE
 213                 printf("... transfer %lu sector in a chunk\n", trans);
 214 #endif
 215                 /* Write LBA block address */
 216                 ace_writew((start >> 0) & 0xffff, 0x10);
 217                 ace_writew((start >> 16) & 0x0fff, 0x12);
 218
 219                 /* NOTE: in the Write Sector count below, a count of 0
 220                    causes a transfer of 256, so &0xff gives the right
 221                    value for whatever transfer count we want. */
 222
 223                 /* Write sector count | ReadMemCardData. */
 224                 ace_writew((trans & 0xff) | 0x0300, 0x14);
 225
 226 /*
 227  * For FPGA configuration via SystemACE is reset unacceptable
 228  * CFGDONE bit in STATUSREG is not set to 1.
 229  */
 230 #ifndef SYSTEMACE_CONFIG_FPGA
 231                 /* Reset the configruation controller */
 232                 val = ace_readw(0x18);
 233                 val |= 0x0080;
 234                 ace_writew(val, 0x18);
 235 #endif
 236
 237                 retry = trans * 16;
 238                 while (retry > 0) {
 239                         int idx;
 240
 241                         /* Wait for buffer to become ready. */
 242                         while (!(ace_readw(0x04) & 0x0020)) {
 243                                 udelay(100);
 244                         }
 245
 246                         /* Read 16 words of 2bytes from the sector buffer. */
 247                         for (idx = 0; idx < 16; idx += 1) {
 248                                 unsigned short val = ace_readw(0x40);
 249                                 *dp++ = val & 0xff;
 250                                 *dp++ = (val >> 8) & 0xff;
 251                         }
 252
 253                         retry -= 1;
 254                 }
 255
 256                 /* Clear the configruation controller reset */
 257                 val = ace_readw(0x18);
 258                 val &= ~0x0080;
 259                 ace_writew(val, 0x18);
 260
 261                 /* Count the blocks we transfer this time. */
 262                 start += trans;
 263                 blk_countdown -= trans;
 264         }
 265
 266         release_cf_lock();
 267
 268         return blkcnt;
 269 }