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   1 /*
   2  * Copyright © 2009 Keith Packard <keithp@keithp.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; version 2 of the License.
   7  *
   8  * This program is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  16  */
  17
  18 #include "ao.h"
  19 #include "25lc1024.h"
  20
  21 /*
  22  * Using SPI on USART 0, with P1_2 as the chip select
  23  */
  24
  25 #define EE_CS           P1_2
  26 #define EE_CS_INDEX     2
  27
  28 __xdata uint8_t ao_ee_mutex;
  29
  30 #define ao_ee_delay() do { \
  31         _asm nop _endasm; \
  32         _asm nop _endasm; \
  33         _asm nop _endasm; \
  34 } while(0)
  35
  36 void ao_ee_cs_low(void)
  37 {
  38         ao_ee_delay();
  39         EE_CS = 0;
  40         ao_ee_delay();
  41 }
  42
  43 void ao_ee_cs_high(void)
  44 {
  45         ao_ee_delay();
  46         EE_CS = 1;
  47         ao_ee_delay();
  48 }
  49
  50
  51 #define EE_BLOCK        256
  52
  53 struct ao_ee_instruction {
  54         uint8_t instruction;
  55         uint8_t address[3];
  56 } __xdata ao_ee_instruction;
  57
  58 static void
  59 ao_ee_write_enable(void)
  60 {
  61         ao_ee_cs_low();
  62         ao_ee_instruction.instruction = EE_WREN;
  63         ao_spi_send(&ao_ee_instruction, 1);
  64         ao_ee_cs_high();
  65 }
  66
  67 static uint8_t
  68 ao_ee_rdsr(void)
  69 {
  70         ao_ee_cs_low();
  71         ao_ee_instruction.instruction = EE_RDSR;
  72         ao_spi_send(&ao_ee_instruction, 1);
  73         ao_spi_recv(&ao_ee_instruction, 1);
  74         ao_ee_cs_high();
  75         return ao_ee_instruction.instruction;
  76 }
  77
  78 static void
  79 ao_ee_wrsr(uint8_t status)
  80 {
  81         ao_ee_cs_low();
  82         ao_ee_instruction.instruction = EE_WRSR;
  83         ao_ee_instruction.address[0] = status;
  84         ao_spi_send(&ao_ee_instruction, 2);
  85         ao_ee_cs_high();
  86 }
  87
  88 #define EE_BLOCK_NONE   0xffff
  89
  90 static __xdata uint8_t ao_ee_data[EE_BLOCK];
  91 static __pdata uint16_t ao_ee_block = EE_BLOCK_NONE;
  92 static __pdata uint8_t  ao_ee_block_dirty;
  93
  94 /* Write the current block to the EEPROM */
  95 static void
  96 ao_ee_write_block(void)
  97 {
  98         uint8_t status;
  99
 100         status = ao_ee_rdsr();
 101         if (status & (EE_STATUS_BP0|EE_STATUS_BP1|EE_STATUS_WPEN)) {
 102                 status &= ~(EE_STATUS_BP0|EE_STATUS_BP1|EE_STATUS_WPEN);
 103                 ao_ee_wrsr(status);
 104         }
 105         ao_ee_write_enable();
 106         ao_ee_cs_low();
 107         ao_ee_instruction.instruction = EE_WRITE;
 108         ao_ee_instruction.address[0] = ao_ee_block >> 8;
 109         ao_ee_instruction.address[1] = ao_ee_block;
 110         ao_ee_instruction.address[2] = 0;
 111         ao_spi_send(&ao_ee_instruction, 4);
 112         ao_spi_send(ao_ee_data, EE_BLOCK);
 113         ao_ee_cs_high();
 114         for (;;) {
 115                 uint8_t status = ao_ee_rdsr();
 116                 if ((status & EE_STATUS_WIP) == 0)
 117                         break;
 118         }
 119 }
 120
 121 /* Read the current block from the EEPROM */
 122 static void
 123 ao_ee_read_block(void)
 124 {
 125         ao_ee_cs_low();
 126         ao_ee_instruction.instruction = EE_READ;
 127         ao_ee_instruction.address[0] = ao_ee_block >> 8;
 128         ao_ee_instruction.address[1] = ao_ee_block;
 129         ao_ee_instruction.address[2] = 0;
 130         ao_spi_send(&ao_ee_instruction, 4);
 131         ao_spi_recv(ao_ee_data, EE_BLOCK);
 132         ao_ee_cs_high();
 133 }
 134
 135 static void
 136 ao_ee_flush_internal(void)
 137 {
 138         if (ao_ee_block_dirty) {
 139                 ao_ee_write_block();
 140                 ao_ee_block_dirty = 0;
 141         }
 142 }
 143
 144 static void
 145 ao_ee_fill(uint16_t block)
 146 {
 147         if (block != ao_ee_block) {
 148                 ao_ee_flush_internal();
 149                 ao_ee_block = block;
 150                 ao_ee_read_block();
 151         }
 152 }
 153
 154 uint8_t
 155 ao_ee_write(uint32_t pos, uint8_t *buf, uint16_t len) __reentrant
 156 {
 157         uint16_t block;
 158         uint16_t this_len;
 159         uint8_t this_off;
 160
 161         if (pos >= AO_EE_DATA_SIZE || pos + len > AO_EE_DATA_SIZE)
 162                 return 0;
 163         while (len) {
 164
 165                 /* Compute portion of transfer within
 166                  * a single block
 167                  */
 168                 this_off = pos;
 169                 this_len = 256 - (uint16_t) this_off;
 170                 block = (uint16_t) (pos >> 8);
 171                 if (this_len > len)
 172                         this_len = len;
 173                 if (this_len & 0xff00)
 174                         ao_panic(AO_PANIC_EE);
 175
 176                 /* Transfer the data */
 177                 ao_mutex_get(&ao_ee_mutex); {
 178                         if (this_len != 256)
 179                                 ao_ee_fill(block);
 180                         else {
 181                                 ao_ee_flush_internal();
 182                                 ao_ee_block = block;
 183                         }
 184                         memcpy(ao_ee_data + this_off, buf, this_len);
 185                         ao_ee_block_dirty = 1;
 186                 } ao_mutex_put(&ao_ee_mutex);
 187
 188                 /* See how much is left */
 189                 buf += this_len;
 190                 len -= this_len;
 191                 pos += this_len;
 192         }
 193         return 1;
 194 }
 195
 196 uint8_t
 197 ao_ee_read(uint32_t pos, uint8_t *buf, uint16_t len) __reentrant
 198 {
 199         uint16_t block;
 200         uint16_t this_len;
 201         uint8_t this_off;
 202
 203         if (pos >= AO_EE_DATA_SIZE || pos + len > AO_EE_DATA_SIZE)
 204                 return 0;
 205         while (len) {
 206
 207                 /* Compute portion of transfer within
 208                  * a single block
 209                  */
 210                 this_off = pos;
 211                 this_len = 256 - (uint16_t) this_off;
 212                 block = (uint16_t) (pos >> 8);
 213                 if (this_len > len)
 214                         this_len = len;
 215                 if (this_len & 0xff00)
 216                         ao_panic(AO_PANIC_EE);
 217
 218                 /* Transfer the data */
 219                 ao_mutex_get(&ao_ee_mutex); {
 220                         ao_ee_fill(block);
 221                         memcpy(buf, ao_ee_data + this_off, this_len);
 222                 } ao_mutex_put(&ao_ee_mutex);
 223
 224                 /* See how much is left */
 225                 buf += this_len;
 226                 len -= this_len;
 227                 pos += this_len;
 228         }
 229         return 1;
 230 }
 231
 232 void
 233 ao_ee_flush(void) __reentrant
 234 {
 235         ao_mutex_get(&ao_ee_mutex); {
 236                 ao_ee_flush_internal();
 237         } ao_mutex_put(&ao_ee_mutex);
 238 }
 239
 240 /*
 241  * Read/write the config block, which is in
 242  * the last block of the ao_eeprom
 243  */
 244 uint8_t
 245 ao_ee_write_config(uint8_t *buf, uint16_t len) __reentrant
 246 {
 247         if (len > AO_EE_BLOCK_SIZE)
 248                 return 0;
 249         ao_mutex_get(&ao_ee_mutex); {
 250                 ao_ee_fill(AO_EE_CONFIG_BLOCK);
 251                 memcpy(ao_ee_data, buf, len);
 252                 ao_ee_block_dirty = 1;
 253                 ao_ee_flush_internal();
 254         } ao_mutex_put(&ao_ee_mutex);
 255         return 1;
 256 }
 257
 258 uint8_t
 259 ao_ee_read_config(uint8_t *buf, uint16_t len) __reentrant
 260 {
 261         if (len > AO_EE_BLOCK_SIZE)
 262                 return 0;
 263         ao_mutex_get(&ao_ee_mutex); {
 264                 ao_ee_fill(AO_EE_CONFIG_BLOCK);
 265                 memcpy(buf, ao_ee_data, len);
 266         } ao_mutex_put(&ao_ee_mutex);
 267         return 1;
 268 }
 269
 270 static void
 271 ee_dump(void) __reentrant
 272 {
 273         uint8_t b;
 274         uint16_t block;
 275         uint8_t i;
 276
 277         ao_cmd_hex();
 278         block = ao_cmd_lex_i;
 279         if (ao_cmd_status != ao_cmd_success)
 280                 return;
 281         i = 0;
 282         do {
 283                 if ((i & 7) == 0) {
 284                         if (i)
 285                                 putchar('\n');
 286                         ao_cmd_put16((uint16_t) i);
 287                 }
 288                 putchar(' ');
 289                 ao_ee_read(((uint32_t) block << 8) | i, &b, 1);
 290                 ao_cmd_put8(b);
 291                 ++i;
 292         } while (i != 0);
 293         putchar('\n');
 294 }
 295
 296 static void
 297 ee_store(void) __reentrant
 298 {
 299         uint16_t block;
 300         uint8_t i;
 301         uint16_t len;
 302         uint8_t b;
 303         uint32_t addr;
 304
 305         ao_cmd_hex();
 306         block = ao_cmd_lex_i;
 307         ao_cmd_hex();
 308         i = ao_cmd_lex_i;
 309         addr = ((uint32_t) block << 8) | i;
 310         ao_cmd_hex();
 311         len = ao_cmd_lex_i;
 312         if (ao_cmd_status != ao_cmd_success)
 313                 return;
 314         while (len--) {
 315                 ao_cmd_hex();
 316                 if (ao_cmd_status != ao_cmd_success)
 317                         return;
 318                 b = ao_cmd_lex_i;
 319                 ao_ee_write(addr, &b, 1);
 320                 addr++;
 321         }
 322         ao_ee_flush();
 323 }
 324
 325 __code struct ao_cmds ao_ee_cmds[] = {
 326         { 'e', ee_dump,         "e <block>                          Dump a block of EEPROM data" },
 327         { 'w', ee_store,        "w <block> <start> <len> <data> ... Write data to EEPROM" },
 328         { 0,   ee_store, NULL },
 329 };
 330
 331 /*
 332  * To initialize the chip, set up the CS line and
 333  * the SPI interface
 334  */
 335 void
 336 ao_ee_init(void)
 337 {
 338         /* set up CS */
 339         EE_CS = 1;
 340         P1DIR |= (1 << EE_CS_INDEX);
 341         P1SEL &= ~(1 << EE_CS_INDEX);
 342
 343         ao_cmd_register(&ao_ee_cmds[0]);
 344 }