diff options
Diffstat (limited to 'src/storage.cc')
| -rw-r--r-- | src/storage.cc | 104 |
1 files changed, 68 insertions, 36 deletions
diff --git a/src/storage.cc b/src/storage.cc index a517f53..21eed31 100644 --- a/src/storage.cc +++ b/src/storage.cc @@ -1,3 +1,4 @@ +#include <util/delay.h> #include <avr/io.h> #include <stdlib.h> @@ -8,12 +9,12 @@ Storage storage; /* * EEPROM data structure ("file system"): * - * Organized as 64B-pages, all animations/texts are page-aligned. Byte 0 .. + * Organized as 32B-pages, all animations/texts are page-aligned. Byte 0 .. * 255 : storage metadata. Byte 0 contains the number of animations, byte 1 the * page offset of the first animation, byte 2 of the second, and so on. * Byte 256+: texts/animations without additional storage metadata, aligned - * to 64B. So, a maximum of 256-(256/64) = 252 texts/animations can be stored, - * and a maximum of 255 * 64 = 16320 Bytes (almost 16 kB / 128 kbit) can be + * to 32B. So, a maximum of 256-(256/32) = 248 texts/animations can be stored, + * and a maximum of 255 * 32 = 8160 Bytes (almost 8 kB / 64 kbit) can be * addressed. To support larger EEPROMS, change the metadate area to Byte 2 .. * 511 and use 16bit page pointers. * @@ -21,16 +22,16 @@ Storage storage; * * Example: * Byte 0 = 3 -> we've got a total of three animations - * Byte 1 = 4 -> first text/animation starts at byte 64*4 = 256 - * Byte 2 = 8 -> second starts at byte 64*8 = 512 - * Byte 3 = 9 -> third starts at 64*9 * 576 + * Byte 1 = 0 -> first text/animation starts at byte 256 + 32*0 = 256 + * Byte 2 = 4 -> second starts at byte 256 + 32*4 = 384 + * Byte 3 = 5 -> third starts at 256 + 32*5 * 416 * Byte 4 = whatever * . * . * . * Byte 256ff = first text/animation. Has a header encoding its length in bytes. - * Byte 512ff = second - * Byte 576ff = third + * Byte 384ff = second + * Byte 416ff = third * . * . * . @@ -47,7 +48,7 @@ void Storage::enable() TWSR = 0; // the lower two bits control TWPS TWBR = ((F_CPU / 100000UL) - 16) / 2; - i2c_read(0, 1, &num_anims); + i2c_read(0, 0, 1, &num_anims); } @@ -117,7 +118,7 @@ uint8_t Storage::i2c_send(uint8_t len, uint8_t *data) return pos; } - return pos + 1; + return pos; } /* @@ -140,7 +141,7 @@ uint8_t Storage::i2c_receive(uint8_t len, uint8_t *data) data[pos] = TWDR; } - return pos + 1; + return pos; } /* @@ -148,19 +149,33 @@ uint8_t Storage::i2c_receive(uint8_t len, uint8_t *data) * Does not check for page boundaries yet. * Includes a complete I2C transaction. */ -uint8_t Storage::i2c_write(uint16_t pos, uint8_t len, uint8_t *data) +uint8_t Storage::i2c_write(uint8_t addrhi, uint8_t addrlo, uint8_t len, uint8_t *data) { uint8_t addr_buf[2]; + uint8_t num_tries; - addr_buf[0] = pos >> 8; - addr_buf[1] = pos & 0xff; + addr_buf[0] = addrhi; + addr_buf[1] = addrlo; - i2c_start_write(); - i2c_send(2, addr_buf); - i2c_send(len, data); - i2c_stop(); + for (num_tries = 0; num_tries < 16; num_tries++) { + if (num_tries > 0) + _delay_ms(1); + + if (i2c_start_write() != I2C_OK) + continue; + + if (i2c_send(2, addr_buf) != 2) + continue; + + if (i2c_send(len, data) != len) + continue; - return 0; // TODO proper return code to indicate write errors + i2c_stop(); + return I2C_OK; + } + + i2c_stop(); + return I2C_ERR; } /* @@ -168,26 +183,43 @@ uint8_t Storage::i2c_write(uint16_t pos, uint8_t len, uint8_t *data) * Does not check for page boundaries yet. * Includes a complete I2C transaction. */ -uint8_t Storage::i2c_read(uint16_t pos, uint8_t len, uint8_t *data) +uint8_t Storage::i2c_read(uint8_t addrhi, uint8_t addrlo, uint8_t len, uint8_t *data) { uint8_t addr_buf[2]; - addr_buf[0] = pos >> 8; - addr_buf[1] = pos & 0xff; + uint8_t num_tries; - i2c_start_write(); - i2c_send(2, addr_buf); - i2c_start_read(); - i2c_receive(len, data); - i2c_stop(); + addr_buf[0] = addrhi; + addr_buf[1] = addrlo; - return 0; // TODO proper return code to indicate read/write errors + for (num_tries = 0; num_tries < 16; num_tries++) { + if (num_tries > 0) + _delay_ms(1); + + if (i2c_start_write() != I2C_OK) + continue; + + if (i2c_send(2, addr_buf) != 2) + continue; + + if (i2c_start_read() != I2C_OK) + continue; + + if (i2c_receive(len, data) != len) + continue; + + i2c_stop(); + return I2C_OK; + } + + i2c_stop(); + return I2C_ERR; } void Storage::reset() { first_free_page = 0; num_anims = 0xff; - i2c_write(0, 1, &num_anims); // pretend the EEPROM was never written to + i2c_write(0, 0, 1, &num_anims); // pretend the EEPROM was never written to num_anims = 0; } @@ -199,21 +231,21 @@ bool Storage::hasData() return true; } -void Storage::load(uint16_t idx, uint8_t *data) +void Storage::load(uint8_t idx, uint8_t *data) { uint8_t page_offset; uint8_t header[2]; - i2c_read(1 + idx, 1, &page_offset); + i2c_read(0, 1 + idx, 1, &page_offset); - i2c_read(256 + (64 * (uint16_t)page_offset), 2, header); - i2c_read(256 + (64 * (uint16_t)page_offset), header[1] + 2, data); + i2c_read(1 + (page_offset / 8), (page_offset % 8) * 32, 2, header); + i2c_read(1 + (page_offset / 8), (page_offset % 8) * 32, header[1] + 2, data); } void Storage::save(uint8_t *data) { num_anims++; - i2c_write(0, 1, &num_anims); - i2c_write(num_anims, 1, &first_free_page); + i2c_write(0, 0, 1, &num_anims); + i2c_write(0, num_anims, 1, &first_free_page); append(data); } @@ -222,6 +254,6 @@ void Storage::append(uint8_t *data) // the header indicates the length of the data, but we really don't care // - it's easier to just write the whole page and skip the trailing // garbage when reading. - i2c_write(256 + (64 * (uint16_t)first_free_page), 64, data); + i2c_write(1 + (first_free_page / 8), (first_free_page % 8) * 32, 32, data); first_free_page++; } |