/* * Copyright © 2009 Keith Packard * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; version 2 of the License. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ #include "ao.h" #include "25lc1024.h" #define EE_BLOCK_SIZE ((uint16_t) (256)) #define EE_DEVICE_SIZE ((uint32_t) 128 * (uint32_t) 1024) /* Total bytes of available storage */ __xdata uint32_t ao_storage_total; /* Block size - device is erased in these units. At least 256 bytes */ __xdata uint32_t ao_storage_block; /* Byte offset of config block. Will be ao_storage_block bytes long */ __xdata uint32_t ao_storage_config; /* * Using SPI on USART 0, with P1_2 as the chip select */ #define EE_CS P1_2 #define EE_CS_INDEX 2 static __xdata uint8_t ao_ee_mutex; #define ao_ee_delay() do { \ _asm nop _endasm; \ _asm nop _endasm; \ _asm nop _endasm; \ } while(0) static void ao_ee_cs_low(void) { ao_ee_delay(); EE_CS = 0; ao_ee_delay(); } static void ao_ee_cs_high(void) { ao_ee_delay(); EE_CS = 1; ao_ee_delay(); } struct ao_ee_instruction { uint8_t instruction; uint8_t address[3]; } __xdata ao_ee_instruction; static void ao_ee_write_enable(void) { ao_ee_cs_low(); ao_ee_instruction.instruction = EE_WREN; ao_spi_send(&ao_ee_instruction, 1); ao_ee_cs_high(); } static uint8_t ao_ee_rdsr(void) { ao_ee_cs_low(); ao_ee_instruction.instruction = EE_RDSR; ao_spi_send(&ao_ee_instruction, 1); ao_spi_recv(&ao_ee_instruction, 1); ao_ee_cs_high(); return ao_ee_instruction.instruction; } static void ao_ee_wrsr(uint8_t status) { ao_ee_cs_low(); ao_ee_instruction.instruction = EE_WRSR; ao_ee_instruction.address[0] = status; ao_spi_send(&ao_ee_instruction, 2); ao_ee_cs_high(); } #define EE_BLOCK_NONE 0xffff static __xdata uint8_t ao_ee_data[EE_BLOCK_SIZE]; static __pdata uint16_t ao_ee_block = EE_BLOCK_NONE; static __pdata uint8_t ao_ee_block_dirty; /* Write the current block to the EEPROM */ static void ao_ee_write_block(void) { uint8_t status; status = ao_ee_rdsr(); if (status & (EE_STATUS_BP0|EE_STATUS_BP1|EE_STATUS_WPEN)) { status &= ~(EE_STATUS_BP0|EE_STATUS_BP1|EE_STATUS_WPEN); ao_ee_wrsr(status); } ao_ee_write_enable(); ao_ee_cs_low(); ao_ee_instruction.instruction = EE_WRITE; ao_ee_instruction.address[0] = ao_ee_block >> 8; ao_ee_instruction.address[1] = ao_ee_block; ao_ee_instruction.address[2] = 0; ao_spi_send(&ao_ee_instruction, 4); ao_spi_send(ao_ee_data, EE_BLOCK_SIZE); ao_ee_cs_high(); for (;;) { uint8_t status = ao_ee_rdsr(); if ((status & EE_STATUS_WIP) == 0) break; } } /* Read the current block from the EEPROM */ static void ao_ee_read_block(void) { ao_ee_cs_low(); ao_ee_instruction.instruction = EE_READ; ao_ee_instruction.address[0] = ao_ee_block >> 8; ao_ee_instruction.address[1] = ao_ee_block; ao_ee_instruction.address[2] = 0; ao_spi_send(&ao_ee_instruction, 4); ao_spi_recv(ao_ee_data, EE_BLOCK_SIZE); ao_ee_cs_high(); } static void ao_ee_flush_internal(void) { if (ao_ee_block_dirty) { ao_ee_write_block(); ao_ee_block_dirty = 0; } } static void ao_ee_fill(uint16_t block) { if (block != ao_ee_block) { ao_ee_flush_internal(); ao_ee_block = block; ao_ee_read_block(); } } uint8_t ao_storage_write(uint32_t pos, __xdata void *buf, uint16_t len) __reentrant { uint16_t block; uint16_t this_len; uint8_t this_off; if (pos >= ao_storage_total || pos + len > ao_storage_total) return 0; while (len) { /* Compute portion of transfer within * a single block */ this_off = pos; this_len = EE_BLOCK_SIZE - (uint16_t) this_off; block = (uint16_t) (pos >> 8); if (this_len > len) this_len = len; if (this_len & 0xff00) ao_panic(AO_PANIC_EE); /* Transfer the data */ ao_mutex_get(&ao_ee_mutex); { if (this_len != EE_BLOCK_SIZE) ao_ee_fill(block); else { ao_ee_flush_internal(); ao_ee_block = block; } memcpy(ao_ee_data + this_off, buf, this_len); ao_ee_block_dirty = 1; } ao_mutex_put(&ao_ee_mutex); /* See how much is left */ buf += this_len; len -= this_len; pos += this_len; } return 1; } uint8_t ao_storage_read(uint32_t pos, __xdata void *buf, uint16_t len) __reentrant { uint16_t block; uint16_t this_len; uint8_t this_off; if (pos >= ao_storage_total || pos + len > ao_storage_total) return 0; while (len) { /* Compute portion of transfer within * a single block */ this_off = pos; this_len = EE_BLOCK_SIZE - (uint16_t) this_off; block = (uint16_t) (pos >> 8); if (this_len > len) this_len = len; if (this_len & 0xff00) ao_panic(AO_PANIC_EE); /* Transfer the data */ ao_mutex_get(&ao_ee_mutex); { ao_ee_fill(block); memcpy(buf, ao_ee_data + this_off, this_len); } ao_mutex_put(&ao_ee_mutex); /* See how much is left */ buf += this_len; len -= this_len; pos += this_len; } return 1; } void ao_storage_flush(void) __reentrant { ao_mutex_get(&ao_ee_mutex); { ao_ee_flush_internal(); } ao_mutex_put(&ao_ee_mutex); } static void ee_dump(void) __reentrant { static __xdata uint8_t b; uint16_t block; uint8_t i; ao_cmd_hex(); block = ao_cmd_lex_i; if (ao_cmd_status != ao_cmd_success) return; i = 0; do { if ((i & 7) == 0) { if (i) putchar('\n'); ao_cmd_put16((uint16_t) i); } putchar(' '); ao_storage_read(((uint32_t) block << 8) | i, &b, 1); ao_cmd_put8(b); ++i; } while (i != 0); putchar('\n'); } static void ee_store(void) __reentrant { uint16_t block; uint8_t i; uint16_t len; static __xdata uint8_t b; uint32_t addr; ao_cmd_hex(); block = ao_cmd_lex_i; ao_cmd_hex(); i = ao_cmd_lex_i; addr = ((uint32_t) block << 8) | i; ao_cmd_hex(); len = ao_cmd_lex_i; if (ao_cmd_status != ao_cmd_success) return; while (len--) { ao_cmd_hex(); if (ao_cmd_status != ao_cmd_success) return; b = ao_cmd_lex_i; ao_storage_write(addr, &b, 1); addr++; } ao_storage_flush(); } __code struct ao_cmds ao_ee_cmds[] = { { 'e', ee_dump, "e Dump a block of EEPROM data" }, { 'w', ee_store, "w ... Write data to EEPROM" }, { 0, ee_store, NULL }, }; void ao_storage_setup(void) { if (ao_storage_total == 0) { ao_storage_total = EE_DEVICE_SIZE; ao_storage_block = EE_BLOCK_SIZE; ao_storage_config = EE_DEVICE_SIZE - EE_BLOCK_SIZE; } } /* * To initialize the chip, set up the CS line and * the SPI interface */ void ao_storage_init(void) { /* set up CS */ EE_CS = 1; P1DIR |= (1 << EE_CS_INDEX); P1SEL &= ~(1 << EE_CS_INDEX); ao_cmd_register(&ao_ee_cmds[0]); }