+++ /dev/null
-/*!
- * \file
- * <!--
- * Copyright 2003, 2004 Develer S.r.l. (http://www.develer.com/)
- * All Rights Reserved.
- * -->
- *
- * \version $Id$
- *
- * \author Stefano Fedrigo <aleph@develer.com>
- * \author Bernardo Innocenti <bernie@develer.com>
- *
- * \brief Driver for the 24xx16 and 24xx256 I2C EEPROMS (implementation)
- *
- * \note This implementation is AVR specific.
- */
-
-/*
- * $Log$
- * Revision 1.7 2004/08/24 16:48:40 bernie
- * Note reason for including <macros.h>
- *
- * Revision 1.6 2004/08/24 14:27:20 bernie
- * Doxygen fix.
- *
- * Revision 1.5 2004/08/24 13:46:48 bernie
- * Include <macros.h>.
- *
- * Revision 1.4 2004/08/10 06:57:22 bernie
- * eeprom_erase(): New function.
- *
- * Revision 1.3 2004/07/29 22:57:09 bernie
- * Add 24LC16 support.
- *
- * Revision 1.2 2004/07/22 01:24:43 bernie
- * Document AVR dependency.
- *
- * Revision 1.1 2004/07/20 17:11:18 bernie
- * Import into DevLib.
- *
- */
-
-#include "eeprom.h"
-
-#include <mware/byteorder.h> /* cpu_to_be16() */
-#include <drv/kdebug.h>
-#include <hw.h>
-#include <macros.h> // MIN()
-
-#include <string.h> // memset()
-
-#include <avr/twi.h>
-
-
-/* Wait for TWINT flag set: bus is ready */
-#define WAIT_TWI_READY do {} while (!(TWCR & BV(TWINT)))
-
-/*! \name EEPROM control codes */
-/*@{*/
-#define SLA_W 0xA0
-#define SLA_R 0xA1
-/*@}*/
-
-
-/*!
- * Send START condition on the bus.
- *
- * \return true on success, false otherwise.
- */
-static bool twi_start(void)
-{
- TWCR = BV(TWINT) | BV(TWSTA) | BV(TWEN);
- WAIT_TWI_READY;
-
- if (TW_STATUS == TW_START || TW_STATUS == TW_REP_START)
- return true;
-
- DB(kprintf("!TW_(REP)START: %x\n", TWSR);)
- return false;
-}
-
-
-/*!
- * Send START condition and select slave for write.
- *
- * \return true on success, false otherwise.
- */
-static bool twi_start_w(uint8_t slave_addr)
-{
- ASSERT(slave_addr < 8);
-
- /*
- * Loop on the select write sequence: when the eeprom is busy
- * writing previously sent data it will reply to the SLA_W
- * control byte with a NACK. In this case, we must
- * keep trying until the eeprom responds with an ACK.
- */
- while (twi_start())
- {
- TWDR = SLA_W | (slave_addr << 1);
- TWCR = BV(TWINT) | BV(TWEN);
- WAIT_TWI_READY;
-
- if (TW_STATUS == TW_MT_SLA_ACK)
- return true;
- else if (TW_STATUS != TW_MT_SLA_NACK)
- {
- DB(kprintf("!TW_MT_SLA_(N)ACK: %x\n", TWSR);)
- break;
- }
- }
-
- return false;
-}
-
-
-/*!
- * Send START condition and select slave for read.
- *
- * \return true on success, false otherwise.
- */
-static bool twi_start_r(uint8_t slave_addr)
-{
- ASSERT(slave_addr < 8);
-
- if (twi_start())
- {
- TWDR = SLA_R | (slave_addr << 1);
- TWCR = BV(TWINT) | BV(TWEN);
- WAIT_TWI_READY;
-
- if (TW_STATUS == TW_MR_SLA_ACK)
- return true;
-
- DB(kprintf("!TW_MR_SLA_ACK: %x\n", TWSR);)
- }
-
- return false;
-}
-
-
-/*!
- * Send STOP condition.
- */
-static void twi_stop(void)
-{
- TWCR = BV(TWINT) | BV(TWEN) | BV(TWSTO);
-}
-
-
-/*!
- * Send a sequence of bytes in master transmitter mode
- * to the selected slave device through the TWI bus.
- *
- * \return true on success, false on error.
- */
-static bool twi_send(const uint8_t *buf, size_t count)
-{
- while (count--)
- {
- TWDR = *buf++;
- TWCR = BV(TWINT) | BV(TWEN);
- WAIT_TWI_READY;
- if (TW_STATUS != TW_MT_DATA_ACK)
- {
- DB(kprintf("!TW_MT_DATA_ACK: %x\n", TWSR);)
- return false;
- }
- }
-
- return true;
-}
-
-
-/*!
- * Receive a sequence of one or more bytes from the
- * selected slave device in master receive mode through
- * the TWI bus.
- *
- * Received data is placed in \c buf.
- *
- * \return true on success, false on error
- */
-static bool twi_recv(uint8_t *buf, size_t count)
-{
- /*
- * When reading the last byte the TWEA bit is not
- * set, and the eeprom should answer with NACK
- */
- while (count--)
- {
- TWCR = BV(TWINT) | BV(TWEN) | (count ? BV(TWEA) : 0);
- WAIT_TWI_READY;
-
- if (count)
- {
- if (TW_STATUS != TW_MR_DATA_ACK)
- {
- DB(kprintf("!TW_MR_DATA_ACK: %x\n", TWSR);)
- return false;
- }
- }
- else
- {
- if (TW_STATUS != TW_MR_DATA_NACK)
- {
- DB(kprintf("!TW_MR_DATA_NACK: %x\n", TWSR);)
- return false;
- }
- }
- *buf++ = TWDR;
- }
-
- return true;
-}
-
-/*!
- * Copy \c count bytes from buffer \c buf to
- * eeprom at address \c addr.
- */
-bool eeprom_write(e2addr_t addr, const void *buf, size_t count)
-{
- bool result = true;
- ASSERT(addr + count <= EEPROM_SIZE);
-
- while (count && result)
- {
- /*
- * Split write in multiple sequential mode operations that
- * don't cross page boundaries.
- */
- size_t size =
- MIN(count, (size_t)(EEPROM_BLKSIZE - (addr & (EEPROM_BLKSIZE - 1))));
-
- #if CONFIG_EEPROM_TYPE == EEPROM_24XX16
- /*
- * The 24LC16 uses the slave address as a 3-bit
- * block address.
- */
- uint8_t blk_addr = (uint8_t)((addr >> 8) & 0x07);
- uint8_t blk_offs = (uint8_t)addr;
-
- result =
- twi_start_w(blk_addr)
- && twi_send(&blk_offs, sizeof blk_offs)
- && twi_send(buf, size);
-
- #elif CONFIG_EEPROM_TYPE == EEPROM_24XX256
-
- // 24LC256 wants big-endian addresses
- uint16_t addr_be = cpu_to_be16(addr);
-
- result =
- twi_start_w(0)
- && twi_send((uint8_t *)&addr_be, sizeof addr_be)
- && twi_send(buf, size);
-
- #else
- #error Unknown device type
- #endif
-
- twi_stop();
-
- // DEBUG
- //kprintf("addr=%d, count=%d, size=%d, *#?=%d\n",
- // addr, count, size,
- // (EEPROM_BLKSIZE - (addr & (EEPROM_BLKSIZE - 1)))
- //);
-
- /* Update count and addr for next operation */
- count -= size;
- addr += size;
- buf = ((const char *)buf) + size;
- }
-
- return result;
-}
-
-
-/*!
- * Copy \c count bytes at address \c addr
- * from eeprom to RAM to buffer \c buf.
- */
-bool eeprom_read(e2addr_t addr, void *buf, size_t count)
-{
- ASSERT(addr + count <= EEPROM_SIZE);
-
-#if CONFIG_EEPROM_TYPE == EEPROM_24XX16
- /*
- * The 24LC16 uses the slave address as a 3-bit
- * block address.
- */
- uint8_t blk_addr = (uint8_t)((addr >> 8) & 0x07);
- uint8_t blk_offs = (uint8_t)addr;
-
- bool res =
- twi_start_w(blk_addr)
- && twi_send(&blk_offs, sizeof blk_offs)
- && twi_start_r(blk_addr)
- && twi_recv(buf, count);
-
-#elif CONFIG_EEPROM_TYPE == EEPROM_24XX256
-
- // 24LC256 wants big-endian addresses
- addr = cpu_to_be16(addr);
-
- bool res =
- twi_start_w(0)
- && twi_send((uint8_t *)&addr, sizeof(addr))
- && twi_start_r(0)
- && twi_recv(buf, count);
-#else
- #error Unknown device type
-#endif
-
- twi_stop();
-
- return res;
-}
-
-
-/*!
- * Write a single character \a c at address \a addr.
- */
-bool eeprom_write_char(e2addr_t addr, char c)
-{
- return eeprom_write(addr, &c, 1);
-}
-
-
-/*!
- * Read a single character at address \a addr.
- *
- * \return the requested character or -1 in case of failure.
- */
-int eeprom_read_char(e2addr_t addr)
-{
- char c;
-
- if (eeprom_read(addr, &c, 1))
- return c;
- else
- return -1;
-}
-
-
-/*!
- * Erase specified part of eeprom, writing 0xFF.
- *
- * \param addr starting address
- * \param count length of block to erase
- */
-void eeprom_erase(e2addr_t addr, size_t count)
-{
- uint8_t buf[EEPROM_BLKSIZE];
- memset(buf, 0xFF, sizeof buf);
-
- // Clear all but struct hw_info at start of eeprom
- while (count)
- {
- size_t size = MIN(count, sizeof buf);
- eeprom_write(addr, buf, size);
- addr += size;
- count -= size;
- }
-}
-
-
-/*!
- * Initialize TWI module.
- */
-void eeprom_init(void)
-{
- cpuflags_t flags;
- DISABLE_IRQSAVE(flags);
-
-#if defined(__AVR_ATmega64__)
- PORTD |= BV(PD0) | BV(PD1);
- DDRD |= BV(PD0) | BV(PD1);
-#elif defined(__AVR_ATmega8__)
- PORTC |= BV(PC4) | BV(PC5);
- DDRC |= BV(PC4) | BV(PC5);
-#else
- #error Unsupported architecture
-#endif
-
- /*
- * Set speed:
- * F = CLOCK_FREQ / (16 + 2*TWBR * 4^TWPS)
- */
- #define TWI_FREQ 300000 /* 300 kHz */
- #define TWI_PRESC 1 /* 4 ^ TWPS */
-
- TWBR = (CLOCK_FREQ / (2 * TWI_FREQ * TWI_PRESC)) - (8 / TWI_PRESC);
- TWSR = 0;
- TWCR = BV(TWEN);
-
- ENABLE_IRQRESTORE(flags);
-}
-
-
-#ifdef _DEBUG
-
-#include <string.h>
-
-void eeprom_test(void)
-{
- static const char magic[13] = "Humpty Dumpty";
- char buf[sizeof magic + 1];
- size_t i;
-
- // Write something to EEPROM using unaligned sequential writes
- for (i = 0; i < 42; ++i)
- eeprom_write(i * sizeof magic, magic, sizeof magic);
-
- // Read back with single-byte reads
- for (i = 0; i < 42 * sizeof magic; ++i)
- {
- eeprom_read(i, buf, 1);
- kprintf("EEPROM byte read: %c (%d)\n", buf[0], buf[0]);
- ASSERT(buf[0] == magic[i % sizeof magic]);
- }
-
- // Read back again using sequential reads
- for (i = 0; i < 42; ++i)
- {
- memset(buf, 0, sizeof buf);
- eeprom_read(i * sizeof magic, buf, sizeof magic);
- kprintf("EEPROM seq read @ 0x%x: '%s'\n", i * sizeof magic, buf);
- ASSERT(memcmp(buf, magic, sizeof magic) == 0);
- }
-}
-
-#endif // _DEBUG
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