X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=drv%2Feeprom.c;h=f92091487ae0cc9daeb2fb7cf7bcbd210a2f8d1a;hb=HEAD;hp=e73e1f53fa412bd6c67b9dcc564d45030b9d51a7;hpb=8e90a9cdc1bf5a30c92edcc218e9cc16327d7d21;p=bertos.git diff --git a/drv/eeprom.c b/drv/eeprom.c deleted file mode 100755 index e73e1f53..00000000 --- a/drv/eeprom.c +++ /dev/null @@ -1,306 +0,0 @@ -/*! - * \file - * - * - * \version $Id$ - * - * \author Stefano Fedrigo - * - * \brief I2C eeprom driver - */ - -/* - * $Log$ - * Revision 1.1 2004/07/20 17:11:18 bernie - * Import into DevLib. - * - */ - -#include "eeprom.h" -#include /* cpu_to_be16() */ -#include -#include - -#include - - -/* 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) -{ - //TRACE; - - /* Do a loop on the select write sequence because if the - * eeprom is busy writing precedently sent data it will respond - * with NACK to the SLA_W control byte. In this case we have - * to try until the eeprom reply with an ACK. - */ - while (twi_start()) - { - TWDR = SLA_W | ((slave_addr & 0x5) << 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) -{ - //TRACE; - - if (twi_start()) - { - TWDR = SLA_R | ((slave_addr & 0x5) << 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) -{ - //TRACE; - - 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) -{ - //TRACE; - - 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) -{ - //TRACE; - - /* - * 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. - * - * \note No check is done for data crossing page - * boundaries. - */ -bool eeprom_write(e2addr_t addr, const void *buf, size_t count) -{ - // eeprom accepts address as big endian - addr = cpu_to_be16(addr); - - bool res = - twi_start_w(0) - && twi_send((uint8_t *)&addr, sizeof(addr)) - && twi_send(buf, count); - - twi_stop(); - - return res; -} - - -/*! - * 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) -{ - // eeprom accepts address as big endian - 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); - - 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; -} - - -/*! - * Initialize TWI module. - */ -void eeprom_init(void) -{ - cpuflags_t flags; - DISABLE_IRQSAVE(flags); - - DDRD |= BV(PORTD0) | BV(PORTD1); - PORTD |= BV(PORTD0) | BV(PORTD1); - - /* - * 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; - - ENABLE_IRQRESTORE(flags); -} - - -#ifdef _DEBUG - -void eeprom_test(void) -{ - static const char magic[] = "Humpty Dumpty"; - char buf[sizeof magic]; - - // Write something to EEPROM and read it back - eeprom_write(0, magic, sizeof magic); - eeprom_read(0, buf, sizeof buf); - kprintf("EEPROM read: %s\n", buf); -} - -#endif // _DEBUG -