/*#*
*#* $Log$
+ *#* Revision 1.15 2005/01/06 16:09:40 aleph
+ *#* Split twi/eeprom functions from eeprom module in separate twi module
+ *#*
*#* Revision 1.14 2004/12/13 12:07:06 bernie
*#* DISABLE_IRQSAVE/ENABLE_IRQRESTORE: Convert to IRQ_SAVE_DISABLE/IRQ_RESTORE.
*#*
#include "eeprom.h"
-#include <drv/wdt.h>
-#include <mware/byteorder.h> /* cpu_to_be16() */
#include <debug.h>
-#include <hw.h>
-#include <cpu.h> // IRQ_SAVE_DISABLE(), IRQ_RESTORE()
#include <config.h> // CONFIG_EEPROM_VERIFY
#include <macros.h> // MIN()
+#include <drv/twi.h>
+#include <drv/wdt.h>
+#include <mware/byteorder.h> // cpu_to_be16()
#include <string.h> // memset()
-#include <avr/twi.h>
// Configuration sanity checks
#if !defined(CONFIG_EEPROM_VERIFY) || (CONFIG_EEPROM_VERIFY != 0 && CONFIG_EEPROM_VERIFY != 1)
#endif
-/* 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 void *_buf, size_t count)
-{
- const uint8_t *buf = (const uint8_t *)_buf;
-
- 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(void *_buf, size_t count)
-{
- uint8_t *buf = (uint8_t *)_buf;
-
- /*
- * 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.
*/
void eeprom_init(void)
{
- cpuflags_t flags;
- IRQ_SAVE_DISABLE(flags);
-
- /*
- * This is pretty useless according to AVR's datasheet,
- * but it helps us driving the TWI data lines on boards
- * where the bus pull-up resistors are missing. This is
- * probably due to some unwanted interaction between the
- * port pin and the TWI lines.
- */
-#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 100000 /* ~100 kHz */
- #define TWI_PRESC 1 /* 4 ^ TWPS */
-
- TWBR = (CLOCK_FREQ / (2 * TWI_FREQ * TWI_PRESC)) - (8 / TWI_PRESC);
- TWSR = 0;
- TWCR = BV(TWEN);
-
- IRQ_RESTORE(flags);
+ twi_init();
}
// Write something to EEPROM using unaligned sequential writes
for (i = 0; i < 42; ++i)
+ {
+ wdt_reset();
eeprom_write(i * sizeof magic, magic, sizeof magic);
+ }
// Read back with single-byte reads
for (i = 0; i < 42 * sizeof magic; ++i)
{
+ wdt_reset();
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)
{
+ wdt_reset();
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);
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