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AT91SAM7A3. I2C reading through write works, tested on 24AA IC. 

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@4837 35acf78f-673a-0410-8e92-d51de3d6d3f4
This commit is contained in:
barthess 2012-11-26 16:15:49 +00:00
parent a435774306
commit 8a12a3fb34
1 changed files with 72 additions and 18 deletions
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88
os/hal/platforms/AT91SAM7/i2c_lld.c
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@ -307,10 +307,74 @@ msg_t i2c_lld_master_receive_timeout(I2CDriver *i2cp, i2caddr_t addr,
AT91C_BASE_TWI->TWI_IER = AT91C_TWI_RXRDY | AT91C_TWI_NACK;
/* In single data byte master read or write, the START and STOP must both be set. */
uint32_t cr = AT91C_TWI_START;
if (rxbytes == 1)
cr |= AT91C_TWI_STOP;
AT91C_BASE_TWI->TWI_CR = cr;
AT91C_BASE_TWI->TWI_CR = AT91C_TWI_STOP | AT91C_TWI_START;
else
AT91C_BASE_TWI->TWI_CR = AT91C_TWI_START;
/* Waits for the operation completion.*/
i2cp->thread = chThdSelf();
chSchGoSleepS(THD_STATE_SUSPENDED);
return chThdSelf()->p_u.rdymsg;
}
/**
* @brief Read data via the I2C bus as master using internal slave addressing.
* @details Address bytes must be written in special purpose SAM7 registers.
*
* @param[in] i2cp pointer to the @p I2CDriver object
* @param[in] addr slave device address
* @param[in] txbuf pointer to the transmit buffer
* @param[in] txbytes number of bytes to be transmitted
* @param[out] rxbuf pointer to the receive buffer
* @param[in] rxbytes number of bytes to be received
* @param[in] timeout this value is ignored on SAM7 platform.
* .
* @return The operation status.
* @retval RDY_OK if the function succeeded.
* @retval RDY_RESET if one or more I2C errors occurred, the errors can
* be retrieved using @p i2cGetErrors().
*
* @notapi
*/
msg_t i2c_lld_transceive_timeout(I2CDriver *i2cp, i2caddr_t addr,
const uint8_t *txbuf, size_t txbytes,
uint8_t *rxbuf, size_t rxbytes,
systime_t timeout) {
(void)timeout;
/* delete trash from RHR*/
volatile uint32_t fake;
fake = AT91C_BASE_TWI->TWI_RHR;
(void)fake;
/* Initializes driver fields.*/
i2cp->rxbuf = rxbuf;
i2cp->rxbytes = rxbytes;
/* tune master mode register */
AT91C_BASE_TWI->TWI_MMR = 0;
AT91C_BASE_TWI->TWI_MMR |= (addr << 16) | (txbytes << 8) | AT91C_TWI_MREAD;
/* store internal slave address in TWI_IADR registers */
AT91C_BASE_TWI->TWI_IADR = 0;
while (txbytes > 0){
AT91C_BASE_TWI->TWI_IADR = (AT91C_BASE_TWI->TWI_IADR << 8);
AT91C_BASE_TWI->TWI_IADR |= *(txbuf++);
txbytes--;
}
/* enable just needed interrupts */
AT91C_BASE_TWI->TWI_IER = AT91C_TWI_RXRDY | AT91C_TWI_NACK;
/* Internal address of I2C slave was set in special Atmel registers.
* Now we must call read function. The I2C cell automatically sends
* bytes from IADR register to bus and issues repeated start. */
if (rxbytes == 1)
AT91C_BASE_TWI->TWI_CR = AT91C_TWI_STOP | AT91C_TWI_START;
else
AT91C_BASE_TWI->TWI_CR = AT91C_TWI_START;
/* Waits for the operation completion.*/
i2cp->thread = chThdSelf();
@ -346,24 +410,14 @@ msg_t i2c_lld_master_transmit_timeout(I2CDriver *i2cp, i2caddr_t addr,
(void)timeout;
/* SAM7 specific check */
chDbgCheck(((rxbytes == 0) || ((txbytes > 0) && (txbytes < 4) && (rxbuf != NULL))),
chDbgCheck(((rxbytes == 0) ||
((txbytes > 0) && (txbytes < 4) && (rxbuf != NULL))),
"i2c_lld_master_transmit_timeout");
/* prepare to read through write operation */
if (rxbytes > 0){
AT91C_BASE_TWI->TWI_MMR |= txbytes << 8;
/* store internal slave address in TWI_IADR registers */
AT91C_BASE_TWI->TWI_IADR = 0;
while (txbytes > 0){
AT91C_BASE_TWI->TWI_IADR = (AT91C_BASE_TWI->TWI_IADR << 8);
AT91C_BASE_TWI->TWI_IADR |= *(txbuf++);
txbytes--;
}
/* Internal address of I2C slave was set in special Atmel registers.
* Now we must call read function. The I2C cell automatically sends
* bytes from IADR register to bus and issues repeated start. */
return i2c_lld_master_receive_timeout(i2cp, addr, rxbuf, rxbytes, timeout);
return i2c_lld_transceive_timeout(i2cp, addr, txbuf, txbytes, rxbuf,
rxbytes, timeout);
}
else{
if (txbytes == 1){