bool i2c_read(void *i2c, uint8_t device_addr,
uint8_t reg_addr, uint8_t len, uint8_t *buffer)
{
Twihs *twi = (Twihs *)i2c;
if (twi != TWIHS0) // sanity-check... todo: other instances
return false;
/*
printf("starting %d-byte i2c read from device 0x%02x register 0x%02x\r\n",
(int)len, (unsigned)device_addr, (unsigned)reg_addr);
*/
twi->TWIHS_MMR =
TWIHS_MMR_IADRSZ(1) |
TWIHS_MMR_MREAD |
TWIHS_MMR_DADR(device_addr);
twi->TWIHS_IADR = reg_addr;
twi->TWIHS_CR = TWIHS_CR_START;
for (int i = 0; i < len; i++)
{
//printf("waiting for byte %d to arrive...\r\n", i);
while (!(twi->TWIHS_SR & TWIHS_SR_RXRDY));
buffer[i] = twi->TWIHS_RHR;
//printf("done! got byte %d\r\n", i);
if (i == len - 2)
twi->TWIHS_CR = TWIHS_CR_STOP;
}
while (!(twi->TWIHS_SR & TWIHS_SR_TXCOMP));
//printf("done with twi read\r\n");
return true;
}
/**
* \brief Write multiple bytes to a TWIHS compatible slave device.
*
* \note This function will NOT return until all data has been written or error occurred.
*
* \param p_twihs Pointer to a TWIHS instance.
* \param p_packet Packet information and data (see \ref twihs_packet_t).
*
* \return TWIHS_SUCCESS if all bytes were written, error code otherwise.
*/
uint32_t twihs_master_write(Twihs *p_twihs, twihs_packet_t *p_packet)
{
uint32_t status, cnt = p_packet->length;
uint8_t *buffer = p_packet->buffer;
/* Check argument */
if (cnt == 0) {
return TWIHS_INVALID_ARGUMENT;
}
/* Set write mode, slave address and 3 internal address byte lengths */
p_twihs->TWIHS_MMR = 0;
p_twihs->TWIHS_MMR = TWIHS_MMR_DADR(p_packet->chip) |
((p_packet->addr_length << TWIHS_MMR_IADRSZ_Pos) &
TWIHS_MMR_IADRSZ_Msk);
/* Set internal address for remote chip */
p_twihs->TWIHS_IADR = 0;
p_twihs->TWIHS_IADR = twihs_mk_addr(p_packet->addr, p_packet->addr_length);
/* Send all bytes */
while (cnt > 0) {
status = p_twihs->TWIHS_SR;
if (status & TWIHS_SR_NACK) {
return TWIHS_RECEIVE_NACK;
}
if (!(status & TWIHS_SR_TXRDY)) {
continue;
}
p_twihs->TWIHS_THR = *buffer++;
cnt--;
}
while (1) {
status = p_twihs->TWIHS_SR;
if (status & TWIHS_SR_NACK) {
return TWIHS_RECEIVE_NACK;
}
if (status & TWIHS_SR_TXRDY) {
break;
}
}
p_twihs->TWIHS_CR = TWIHS_CR_STOP;
while (!(p_twihs->TWIHS_SR & TWIHS_SR_TXCOMP)) {
}
return TWIHS_SUCCESS;
}
/**
* \brief Read multiple bytes from a TWIHS compatible slave device.
*
* \note This function will NOT return until all data has been read or error occurs.
*
* \param p_twihs Pointer to a TWIHS instance.
* \param p_packet Packet information and data (see \ref twihs_packet_t).
*
* \return TWIHS_SUCCESS if all bytes were read, error code otherwise.
*/
uint32_t twihs_master_read(Twihs *p_twihs, twihs_packet_t *p_packet)
{
uint32_t status, cnt = p_packet->length;
uint8_t *buffer = p_packet->buffer;
uint32_t timeout = TWIHS_TIMEOUT;
/* Check argument */
if (cnt == 0) {
return TWIHS_INVALID_ARGUMENT;
}
/* Set read mode, slave address and 3 internal address byte lengths */
p_twihs->TWIHS_MMR = 0;
p_twihs->TWIHS_MMR = TWIHS_MMR_MREAD | TWIHS_MMR_DADR(p_packet->chip) |
((p_packet->addr_length << TWIHS_MMR_IADRSZ_Pos) &
TWIHS_MMR_IADRSZ_Msk);
/* Set internal address for remote chip */
p_twihs->TWIHS_IADR = 0;
p_twihs->TWIHS_IADR = twihs_mk_addr(p_packet->addr, p_packet->addr_length);
/* Send a START Condition */
p_twihs->TWIHS_CR = TWIHS_CR_START;
while (cnt > 0) {
status = p_twihs->TWIHS_SR;
if (status & TWIHS_SR_NACK) {
return TWIHS_RECEIVE_NACK;
}
if (!timeout--) {
return TWIHS_ERROR_TIMEOUT;
}
/* Last byte ? */
if (cnt == 1) {
p_twihs->TWIHS_CR = TWIHS_CR_STOP;
}
if (!(status & TWIHS_SR_RXRDY)) {
continue;
}
*buffer++ = p_twihs->TWIHS_RHR;
cnt--;
timeout = TWIHS_TIMEOUT;
}
while (!(p_twihs->TWIHS_SR & TWIHS_SR_TXCOMP)) {
}
p_twihs->TWIHS_SR;
return TWIHS_SUCCESS;
}
bool i2c_write(void *i2c, uint8_t device_addr,
uint8_t reg_addr, uint8_t len, uint8_t *buffer)
{
Twihs *twi = (Twihs *)i2c;
if (twi != TWIHS0) // sanity-check... todo: other instances
return false;
twi->TWIHS_MMR =
TWIHS_MMR_IADRSZ(1) |
TWIHS_MMR_DADR(device_addr);
twi->TWIHS_IADR = reg_addr;
//twi->TWIHS_CR = TWIHS_CR_START;
for (int i = 0; i < len; i++)
{
twi->TWIHS_THR = buffer[i];
while (!(twi->TWIHS_SR & TWIHS_SR_TXRDY));
}
twi->TWIHS_CR = TWIHS_CR_STOP;
while (!(twi->TWIHS_SR & TWIHS_SR_TXCOMP));
return true;
}
/**
* \ingroup freertos_twihs_peripheral_control_group
* \brief Initiate a completely asynchronous multi-byte read operation on an TWIHS
* peripheral.
*
* freertos_twihs_read_packet_async() is an ASF specific FreeRTOS driver function.
* It configures the TWIHS peripheral DMA controller (PDC) to read data from the
* TWIHS port, then returns. freertos_twihs_read_packet_async() does not wait for
* the reception to complete before returning.
*
* The FreeRTOS ASF TWIHS driver is initialized using a call to
* freertos_twihs_master_init(). The freertos_driver_parameters.options_flags
* parameter passed into the initialization function defines the driver behavior.
* freertos_twihs_read_packet_async() can only be used if the
* freertos_driver_parameters.options_flags parameter passed to the initialization
* function had the WAIT_RX_COMPLETE bit clear.
*
* freertos_twihs_read_packet_async() is an advanced function and readers are
* recommended to also reference the application note and examples that
* accompany the FreeRTOS ASF drivers. freertos_twihs_read_packet() is a version
* that does not exit until the PDC transfer is complete, but still allows other
* RTOS tasks to execute while the transmission is in progress.
*
* The FreeRTOS ASF driver both installs and handles the TWIHS PDC interrupts.
* Users do not need to concern themselves with interrupt handling, and must
* not install their own interrupt handler.
*
* \param p_twihs The handle to the TWIHS port returned by the
* freertos_twihs_master_init() call used to initialise the port.
* \param p_packet Structure that defines the TWIHS transfer parameters, such
* as the I2C chip being addressed, the destination for the data being read,
* and the number of bytes to read. twihs_packet_t is a standard ASF type (it
* is not FreeRTOS specific).
* \param block_time_ticks The FreeRTOS ASF TWIHS driver is initialized using a
* call to freertos_twihs_master_init(). The
* freertos_driver_parameters.options_flags parameter passed to the
* initialization function defines the driver behavior. If
* freertos_driver_parameters.options_flags had the USE_RX_ACCESS_MUTEX bit
* set, then the driver will only read from the TWIHS peripheral if it has
* first gained exclusive access to it. block_time_ticks specifies the
* maximum amount of time the driver will wait to get exclusive access
* before aborting the read operation. Other tasks will execute during any
* waiting time. block_time_ticks is specified in RTOS tick periods. To
* specify a block time in milliseconds, divide the milliseconds value by
* portTICK_RATE_MS, and pass the result in block_time_ticks.
* portTICK_RATE_MS is defined by FreeRTOS.
* \param notification_semaphore The RTOS task that calls the receive
* function exits the receive function as soon as the reception starts.
* The data being received by the PDC cannot normally be processed until
* after the reception has completed. The PDC interrupt (handled internally
* by the FreeRTOS ASF driver) 'gives' the semaphore when the PDC transfer
* completes. The notification_semaphore therefore provides a mechanism for
* the calling task to know when the PDC has read the requested number of
* bytes. The calling task can call standard FreeRTOS functions to block on
* the semaphore until the PDC interrupt occurs. Other RTOS tasks will
* execute while the the calling task is in the Blocked state. The
* semaphore must be created using the FreeRTOS vSemaphoreCreateBinary() API
* function before it is used as a parameter.
*
* \return ERR_INVALID_ARG is returned if an input parameter is invalid.
* ERR_TIMEOUT is returned if block_time_ticks passed before exclusive
* access to the TWIHS peripheral could be obtained. STATUS_OK is returned if
* the PDC was successfully configured to perform the TWIHS read operation.
*/
status_code_t freertos_twihs_read_packet_async(freertos_twihs_if p_twihs,
twihs_packet_t *p_packet, portTickType block_time_ticks,
xSemaphoreHandle notification_semaphore)
{
status_code_t return_value;
portBASE_TYPE twihs_index;
Twihs *twihs_base;
uint32_t internal_address = 0;
twihs_base = (Twihs *) p_twihs;
twihs_index = get_pdc_peripheral_details(all_twihs_definitions, MAX_TWIHS,
(void *) twihs_base);
/* Don't do anything unless a valid TWIHS pointer was used. */
if ((twihs_index < MAX_TWIHS) && (p_packet->length > 0)) {
/* Because the peripheral is half duplex, there is only one access mutex
and the rx uses the tx mutex. */
return_value = freertos_obtain_peripheral_access_mutex(
&(tx_dma_control[twihs_index]), &block_time_ticks);
if (return_value == STATUS_OK) {
/* Ensure Rx is already empty. */
twihs_read_byte(twihs_base);
/* Set read mode and slave address. */
twihs_base->TWIHS_MMR = 0;
twihs_base->TWIHS_MMR = TWIHS_MMR_MREAD | TWIHS_MMR_DADR(
p_packet->chip) |
((p_packet->addr_length <<
TWIHS_MMR_IADRSZ_Pos) &
TWIHS_MMR_IADRSZ_Msk);
/* Set internal address if any. */
if (p_packet->addr_length) {
internal_address = p_packet->addr [0];
if (p_packet->addr_length > 1) {
internal_address <<= 8;
internal_address |= p_packet->addr[1];
}
if (p_packet->addr_length > 2) {
internal_address <<= 8;
internal_address |= p_packet->addr[2];
}
}
twihs_base->TWIHS_IADR = internal_address;
if (p_packet->length <= 2) {
/* Do not handle errors for short packets in interrupt handler */
twihs_disable_interrupt(
all_twihs_definitions[twihs_index].peripheral_base_address,
IER_ERROR_INTERRUPTS);
/* Cannot use PDC transfer, use normal transfer */
uint8_t stop_sent = 0;
uint32_t cnt = p_packet->length;
uint32_t status;
uint8_t *buffer = p_packet->buffer;
uint32_t timeout_counter = 0;
/* Start the transfer. */
if (cnt == 1) {
twihs_base->TWIHS_CR = TWIHS_CR_START | TWIHS_CR_STOP;
stop_sent = 1;
} else {
twihs_base->TWIHS_CR = TWIHS_CR_START;
}
while (cnt > 0) {
status = twihs_base->TWIHS_SR;
if (status & TWIHS_SR_NACK) {
/* Re-enable interrupts */
twihs_enable_interrupt(
all_twihs_definitions[twihs_index].peripheral_base_address,
IER_ERROR_INTERRUPTS);
/* Release semaphore */
xSemaphoreGive(tx_dma_control[twihs_index].peripheral_access_mutex);
return TWIHS_RECEIVE_NACK;
}
/* Last byte ? */
if (cnt == 1 && !stop_sent) {
twihs_base->TWIHS_CR = TWIHS_CR_STOP;
stop_sent = 1;
}
if (!(status & TWIHS_SR_RXRDY)) {
if (++timeout_counter >= TWIHS_TIMEOUT_COUNTER) {
return_value = ERR_TIMEOUT;
break;
}
continue;
}
*buffer++ = twihs_base->TWIHS_RHR;
cnt--;
timeout_counter = 0;
}
timeout_counter = 0;
/* Wait for stop to be sent */
while (!(twihs_base->TWIHS_SR & TWIHS_SR_TXCOMP)) {
/* Check timeout condition. */
if (++timeout_counter >= TWIHS_TIMEOUT_COUNTER) {
return_value = ERR_TIMEOUT;
break;
}
}
/* Re-enable interrupts */
twihs_enable_interrupt(
all_twihs_definitions[twihs_index].peripheral_base_address,
IER_ERROR_INTERRUPTS);
/* Release semaphores */
xSemaphoreGive(tx_dma_control[twihs_index].peripheral_access_mutex);
} else {
/* Start the PDC reception. */
twihss[twihs_index].buffer = p_packet->buffer;
twihss[twihs_index].length = p_packet->length;
freertos_start_pdc_rx(&(rx_dma_control[twihs_index]),
p_packet->buffer, p_packet->length,
all_twihs_definitions[twihs_index].pdc_base_address,
notification_semaphore);
/* Start the transfer. */
twihs_base->TWIHS_CR = TWIHS_CR_START;
/* Catch the end of reception so the access mutex can be returned,
and the task notified (if it supplied a notification semaphore).
The interrupt can be enabled here because the ENDRX signal from the
PDC to the peripheral will have been de-asserted when the next
transfer was configured. */
twihs_enable_interrupt(twihs_base, TWIHS_IER_ENDRX);
return_value = freertos_optionally_wait_transfer_completion(
&(rx_dma_control[twihs_index]),
notification_semaphore,
block_time_ticks);
}
}
} else {
return_value = ERR_INVALID_ARG;
}
return return_value;
}
/**
* \ingroup freertos_twihs_peripheral_control_group
* \brief Initiate a completely asynchronous multi-byte write operation on a TWIHS
* peripheral.
*
* freertos_twihs_write_packet_async() is an ASF specific FreeRTOS driver function.
* It configures the TWIHS peripheral DMA controller (PDC) to transmit data on the
* TWIHS port, then returns. freertos_twihs_write_packet_async() does not wait for
* the transmission to complete before returning.
*
* The FreeRTOS TWIHS driver is initialized using a call to
* freertos_twihs_master_init(). The freertos_driver_parameters.options_flags
* parameter passed into the initialization function defines the driver behavior.
* freertos_twihs_write_packet_async() can only be used if the
* freertos_driver_parameters.options_flags parameter passed to the initialization
* function had the WAIT_TX_COMPLETE bit clear.
*
* freertos_twihs_write_packet_async() is an advanced function and readers are
* recommended to also reference the application note and examples that
* accompany the FreeRTOS ASF drivers. freertos_twihs_write_packet() is a version
* that does not exit until the PDC transfer is complete, but still allows other
* RTOS tasks to execute while the transmission is in progress.
*
* The FreeRTOS ASF driver both installs and handles the TWIHS PDC interrupts.
* Users do not need to concern themselves with interrupt handling, and must
* not install their own interrupt handler.
*
* \param p_twihs The handle to the TWIHS peripheral returned by the
* freertos_twihs_master_init() call used to initialise the peripheral.
* \param p_packet Structure that defines the TWIHS transfer parameters, such
* as the I2C chip being addressed, the source data location, and the number
* of bytes to transmit. twihs_packet_t is a standard ASF type (it is not
* FreeRTOS specific).
* \param block_time_ticks The FreeRTOS ASF TWIHS driver is initialized using a
* call to freertos_twihs_master_init(). The
* freertos_driver_parameters.options_flags parameter passed to the
* initialization function defines the driver behavior. If
* freertos_driver_parameters.options_flags had the USE_TX_ACCESS_MUTEX bit
* set, then the driver will only write to the TWIHS peripheral if it has
* first gained exclusive access to it. block_time_ticks specifies the
* maximum amount of time the driver will wait to get exclusive access
* before aborting the write operation. Other tasks will execute during any
* waiting time. block_time_ticks is specified in RTOS tick periods. To
* specify a block time in milliseconds, divide the milliseconds value by
* portTICK_RATE_MS, and pass the result in block_time_ticks.
* portTICK_RATE_MS is defined by FreeRTOS.
* \param notification_semaphore The RTOS task that calls the transmit
* function exits the transmit function as soon as the transmission starts.
* The data being transmitted by the PDC must not be modified until after
* the transmission has completed. The PDC interrupt (handled internally by
* the FreeRTOS ASF driver) 'gives' the semaphore when the PDC transfer
* completes. The notification_semaphore therefore provides a mechanism for
* the calling task to know when the PDC has finished accessing the data.
* The calling task can call standard FreeRTOS functions to block on the
* semaphore until the PDC interrupt occurs. Other RTOS tasks will execute
* while the the calling task is in the Blocked state. The semaphore must
* be created using the FreeRTOS vSemaphoreCreateBinary() API function
* before it is used as a parameter.
*
* \return ERR_INVALID_ARG is returned if an input parameter is invalid.
* ERR_TIMEOUT is returned if block_time_ticks passed before exclusive
* access to the TWIHS peripheral could be obtained. STATUS_OK is returned if
* the PDC was successfully configured to perform the TWIHS write operation.
*/
status_code_t freertos_twihs_write_packet_async(freertos_twihs_if p_twihs,
twihs_packet_t *p_packet, portTickType block_time_ticks,
xSemaphoreHandle notification_semaphore)
{
status_code_t return_value;
portBASE_TYPE twihs_index;
Twihs *twihs_base;
uint32_t internal_address = 0;
twihs_base = (Twihs *) p_twihs;
twihs_index = get_pdc_peripheral_details(all_twihs_definitions, MAX_TWIHS,
(void *) twihs_base);
/* Don't do anything unless a valid TWIHS pointer was used. */
if ((twihs_index < MAX_TWIHS) && (p_packet->length > 0)) {
return_value = freertos_obtain_peripheral_access_mutex(
&(tx_dma_control[twihs_index]), &block_time_ticks);
if (return_value == STATUS_OK) {
/* Set write mode and slave address. */
twihs_base->TWIHS_MMR = 0;
twihs_base->TWIHS_MMR = TWIHS_MMR_DADR(p_packet->chip) |
((p_packet->addr_length <<
TWIHS_MMR_IADRSZ_Pos) &
TWIHS_MMR_IADRSZ_Msk);
/* Set internal address if any. */
if (p_packet->addr_length > 0) {
internal_address = p_packet->addr[0];
if (p_packet->addr_length > 1) {
internal_address <<= 8;
internal_address |= p_packet->addr[1];
}
if (p_packet->addr_length > 2) {
internal_address <<= 8;
internal_address |= p_packet->addr[2];
}
}
twihs_base->TWIHS_IADR = internal_address;
if (p_packet->length == 1) {
uint32_t status;
uint32_t timeout_counter = 0;
/* Do not handle errors for short packets in interrupt handler */
twihs_disable_interrupt(
all_twihs_definitions[twihs_index].peripheral_base_address,
IER_ERROR_INTERRUPTS);
/* Send start condition */
twihs_base->TWIHS_THR = *((uint8_t*)(p_packet->buffer));
while (1) {
status = twihs_base->TWIHS_SR;
if (status & TWIHS_SR_NACK) {
/* Re-enable interrupts */
twihs_enable_interrupt(
all_twihs_definitions[twihs_index].peripheral_base_address,
IER_ERROR_INTERRUPTS);
/* Release semaphore */
xSemaphoreGive(tx_dma_control[twihs_index].peripheral_access_mutex);
return TWIHS_RECEIVE_NACK;
}
if (status & TWIHS_SR_TXRDY) {
break;
}
/* Check timeout condition. */
if (++timeout_counter >= TWIHS_TIMEOUT_COUNTER) {
return_value = ERR_TIMEOUT;
break;
}
}
twihs_base->TWIHS_CR = TWIHS_CR_STOP;
/* Wait for TX complete */
while (!(twihs_base->TWIHS_SR & TWIHS_SR_TXCOMP)) {
/* Check timeout condition. */
if (++timeout_counter >= TWIHS_TIMEOUT_COUNTER) {
return_value = ERR_TIMEOUT;
break;
}
}
/* Re-enable interrupts */
twihs_enable_interrupt(
all_twihs_definitions[twihs_index].peripheral_base_address,
IER_ERROR_INTERRUPTS);
/* Release semaphores */
xSemaphoreGive(tx_dma_control[twihs_index].peripheral_access_mutex);
} else {
twihss[twihs_index].buffer = p_packet->buffer;
twihss[twihs_index].length = p_packet->length;
freertos_start_pdc_tx(&(tx_dma_control[twihs_index]),
p_packet->buffer, p_packet->length,
all_twihs_definitions[twihs_index].pdc_base_address,
notification_semaphore);
/* Catch the end of transmission so the access mutex can be
returned, and the task notified (if it supplied a notification
semaphore). The interrupt can be enabled here because the ENDTX
signal from the PDC to the peripheral will have been de-asserted when
the next transfer was configured. */
twihs_enable_interrupt(twihs_base, TWIHS_IER_ENDTX);
return_value = freertos_optionally_wait_transfer_completion(
&(tx_dma_control[twihs_index]),
notification_semaphore,
block_time_ticks);
}
}
} else {
return_value = ERR_INVALID_ARG;
}
return return_value;
}
