mbed-os/targets/TARGET_NORDIC/TARGET_NRF5/i2c_api.c

330 lines
9.1 KiB
C

/*
* Copyright (c) 2013 Nordic Semiconductor ASA
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this list
* of conditions and the following disclaimer.
*
* 2. Redistributions in binary form, except as embedded into a Nordic Semiconductor ASA
* integrated circuit in a product or a software update for such product, must reproduce
* the above copyright notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of Nordic Semiconductor ASA nor the names of its contributors may be
* used to endorse or promote products derived from this software without specific prior
* written permission.
*
* 4. This software, with or without modification, must only be used with a
* Nordic Semiconductor ASA integrated circuit.
*
* 5. Any software provided in binary or object form under this license must not be reverse
* engineered, decompiled, modified and/or disassembled.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include "i2c_api.h"
#if DEVICE_I2C
#include "mbed_assert.h"
#include "mbed_error.h"
#include "nrf_drv_twi.h"
#include "app_util_platform.h"
#if DEVICE_I2C_ASYNCH
#define TWI_IDX(obj) ((obj)->i2c.twi_idx)
#else
#define TWI_IDX(obj) ((obj)->twi_idx)
#endif
#define TWI_INFO(obj) (&m_twi_info[TWI_IDX(obj)])
typedef struct {
bool initialized;
nrf_drv_twi_config_t config;
volatile bool transfer_finished;
#if DEVICE_I2C_ASYNCH
volatile uint32_t events;
void (*handler)(void);
uint32_t event_mask;
#endif
} twi_info_t;
static twi_info_t m_twi_info[TWI_COUNT];
static nrf_drv_twi_t const m_twi_instances[TWI_COUNT] = {
#if TWI0_ENABLED
NRF_DRV_TWI_INSTANCE(0),
#endif
#if TWI1_ENABLED
NRF_DRV_TWI_INSTANCE(1),
#endif
};
static void twi_event_handler(nrf_drv_twi_evt_t const *event, void *context)
{
twi_info_t * twi_info = TWI_INFO((i2c_t *)context);
twi_info->transfer_finished = true;
#if DEVICE_I2C_ASYNCH
switch (event->type) {
case NRF_DRV_TWI_EVT_DONE:
twi_info->events |= I2C_EVENT_TRANSFER_COMPLETE;
break;
case NRF_DRV_TWI_EVT_ADDRESS_NACK:
twi_info->events |= I2C_EVENT_ERROR_NO_SLAVE;
break;
case NRF_DRV_TWI_EVT_DATA_NACK:
twi_info->events |= I2C_EVENT_ERROR;
break;
}
if (twi_info->handler) {
twi_info->handler();
}
#endif // DEVICE_I2C_ASYNCH
}
static uint8_t twi_address(int i2c_address)
{
// The TWI driver requires 7-bit slave address (without R/W bit).
return (i2c_address >> 1);
}
void SPI0_TWI0_IRQHandler(void);
void SPI1_TWI1_IRQHandler(void);
static const peripheral_handler_desc_t twi_handlers[TWI_COUNT] =
{
#if TWI0_ENABLED
{
SPI0_TWI0_IRQn,
(uint32_t) SPI0_TWI0_IRQHandler
},
#endif
#if TWI1_ENABLED
{
SPI1_TWI1_IRQn,
(uint32_t) SPI1_TWI1_IRQHandler
}
#endif
};
void i2c_init(i2c_t *obj, PinName sda, PinName scl)
{
int i;
for (i = 0; i < TWI_COUNT; ++i) {
if (m_twi_info[i].initialized &&
m_twi_info[i].config.sda == (uint32_t)sda &&
m_twi_info[i].config.scl == (uint32_t)scl) {
TWI_IDX(obj) = i;
TWI_INFO(obj)->config.frequency = NRF_TWI_FREQ_100K;
i2c_reset(obj);
return;
}
}
nrf_drv_twi_config_t const config = {
.scl = scl,
.sda = sda,
.frequency = NRF_TWI_FREQ_100K,
#ifdef NRF51
.interrupt_priority = APP_IRQ_PRIORITY_LOW
#elif defined(NRF52)
.interrupt_priority = APP_IRQ_PRIORITY_LOWEST
#endif
};
for (i = 0; i < TWI_COUNT; ++i) {
if (!m_twi_info[i].initialized) {
NVIC_SetVector(twi_handlers[i].IRQn, twi_handlers[i].vector);
nrf_drv_twi_t const *twi = &m_twi_instances[i];
ret_code_t ret_code =
nrf_drv_twi_init(twi, &config, twi_event_handler, obj);
if (ret_code == NRF_SUCCESS) {
TWI_IDX(obj) = i;
TWI_INFO(obj)->initialized = true;
TWI_INFO(obj)->config = config;
nrf_drv_twi_enable(twi);
return;
}
}
}
// No available peripheral
error("No available I2C peripheral\r\n");
}
void i2c_reset(i2c_t *obj)
{
twi_info_t *twi_info = TWI_INFO(obj);
nrf_drv_twi_t const *twi = &m_twi_instances[TWI_IDX(obj)];
nrf_drv_twi_uninit(twi);
nrf_drv_twi_init(twi, &twi_info->config, twi_event_handler, obj);
nrf_drv_twi_enable(twi);
}
int i2c_start(i2c_t *obj)
{
(void)obj;
return -1; // Not implemented.
}
int i2c_stop(i2c_t *obj)
{
(void)obj;
return -1; // Not implemented.
}
void i2c_frequency(i2c_t *obj, int hz)
{
twi_info_t *twi_info = TWI_INFO(obj);
nrf_drv_twi_t const *twi = &m_twi_instances[TWI_IDX(obj)];
if (hz < 250000) {
twi_info->config.frequency = NRF_TWI_FREQ_100K;
} else if (hz < 400000) {
twi_info->config.frequency = NRF_TWI_FREQ_250K;
} else {
twi_info->config.frequency = NRF_TWI_FREQ_400K;
}
nrf_twi_frequency_set(twi->reg.p_twi, twi_info->config.frequency);
}
int i2c_read(i2c_t *obj, int address, char *data, int length, int stop)
{
(void)stop;
twi_info_t *twi_info = TWI_INFO(obj);
nrf_drv_twi_t const *twi = &m_twi_instances[TWI_IDX(obj)];
twi_info->transfer_finished = false;
ret_code_t ret_code = nrf_drv_twi_rx(twi, twi_address(address),
(uint8_t *)data, length);
if (ret_code != NRF_SUCCESS) {
return 0;
}
while (!twi_info->transfer_finished) {}
return nrf_drv_twi_data_count_get(twi);
}
int i2c_write(i2c_t *obj, int address, const char *data, int length, int stop)
{
twi_info_t *twi_info = TWI_INFO(obj);
nrf_drv_twi_t const *twi = &m_twi_instances[TWI_IDX(obj)];
twi_info->transfer_finished = false;
ret_code_t ret_code = nrf_drv_twi_tx(twi, twi_address(address),
(uint8_t const *)data, length, (stop == 0));
if (ret_code != NRF_SUCCESS) {
return 0;
}
while (!twi_info->transfer_finished) {}
return nrf_drv_twi_data_count_get(twi);
}
int i2c_byte_read(i2c_t *obj, int last)
{
(void)obj;
(void)last;
return -1; // Not implemented.
}
int i2c_byte_write(i2c_t *obj, int data)
{
(void)obj;
(void)data;
return -1; // Not implemented.
}
#if DEVICE_I2C_ASYNCH
void i2c_transfer_asynch(i2c_t *obj, const void *tx, size_t tx_length,
void *rx, size_t rx_length, uint32_t address,
uint32_t stop, uint32_t handler,
uint32_t event, DMAUsage hint)
{
(void)stop;
(void)hint;
if (i2c_active(obj)) {
return;
}
if ((tx_length == 0) && (rx_length == 0)) {
return;
}
twi_info_t *twi_info = TWI_INFO(obj);
twi_info->events = 0;
twi_info->handler = (void (*)(void))handler;
twi_info->event_mask = event;
uint8_t twi_addr = twi_address(address);
nrf_drv_twi_t const *twi = &m_twi_instances[TWI_IDX(obj)];
if ((tx_length > 0) && (rx_length == 0)) {
nrf_drv_twi_xfer_desc_t const xfer =
NRF_DRV_TWI_XFER_DESC_TX(twi_addr, (uint8_t *)tx, tx_length);
nrf_drv_twi_xfer(twi, &xfer,
stop ? 0 : NRF_DRV_TWI_FLAG_TX_NO_STOP);
}
else if ((tx_length == 0) && (rx_length > 0)) {
nrf_drv_twi_xfer_desc_t const xfer =
NRF_DRV_TWI_XFER_DESC_RX(twi_addr, rx, rx_length);
nrf_drv_twi_xfer(twi, &xfer, 0);
}
else if ((tx_length > 0) && (rx_length > 0)) {
nrf_drv_twi_xfer_desc_t const xfer =
NRF_DRV_TWI_XFER_DESC_TXRX(twi_addr,
(uint8_t *)tx, tx_length, rx, rx_length);
nrf_drv_twi_xfer(twi, &xfer, 0);
}
}
uint32_t i2c_irq_handler_asynch(i2c_t *obj)
{
twi_info_t *twi_info = TWI_INFO(obj);
return (twi_info->events & twi_info->event_mask);
}
uint8_t i2c_active(i2c_t *obj)
{
nrf_drv_twi_t const *twi = &m_twi_instances[TWI_IDX(obj)];
return nrf_drv_twi_is_busy(twi);
}
void i2c_abort_asynch(i2c_t *obj)
{
i2c_reset(obj);
}
#endif // DEVICE_I2C_ASYNCH
#endif // DEVICE_I2C