Mouse code for the MacroRat
mbed-dev/targets/TARGET_NORDIC/TARGET_NRF5_SDK13/i2c_api.c
- Committer:
- sahilmgandhi
- Date:
- 2017-05-14
- Revision:
- 18:6a4db94011d3
File content as of revision 18:6a4db94011d3:
/* * Copyright (c) 2017 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_twi.h" #include "nrf_drv_common.h" #include "sdk_config.h" #include "app_util_platform.h" #include "nrf_gpio.h" #include "nrf_delay.h" // An arbitrary value used as the counter in loops waiting for given event // (e.g. STOPPED), needed to avoid infinite loops (and not involve any timers // or tickers). #define TIMEOUT_VALUE 1000 #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)]) #define TWI0_INSTANCE_INDEX 0 #define TWI1_INSTANCE_INDEX TWI0_INSTANCE_INDEX+TWI0_ENABLED typedef struct { bool initialized; uint32_t pselsda; uint32_t pselscl; nrf_twi_frequency_t frequency; bool start_twi; #if DEVICE_I2C_ASYNCH volatile bool active; uint8_t const *tx; size_t tx_length; uint8_t *rx; size_t rx_length; bool stop; volatile uint32_t events; void (*handler)(void); uint32_t evt_mask; #endif // DEVICE_I2C_ASYNCH } twi_info_t; static twi_info_t m_twi_info[TWI_COUNT]; static NRF_TWI_Type * const m_twi_instances[TWI_COUNT] = { #if TWI0_ENABLED NRF_TWI0, #endif #if TWI1_ENABLED NRF_TWI1, #endif }; 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 }; #ifdef NRF51 #define TWI_IRQ_PRIORITY APP_IRQ_PRIORITY_LOW #elif defined(NRF52) || defined(NRF52840_XXAA) #define TWI_IRQ_PRIORITY APP_IRQ_PRIORITY_LOWEST #endif #if DEVICE_I2C_ASYNCH static void start_asynch_rx(twi_info_t *twi_info, NRF_TWI_Type *twi) { if (twi_info->rx_length == 1 && twi_info->stop) { nrf_twi_shorts_set(twi, NRF_TWI_SHORT_BB_STOP_MASK); } else { nrf_twi_shorts_set(twi, NRF_TWI_SHORT_BB_SUSPEND_MASK); } nrf_twi_task_trigger(twi, NRF_TWI_TASK_STARTRX); } static void twi_irq_handler(uint8_t instance_idx) { twi_info_t *twi_info = &m_twi_info[instance_idx]; NRF_TWI_Type *twi = m_twi_instances[instance_idx]; if (nrf_twi_event_check(twi, NRF_TWI_EVENT_ERROR)) { nrf_twi_event_clear(twi, NRF_TWI_EVENT_ERROR); // In case of an error, force STOP. // The current transfer may be suspended (if it is RX), so it must be // resumed before the STOP task is triggered. nrf_twi_task_trigger(twi, NRF_TWI_TASK_RESUME); nrf_twi_task_trigger(twi, NRF_TWI_TASK_STOP); uint32_t errorsrc = nrf_twi_errorsrc_get_and_clear(twi); twi_info->events |= I2C_EVENT_ERROR; if (errorsrc & NRF_TWI_ERROR_ADDRESS_NACK) { twi_info->events |= I2C_EVENT_ERROR_NO_SLAVE; } if (errorsrc & NRF_TWI_ERROR_DATA_NACK) { twi_info->events |= I2C_EVENT_TRANSFER_EARLY_NACK; } } bool finished = false; if (nrf_twi_event_check(twi, NRF_TWI_EVENT_TXDSENT)) { nrf_twi_event_clear(twi, NRF_TWI_EVENT_TXDSENT); MBED_ASSERT(twi_info->tx_length > 0); --(twi_info->tx_length); // Send next byte if there is still something to be sent. if (twi_info->tx_length > 0) { nrf_twi_txd_set(twi, *(twi_info->tx)); ++(twi_info->tx); // It TX is done, start RX if requested. } else if (twi_info->rx_length > 0) { start_asynch_rx(twi_info, twi); // If there is nothing more to do, finalize the transfer. } else { if (twi_info->stop) { nrf_twi_task_trigger(twi, NRF_TWI_TASK_STOP); } else { nrf_twi_task_trigger(twi, NRF_TWI_TASK_SUSPEND); finished = true; } twi_info->events |= I2C_EVENT_TRANSFER_COMPLETE; } } if (nrf_twi_event_check(twi, NRF_TWI_EVENT_RXDREADY)) { nrf_twi_event_clear(twi, NRF_TWI_EVENT_RXDREADY); MBED_ASSERT(twi_info->rx_length > 0); *(twi_info->rx) = nrf_twi_rxd_get(twi); ++(twi_info->rx); --(twi_info->rx_length); if (twi_info->rx_length > 0) { // If more bytes should be received, resume the transfer // (in case the stop condition should be generated after the next // byte, change the shortcuts configuration first). if (twi_info->rx_length == 1 && twi_info->stop) { nrf_twi_shorts_set(twi, NRF_TWI_SHORT_BB_STOP_MASK); } nrf_twi_task_trigger(twi, NRF_TWI_TASK_RESUME); } else { // If all requested bytes were received, finalize the transfer. finished = true; twi_info->events |= I2C_EVENT_TRANSFER_COMPLETE; } } if (finished || nrf_twi_event_check(twi, NRF_TWI_EVENT_STOPPED) || (nrf_twi_int_enable_check(twi, NRF_TWI_INT_SUSPENDED_MASK) && nrf_twi_event_check(twi, NRF_TWI_EVENT_SUSPENDED))) { // There is no need to clear the STOPPED and SUSPENDED events here, // they will no longer generate the interrupt - see below. nrf_twi_shorts_set(twi, 0); // Disable all interrupt sources. nrf_twi_int_disable(twi, UINT32_MAX); twi_info->active = false; if (twi_info->handler) { twi_info->handler(); } } } #if TWI0_ENABLED static void irq_handler_twi0(void) { twi_irq_handler(TWI0_INSTANCE_INDEX); } #endif #if TWI1_ENABLED static void irq_handler_twi1(void) { twi_irq_handler(TWI1_INSTANCE_INDEX); } #endif static nrf_drv_irq_handler_t const m_twi_irq_handlers[TWI_COUNT] = { #if TWI0_ENABLED irq_handler_twi0, #endif #if TWI1_ENABLED irq_handler_twi1, #endif }; #endif // DEVICE_I2C_ASYNCH static void configure_twi_pin(uint32_t pin, nrf_gpio_pin_dir_t dir) { nrf_gpio_cfg(pin, dir, NRF_GPIO_PIN_INPUT_CONNECT, NRF_GPIO_PIN_PULLUP, NRF_GPIO_PIN_S0D1, NRF_GPIO_PIN_NOSENSE); } static void twi_clear_bus(twi_info_t *twi_info) { // Try to set SDA high, and check if no slave tries to drive it low. nrf_gpio_pin_set(twi_info->pselsda); configure_twi_pin(twi_info->pselsda, NRF_GPIO_PIN_DIR_OUTPUT); // In case SDA is low, make up to 9 cycles on SCL line to help the slave // that pulls SDA low release it. if (!nrf_gpio_pin_read(twi_info->pselsda)) { nrf_gpio_pin_set(twi_info->pselscl); configure_twi_pin(twi_info->pselscl, NRF_GPIO_PIN_DIR_OUTPUT); nrf_delay_us(4); for (int i = 0; i < 9; i++) { if (nrf_gpio_pin_read(twi_info->pselsda)) { break; } nrf_gpio_pin_clear(twi_info->pselscl); nrf_delay_us(4); nrf_gpio_pin_set(twi_info->pselscl); nrf_delay_us(4); } // Finally, generate STOP condition to put the bus into initial state. nrf_gpio_pin_clear(twi_info->pselsda); nrf_delay_us(4); nrf_gpio_pin_set(twi_info->pselsda); } } 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].pselsda == (uint32_t)sda && m_twi_info[i].pselscl == (uint32_t)scl) { TWI_IDX(obj) = i; TWI_INFO(obj)->frequency = NRF_TWI_FREQ_100K; i2c_reset(obj); return; } } for (i = 0; i < TWI_COUNT; ++i) { if (!m_twi_info[i].initialized) { TWI_IDX(obj) = i; twi_info_t *twi_info = TWI_INFO(obj); twi_info->initialized = true; twi_info->pselsda = (uint32_t)sda; twi_info->pselscl = (uint32_t)scl; twi_info->frequency = NRF_TWI_FREQ_100K; twi_info->start_twi = false; #if DEVICE_I2C_ASYNCH twi_info->active = false; #endif twi_clear_bus(twi_info); configure_twi_pin(twi_info->pselsda, NRF_GPIO_PIN_DIR_INPUT); configure_twi_pin(twi_info->pselscl, NRF_GPIO_PIN_DIR_INPUT); i2c_reset(obj); #if DEVICE_I2C_ASYNCH nrf_drv_common_per_res_acquire(m_twi_instances[i], m_twi_irq_handlers[i]); NVIC_SetVector(twi_handlers[i].IRQn, twi_handlers[i].vector); nrf_drv_common_irq_enable(twi_handlers[i].IRQn, TWI_IRQ_PRIORITY); #endif return; } } error("No available I2C peripheral\r\n"); } void i2c_reset(i2c_t *obj) { twi_info_t *twi_info = TWI_INFO(obj); NRF_TWI_Type *twi = m_twi_instances[TWI_IDX(obj)]; nrf_twi_disable(twi); nrf_twi_pins_set(twi, twi_info->pselscl, twi_info->pselsda); nrf_twi_frequency_set(twi, twi_info->frequency); nrf_twi_enable(twi); } int i2c_start(i2c_t *obj) { twi_info_t *twi_info = TWI_INFO(obj); #if DEVICE_I2C_ASYNCH if (twi_info->active) { return I2C_ERROR_BUS_BUSY; } #endif twi_info->start_twi = true; return 0; } int i2c_stop(i2c_t *obj) { NRF_TWI_Type *twi = m_twi_instances[TWI_IDX(obj)]; // The current transfer may be suspended (if it is RX), so it must be // resumed before the STOP task is triggered. nrf_twi_task_trigger(twi, NRF_TWI_TASK_RESUME); nrf_twi_task_trigger(twi, NRF_TWI_TASK_STOP); uint32_t remaining_time = TIMEOUT_VALUE; do { if (nrf_twi_event_check(twi, NRF_TWI_EVENT_STOPPED)) { return 0; } } while (--remaining_time); return 1; } void i2c_frequency(i2c_t *obj, int hz) { twi_info_t *twi_info = TWI_INFO(obj); NRF_TWI_Type *twi = m_twi_instances[TWI_IDX(obj)]; if (hz < 250000) { twi_info->frequency = NRF_TWI_FREQ_100K; } else if (hz < 400000) { twi_info->frequency = NRF_TWI_FREQ_250K; } else { twi_info->frequency = NRF_TWI_FREQ_400K; } nrf_twi_frequency_set(twi, twi_info->frequency); } static uint8_t twi_address(int i2c_address) { // The TWI peripheral requires 7-bit slave address (without R/W bit). return (i2c_address >> 1); } static void start_twi_read(NRF_TWI_Type *twi, int address) { nrf_twi_event_clear(twi, NRF_TWI_EVENT_STOPPED); nrf_twi_event_clear(twi, NRF_TWI_EVENT_RXDREADY); nrf_twi_event_clear(twi, NRF_TWI_EVENT_ERROR); (void)nrf_twi_errorsrc_get_and_clear(twi); nrf_twi_shorts_set(twi, NRF_TWI_SHORT_BB_SUSPEND_MASK); nrf_twi_address_set(twi, twi_address(address)); nrf_twi_task_trigger(twi, NRF_TWI_TASK_RESUME); nrf_twi_task_trigger(twi, NRF_TWI_TASK_STARTRX); } int i2c_read(i2c_t *obj, int address, char *data, int length, int stop) { // Zero-length RX transfers are not supported. Such transfers cannot // be easily achieved with TWI peripheral (some dirty tricks would be // required for this), and they are actually useless (TX can be used // to check if the address is acknowledged by a slave). MBED_ASSERT(length > 0); twi_info_t *twi_info = TWI_INFO(obj); #if DEVICE_I2C_ASYNCH if (twi_info->active) { return I2C_ERROR_BUS_BUSY; } #endif twi_info->start_twi = false; NRF_TWI_Type *twi = m_twi_instances[TWI_IDX(obj)]; start_twi_read(twi, address); int result = length; while (length > 0) { int byte_read_result = i2c_byte_read(obj, (stop && length == 1)); if (byte_read_result < 0) { // When an error occurs, return the number of bytes that have been // received successfully. result -= length; // Force STOP condition. stop = 1; break; } *data++ = (uint8_t)byte_read_result; --length; } if (stop) { (void)i2c_stop(obj); } return result; } static uint8_t twi_byte_write(NRF_TWI_Type *twi, uint8_t data) { nrf_twi_event_clear(twi, NRF_TWI_EVENT_TXDSENT); nrf_twi_event_clear(twi, NRF_TWI_EVENT_ERROR); nrf_twi_txd_set(twi, data); uint32_t remaining_time = TIMEOUT_VALUE; do { if (nrf_twi_event_check(twi, NRF_TWI_EVENT_TXDSENT)) { nrf_twi_event_clear(twi, NRF_TWI_EVENT_TXDSENT); return 1; // ACK received } if (nrf_twi_event_check(twi, NRF_TWI_EVENT_ERROR)) { nrf_twi_event_clear(twi, NRF_TWI_EVENT_ERROR); return 0; // some error occurred } } while (--remaining_time); return 2; // timeout; } static void start_twi_write(NRF_TWI_Type *twi, int address) { nrf_twi_event_clear(twi, NRF_TWI_EVENT_STOPPED); nrf_twi_event_clear(twi, NRF_TWI_EVENT_TXDSENT); nrf_twi_event_clear(twi, NRF_TWI_EVENT_ERROR); (void)nrf_twi_errorsrc_get_and_clear(twi); nrf_twi_shorts_set(twi, 0); nrf_twi_address_set(twi, twi_address(address)); nrf_twi_task_trigger(twi, NRF_TWI_TASK_RESUME); nrf_twi_task_trigger(twi, NRF_TWI_TASK_STARTTX); } int i2c_write(i2c_t *obj, int address, const char *data, int length, int stop) { twi_info_t *twi_info = TWI_INFO(obj); #if DEVICE_I2C_ASYNCH if (twi_info->active) { return I2C_ERROR_BUS_BUSY; } #endif twi_info->start_twi = false; NRF_TWI_Type *twi = m_twi_instances[TWI_IDX(obj)]; start_twi_write(twi, address); // Special case - transaction with no data. // It can be used to check if a slave acknowledges the address. if (length == 0) { nrf_twi_event_t event; if (stop) { event = NRF_TWI_EVENT_STOPPED; nrf_twi_task_trigger(twi, NRF_TWI_TASK_STOP); } else { event = NRF_TWI_EVENT_SUSPENDED; nrf_twi_event_clear(twi, event); nrf_twi_task_trigger(twi, NRF_TWI_TASK_SUSPEND); } uint32_t remaining_time = TIMEOUT_VALUE; do { if (nrf_twi_event_check(twi, event)) { break; } } while (--remaining_time); uint32_t errorsrc = nrf_twi_errorsrc_get_and_clear(twi); if (errorsrc & NRF_TWI_ERROR_ADDRESS_NACK) { if (!stop) { i2c_stop(obj); } return I2C_ERROR_NO_SLAVE; } return (remaining_time ? 0 : I2C_ERROR_BUS_BUSY); } int result = length; do { uint8_t byte_write_result = twi_byte_write(twi, (uint8_t)*data++); if (byte_write_result != 1) { if (byte_write_result == 0) { // Check what kind of error has been signaled by TWI. uint32_t errorsrc = nrf_twi_errorsrc_get_and_clear(twi); if (errorsrc & NRF_TWI_ERROR_ADDRESS_NACK) { result = I2C_ERROR_NO_SLAVE; } else { // Some other error - return the number of bytes that // have been sent successfully. result -= length; } } else { result = I2C_ERROR_BUS_BUSY; } // Force STOP condition. stop = 1; break; } --length; } while (length > 0); if (stop) { (void)i2c_stop(obj); } return result; } int i2c_byte_read(i2c_t *obj, int last) { NRF_TWI_Type *twi = m_twi_instances[TWI_IDX(obj)]; if (last) { nrf_twi_shorts_set(twi, NRF_TWI_SHORT_BB_STOP_MASK); } nrf_twi_task_trigger(twi, NRF_TWI_TASK_RESUME); uint32_t remaining_time = TIMEOUT_VALUE; do { if (nrf_twi_event_check(twi, NRF_TWI_EVENT_RXDREADY)) { nrf_twi_event_clear(twi, NRF_TWI_EVENT_RXDREADY); return nrf_twi_rxd_get(twi); } if (nrf_twi_event_check(twi, NRF_TWI_EVENT_ERROR)) { nrf_twi_event_clear(twi, NRF_TWI_EVENT_ERROR); return I2C_ERROR_NO_SLAVE; } } while (--remaining_time); return I2C_ERROR_BUS_BUSY; } int i2c_byte_write(i2c_t *obj, int data) { NRF_TWI_Type *twi = m_twi_instances[TWI_IDX(obj)]; twi_info_t *twi_info = TWI_INFO(obj); if (twi_info->start_twi) { twi_info->start_twi = false; if (data & 1) { start_twi_read(twi, data); } else { start_twi_write(twi, data); } return 1; } else { nrf_twi_task_trigger(twi, NRF_TWI_TASK_RESUME); // 0 - TWI signaled error (NAK is the only possibility here) // 1 - ACK received // 2 - timeout (clock stretched for too long?) return twi_byte_write(twi, (uint8_t)data); } } #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)hint; twi_info_t *twi_info = TWI_INFO(obj); if (twi_info->active) { return; } twi_info->active = true; twi_info->events = 0; twi_info->handler = (void (*)(void))handler; twi_info->evt_mask = event; twi_info->tx_length = tx_length; twi_info->tx = tx; twi_info->rx_length = rx_length; twi_info->rx = rx; twi_info->stop = stop; NRF_TWI_Type *twi = m_twi_instances[TWI_IDX(obj)]; nrf_twi_event_clear(twi, NRF_TWI_EVENT_TXDSENT); nrf_twi_event_clear(twi, NRF_TWI_EVENT_RXDREADY); nrf_twi_event_clear(twi, NRF_TWI_EVENT_STOPPED); nrf_twi_event_clear(twi, NRF_TWI_EVENT_SUSPENDED); nrf_twi_event_clear(twi, NRF_TWI_EVENT_ERROR); (void)nrf_twi_errorsrc_get_and_clear(twi); nrf_twi_address_set(twi, twi_address(address)); nrf_twi_task_trigger(twi, NRF_TWI_TASK_RESUME); // TX only, or TX + RX (after a repeated start). if (tx_length > 0) { nrf_twi_task_trigger(twi, NRF_TWI_TASK_STARTTX); nrf_twi_txd_set(twi, *(twi_info->tx)); ++(twi_info->tx); // RX only. } else if (rx_length > 0) { start_asynch_rx(twi_info, twi); // Both 'tx_length' and 'rx_length' are 0 - this case may be used // to test if the slave is presentand ready for transfer (by just // sending the address and checking if it is acknowledged). } else { nrf_twi_task_trigger(twi, NRF_TWI_TASK_STARTTX); if (stop) { nrf_twi_task_trigger(twi, NRF_TWI_TASK_STOP); } else { nrf_twi_task_trigger(twi, NRF_TWI_TASK_SUSPEND); nrf_twi_int_enable(twi, NRF_TWI_INT_SUSPENDED_MASK); } twi_info->events |= I2C_EVENT_TRANSFER_COMPLETE; } nrf_twi_int_enable(twi, NRF_TWI_INT_TXDSENT_MASK | NRF_TWI_INT_RXDREADY_MASK | NRF_TWI_INT_STOPPED_MASK | NRF_TWI_INT_ERROR_MASK); } uint32_t i2c_irq_handler_asynch(i2c_t *obj) { twi_info_t *twi_info = TWI_INFO(obj); return (twi_info->events & twi_info->evt_mask); } uint8_t i2c_active(i2c_t *obj) { twi_info_t *twi_info = TWI_INFO(obj); return twi_info->active; } void i2c_abort_asynch(i2c_t *obj) { i2c_reset(obj); } #endif // DEVICE_I2C_ASYNCH #endif // DEVICE_I2C