/** * Copyright (c) 2015 - 2018, 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 form under this license must not be reverse * engineered, decompiled, modified and/or disassembled. * * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA 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 "sdk_common.h" #if NRF_MODULE_ENABLED(NRF_TWI_MNGR) #include "nrf_twi_mngr.h" #include "nrf_assert.h" #include "app_util_platform.h" typedef volatile struct { bool transaction_in_progress; uint8_t transaction_result; } nrf_twi_mngr_cb_data_t; static ret_code_t start_transfer(nrf_twi_mngr_t const * p_nrf_twi_mngr) { ASSERT(p_nrf_twi_mngr != NULL); // Pointer for cleaner code. nrf_twi_mngr_cb_t * p_cb = p_nrf_twi_mngr->p_nrf_twi_mngr_cb; // [use a local variable to avoid using two volatile variables in one // expression] uint8_t current_transfer_idx = p_cb->current_transfer_idx; nrf_twi_mngr_transfer_t const * p_transfer = &p_cb->p_current_transaction->p_transfers[current_transfer_idx]; uint8_t address = NRF_TWI_MNGR_OP_ADDRESS(p_transfer->operation); nrf_drv_twi_xfer_desc_t xfer_desc; uint32_t flags; xfer_desc.address = address; xfer_desc.p_primary_buf = p_transfer->p_data; xfer_desc.primary_length = p_transfer->length; /* If it is possible try to bind two transfers together. They can be combined if: * - there is no stop condition after current transfer. * - current transfer is TX. * - there is at least one more transfer in the transaction. * - address of next transfer is the same as current transfer. */ if ((p_transfer->flags & NRF_TWI_MNGR_NO_STOP) && !NRF_TWI_MNGR_IS_READ_OP(p_transfer->operation) && // Adding 1 to check if next transfer is from the same transaction. ((current_transfer_idx + 1) < p_cb->p_current_transaction->number_of_transfers) && (NRF_TWI_MNGR_OP_ADDRESS(p_transfer->operation) == NRF_TWI_MNGR_OP_ADDRESS(p_cb->p_current_transaction-> p_transfers[current_transfer_idx + 1].operation))) { nrf_twi_mngr_transfer_t const * p_second_transfer = &p_cb->p_current_transaction->p_transfers[current_transfer_idx + 1]; xfer_desc.p_secondary_buf = p_second_transfer->p_data; xfer_desc.secondary_length = p_second_transfer->length; xfer_desc.type = NRF_TWI_MNGR_IS_READ_OP(p_second_transfer->operation) ? NRF_DRV_TWI_XFER_TXRX : NRF_DRV_TWI_XFER_TXTX; flags = (p_second_transfer->flags & NRF_TWI_MNGR_NO_STOP) ? NRF_DRV_TWI_FLAG_TX_NO_STOP : 0; p_cb->current_transfer_idx++; } else { xfer_desc.type = NRF_TWI_MNGR_IS_READ_OP(p_transfer->operation) ? NRF_DRV_TWI_XFER_RX : NRF_DRV_TWI_XFER_TX; xfer_desc.p_secondary_buf = NULL; xfer_desc.secondary_length = 0; flags = (p_transfer->flags & NRF_TWI_MNGR_NO_STOP) ? NRF_DRV_TWI_FLAG_TX_NO_STOP : 0; } return nrf_drv_twi_xfer(&p_nrf_twi_mngr->twi, &xfer_desc, flags); } static void transaction_end_signal(nrf_twi_mngr_t const * p_nrf_twi_mngr, ret_code_t result) { ASSERT(p_nrf_twi_mngr != NULL); if (p_nrf_twi_mngr->p_nrf_twi_mngr_cb->p_current_transaction->callback) { // [use a local variable to avoid using two volatile variables in one // expression] void * p_user_data = p_nrf_twi_mngr->p_nrf_twi_mngr_cb->p_current_transaction->p_user_data; p_nrf_twi_mngr->p_nrf_twi_mngr_cb->p_current_transaction->callback(result, p_user_data); } } static void twi_event_handler(nrf_drv_twi_evt_t const * p_event, void * p_context); // This function starts pending transaction if there is no current one or // when 'switch_transaction' parameter is set to true. It is important to // switch to new transaction without setting 'p_nrf_twi_mngr->p_current_transaction' // to NULL in between, since this pointer is used to check idle status - see // 'nrf_twi_mngr_is_idle()'. static void start_pending_transaction(nrf_twi_mngr_t const * p_nrf_twi_mngr, bool switch_transaction) { ASSERT(p_nrf_twi_mngr != NULL); // Pointer for cleaner code. nrf_twi_mngr_cb_t * p_cb = p_nrf_twi_mngr->p_nrf_twi_mngr_cb; for (;;) { bool start_transaction = false; CRITICAL_REGION_ENTER(); if (switch_transaction || nrf_twi_mngr_is_idle(p_nrf_twi_mngr)) { if (nrf_queue_pop(p_nrf_twi_mngr->p_queue, (void *)(&p_cb->p_current_transaction)) == NRF_SUCCESS) { start_transaction = true; } else { p_cb->p_current_transaction = NULL; } } CRITICAL_REGION_EXIT(); if (!start_transaction) { return; } else { ret_code_t result; nrf_drv_twi_config_t const * p_instance_cfg = p_cb->p_current_transaction->p_required_twi_cfg == NULL ? &p_cb->default_configuration : p_cb->p_current_transaction->p_required_twi_cfg; if (memcmp(p_cb->p_current_configuration, p_instance_cfg, sizeof(*p_instance_cfg)) != 0) { ret_code_t err_code; nrf_drv_twi_uninit(&p_nrf_twi_mngr->twi); err_code = nrf_drv_twi_init(&p_nrf_twi_mngr->twi, p_instance_cfg, twi_event_handler, (void *)p_nrf_twi_mngr); ASSERT(err_code == NRF_SUCCESS); nrf_drv_twi_enable(&p_nrf_twi_mngr->twi); UNUSED_VARIABLE(err_code); p_cb->p_current_configuration = p_instance_cfg; } // Try to start first transfer for this new transaction. p_cb->current_transfer_idx = 0; result = start_transfer(p_nrf_twi_mngr); // If transaction started successfully there is nothing more to do here now. if (result == NRF_SUCCESS) { return; } // Transfer failed to start - notify user that this transaction // cannot be started and try with next one (in next iteration of // the loop). transaction_end_signal(p_nrf_twi_mngr, result); switch_transaction = true; } } } static void twi_event_handler(nrf_drv_twi_evt_t const * p_event, void * p_context) { ASSERT(p_event != NULL); nrf_twi_mngr_t * p_nrf_twi_mngr = (nrf_twi_mngr_t *)p_context; ret_code_t result; // This callback should be called only during transaction. ASSERT(p_nrf_twi_mngr->p_nrf_twi_mngr_cb->p_current_transaction != NULL); if (p_event->type == NRF_DRV_TWI_EVT_DONE) { result = NRF_SUCCESS; // Transfer finished successfully. If there is another one to be // performed in the current transaction, start it now. // [use a local variable to avoid using two volatile variables in one // expression] uint8_t current_transfer_idx = p_nrf_twi_mngr->p_nrf_twi_mngr_cb->current_transfer_idx; ++current_transfer_idx; if (current_transfer_idx < p_nrf_twi_mngr->p_nrf_twi_mngr_cb->p_current_transaction->number_of_transfers) { p_nrf_twi_mngr->p_nrf_twi_mngr_cb->current_transfer_idx = current_transfer_idx; result = start_transfer(p_nrf_twi_mngr); if (result == NRF_SUCCESS) { // The current transaction goes on and we've successfully // started its next transfer -> there is nothing more to do. return; } // [if the next transfer could not be started due to some error // we finish the transaction with this error code as the result] } } else { result = NRF_ERROR_INTERNAL; } // The current transaction has been completed or interrupted by some error. // Notify the user and start next one (if there is any). transaction_end_signal(p_nrf_twi_mngr, result); // [we switch transactions here ('p_nrf_twi_mngr->p_current_transaction' is set // to NULL only if there is nothing more to do) in order to not generate // spurious idle status (even for a moment)] start_pending_transaction(p_nrf_twi_mngr, true); } ret_code_t nrf_twi_mngr_init(nrf_twi_mngr_t const * p_nrf_twi_mngr, nrf_drv_twi_config_t const * p_default_twi_config) { ASSERT(p_nrf_twi_mngr != NULL); ASSERT(p_nrf_twi_mngr->p_queue != NULL); ASSERT(p_nrf_twi_mngr->p_queue->size > 0); ASSERT(p_default_twi_config != NULL); ret_code_t err_code; err_code = nrf_drv_twi_init(&p_nrf_twi_mngr->twi, p_default_twi_config, twi_event_handler, (void *)p_nrf_twi_mngr); VERIFY_SUCCESS(err_code); nrf_drv_twi_enable(&p_nrf_twi_mngr->twi); p_nrf_twi_mngr->p_nrf_twi_mngr_cb->p_current_transaction = NULL; p_nrf_twi_mngr->p_nrf_twi_mngr_cb->default_configuration = *p_default_twi_config; p_nrf_twi_mngr->p_nrf_twi_mngr_cb->p_current_configuration = &p_nrf_twi_mngr->p_nrf_twi_mngr_cb->default_configuration; return NRF_SUCCESS; } void nrf_twi_mngr_uninit(nrf_twi_mngr_t const * p_nrf_twi_mngr) { ASSERT(p_nrf_twi_mngr != NULL); nrf_drv_twi_uninit(&p_nrf_twi_mngr->twi); p_nrf_twi_mngr->p_nrf_twi_mngr_cb->p_current_transaction = NULL; } ret_code_t nrf_twi_mngr_schedule(nrf_twi_mngr_t const * p_nrf_twi_mngr, nrf_twi_mngr_transaction_t const * p_transaction) { ASSERT(p_nrf_twi_mngr != NULL); ASSERT(p_transaction != NULL); ASSERT(p_transaction->p_transfers != NULL); ASSERT(p_transaction->number_of_transfers != 0); ret_code_t result = NRF_SUCCESS; result = nrf_queue_push(p_nrf_twi_mngr->p_queue, (void *)(&p_transaction)); if (result == NRF_SUCCESS) { // New transaction has been successfully added to queue, // so if we are currently idle it's time to start the job. start_pending_transaction(p_nrf_twi_mngr, false); } return result; } static void internal_transaction_cb(ret_code_t result, void * p_user_data) { nrf_twi_mngr_cb_data_t *p_cb_data = (nrf_twi_mngr_cb_data_t *)p_user_data; p_cb_data->transaction_result = result; p_cb_data->transaction_in_progress = false; } ret_code_t nrf_twi_mngr_perform(nrf_twi_mngr_t const * p_nrf_twi_mngr, nrf_drv_twi_config_t const * p_config, nrf_twi_mngr_transfer_t const * p_transfers, uint8_t number_of_transfers, void (* user_function)(void)) { ASSERT(p_nrf_twi_mngr != NULL); ASSERT(p_transfers != NULL); ASSERT(number_of_transfers != 0); nrf_twi_mngr_cb_data_t cb_data = { .transaction_in_progress = true }; nrf_twi_mngr_transaction_t internal_transaction = { .callback = internal_transaction_cb, .p_user_data = (void *)&cb_data, .p_transfers = p_transfers, .number_of_transfers = number_of_transfers, .p_required_twi_cfg = p_config }; ret_code_t result = nrf_twi_mngr_schedule(p_nrf_twi_mngr, &internal_transaction); VERIFY_SUCCESS(result); while (cb_data.transaction_in_progress) { if (user_function) { user_function(); } } return cb_data.transaction_result; } #endif //NRF_MODULE_ENABLED(NRF_TWI_MNGR)