1 // Copyright 2023 The Pigweed Authors 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not 4 // use this file except in compliance with the License. You may obtain a copy of 5 // the License at 6 // 7 // https://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 12 // License for the specific language governing permissions and limitations under 13 // the License. 14 15 #pragma once 16 17 #include "fsl_flexio_spi.h" 18 #include "pw_digital_io/digital_io.h" 19 #include "pw_spi/chip_selector.h" 20 #include "pw_spi/initiator.h" 21 #include "pw_status/status.h" 22 #include "pw_sync/binary_semaphore.h" 23 #include "pw_sync/lock_annotations.h" 24 #include "pw_sync/mutex.h" 25 26 namespace pw::spi { 27 28 // Mcuxpresso SDK implementation of the FLEXIO SPI Initiator 29 class McuxpressoFlexIoInitiator : public Initiator { 30 public: 31 McuxpressoFlexIoInitiator(FLEXIO_SPI_Type flexio_spi_config, 32 uint32_t src_clock_hz, 33 uint32_t baud_rate_bps, 34 bool blocking = true) flexio_spi_config_(flexio_spi_config)35 : flexio_spi_config_(flexio_spi_config), 36 src_clock_hz_(src_clock_hz), 37 baud_rate_bps_(baud_rate_bps), 38 blocking_(blocking) {} 39 ~McuxpressoFlexIoInitiator(); 40 41 private: 42 // inclusive-language: disable 43 static void SpiCallback(FLEXIO_SPI_Type*, 44 flexio_spi_master_handle_t*, 45 status_t status, 46 void* context); 47 // Add support to FLEXIO_SPI for negative clock polarity. 48 void ConfigureClock(flexio_spi_master_config_t* masterConfig, 49 ClockPolarity clockPolarity); 50 is_initialized()51 bool is_initialized() { return !!current_config_; } 52 53 // Implements pw::spi::Initiator 54 pw::Status DoConfigure(const Config& config) 55 PW_LOCKS_EXCLUDED(mutex_) override; 56 pw::Status DoWriteRead(ConstByteSpan write_buffer, ByteSpan read_buffer) 57 PW_LOCKS_EXCLUDED(mutex_) override; 58 59 std::optional<const Config> current_config_; 60 FLEXIO_SPI_Type flexio_spi_config_; 61 flexio_spi_master_handle_t driver_handle_; 62 // inclusive-language: enable 63 sync::BinarySemaphore transfer_semaphore_; 64 sync::Mutex mutex_; 65 Status last_transfer_status_; 66 uint32_t src_clock_hz_; 67 uint32_t baud_rate_bps_; 68 bool blocking_; 69 uint8_t transfer_flags_; 70 }; 71 72 // Mcuxpresso userspace implementation of SPI ChipSelector. Implemented using 73 // GPIO so as to support manual control of chip select. GPIO pin passed in 74 // should be already initialized and ungated. 75 class McuxpressoFlexIoChipSelector : public ChipSelector { 76 public: McuxpressoFlexIoChipSelector(digital_io::DigitalOut & pin)77 explicit McuxpressoFlexIoChipSelector(digital_io::DigitalOut& pin) 78 : pin_(pin) {} 79 80 // Implements pw::spi::ChipSelector 81 pw::Status SetActive(bool active) override; 82 83 private: 84 digital_io::DigitalOut& pin_; 85 }; 86 87 } // namespace pw::spi 88