1 // Copyright 2021 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 <fcntl.h> 18 #include <linux/spi/spidev.h> 19 #include <linux/types.h> 20 #include <sys/ioctl.h> 21 #include <unistd.h> 22 23 #include "pw_log/log.h" 24 #include "pw_spi/chip_selector.h" 25 #include "pw_spi/device.h" 26 #include "pw_spi/initiator.h" 27 namespace pw::spi { 28 29 // Linux userspace implementation of the SPI Initiator 30 class LinuxInitiator : public Initiator { 31 public: 32 // Configure the Linux Initiator object for use with a bus specified by path, 33 // with a maximum bus-speed (in hz). LinuxInitiator(const char * path,uint32_t max_speed_hz)34 constexpr LinuxInitiator(const char* path, uint32_t max_speed_hz) 35 : path_(path), max_speed_hz_(max_speed_hz), fd_(-1) {} 36 ~LinuxInitiator(); 37 38 // Implements pw::spi::Initiator 39 Status Configure(const Config& config) override; 40 Status WriteRead(ConstByteSpan write_buffer, ByteSpan read_buffer) override; 41 42 private: 43 Status LazyInit(); 44 45 const char* path_; 46 uint32_t max_speed_hz_; 47 int fd_; 48 }; 49 50 // Linux userspace implementation of SPI ChipSelector 51 class LinuxChipSelector : public ChipSelector { 52 public: 53 Status SetActive(bool active) override; 54 }; 55 56 } // namespace pw::spi 57