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 #include "pw_spi_mcuxpresso/spi.h"
16
17 #include <cinttypes>
18 #include <mutex>
19
20 #include "pw_assert/check.h"
21 #include "pw_chrono/system_clock.h"
22 #include "pw_log/log.h"
23 #include "pw_status/status.h"
24 #include "pw_status/try.h"
25
26 namespace pw::spi {
27 namespace {
28
29 using namespace ::std::literals::chrono_literals;
30 constexpr auto kMaxWait = pw::chrono::SystemClock::for_at_least(1000ms);
31
ToPwStatus(int32_t status)32 pw::Status ToPwStatus(int32_t status) {
33 switch (status) {
34 // Intentional fall-through
35 case kStatus_Success:
36 case kStatus_SPI_Idle:
37 return pw::OkStatus();
38 case kStatus_ReadOnly:
39 return pw::Status::PermissionDenied();
40 case kStatus_OutOfRange:
41 return pw::Status::OutOfRange();
42 case kStatus_InvalidArgument:
43 return pw::Status::InvalidArgument();
44 case kStatus_Timeout:
45 return pw::Status::DeadlineExceeded();
46 case kStatus_NoTransferInProgress:
47 return pw::Status::FailedPrecondition();
48 // Intentional fall-through
49 case kStatus_Fail:
50 default:
51 PW_LOG_ERROR("Mcuxpresso SPI unknown error code: %d",
52 static_cast<int>(status));
53 return pw::Status::Unknown();
54 }
55 }
56
57 } // namespace
58
~McuxpressoInitiator()59 McuxpressoInitiator::~McuxpressoInitiator() {
60 if (is_initialized()) {
61 SPI_Deinit(register_map_);
62 }
63 }
64
65 // inclusive-language: disable
SpiCallback(SPI_Type *,spi_master_handle_t *,status_t status,void * context)66 void McuxpressoInitiator::SpiCallback(SPI_Type*,
67 spi_master_handle_t*,
68 status_t status,
69 void* context) {
70 auto* driver = static_cast<McuxpressoInitiator*>(context);
71 driver->last_transfer_status_ = ToPwStatus(status);
72 driver->transfer_semaphore_.release();
73 }
74
DoConfigure(const Config & config)75 Status McuxpressoInitiator::DoConfigure(const Config& config) {
76 std::lock_guard lock(mutex_);
77 if (current_config_ && config == *current_config_) {
78 return OkStatus();
79 }
80 return DoConfigureLocked(config, lock);
81 }
82
DoConfigureLocked(const Config & config,const std::lock_guard<sync::Mutex> &)83 Status McuxpressoInitiator::DoConfigureLocked(
84 const Config& config, const std::lock_guard<sync::Mutex>&) {
85 spi_master_config_t master_config = {};
86 SPI_MasterGetDefaultConfig(&master_config);
87
88 if (config.polarity == ClockPolarity::kActiveLow) {
89 master_config.polarity = kSPI_ClockPolarityActiveLow;
90 } else {
91 master_config.polarity = kSPI_ClockPolarityActiveHigh;
92 }
93 if (config.phase == ClockPhase::kRisingEdge) {
94 master_config.phase = kSPI_ClockPhaseFirstEdge;
95 } else {
96 master_config.phase = kSPI_ClockPhaseSecondEdge;
97 }
98
99 if (config.bit_order == BitOrder::kMsbFirst) {
100 master_config.direction = kSPI_MsbFirst;
101 } else {
102 master_config.direction = kSPI_LsbFirst;
103 }
104
105 master_config.enableMaster = true;
106 master_config.baudRate_Bps = baud_rate_bps_;
107
108 master_config.sselNum = static_cast<spi_ssel_t>(pin_);
109 master_config.sselPol = static_cast<spi_spol_t>(kSPI_SpolActiveAllLow);
110
111 // Data width enum value is 1 value below bits_per_word. i.e. 0 = 1;
112 constexpr uint8_t kMinBitsPerWord = 4;
113 constexpr uint8_t kMaxBitsPerWord = 16;
114 PW_CHECK(config.bits_per_word() >= kMinBitsPerWord &&
115 config.bits_per_word() <= kMaxBitsPerWord);
116 master_config.dataWidth =
117 static_cast<_spi_data_width>(config.bits_per_word() - 1);
118
119 SPI_MasterInit(register_map_, &master_config, max_speed_hz_);
120 const auto status = ToPwStatus(SPI_MasterTransferCreateHandle(
121 register_map_, &driver_handle_, McuxpressoInitiator::SpiCallback, this));
122
123 if (status == OkStatus()) {
124 current_config_.emplace(config);
125 }
126 return status;
127 }
128
DoWriteRead(ConstByteSpan write_buffer,ByteSpan read_buffer)129 Status McuxpressoInitiator::DoWriteRead(ConstByteSpan write_buffer,
130 ByteSpan read_buffer) {
131 spi_transfer_t transfer = {};
132
133 transfer.txData =
134 reinterpret_cast<uint8_t*>(const_cast<std::byte*>(write_buffer.data()));
135 transfer.rxData = reinterpret_cast<uint8_t*>(read_buffer.data());
136 if (write_buffer.data() == nullptr && read_buffer.data() != nullptr) {
137 // Read only transaction
138 transfer.dataSize = read_buffer.size();
139 } else if (read_buffer.data() == nullptr && write_buffer.data() != nullptr) {
140 // Write only transaction
141 transfer.dataSize = write_buffer.size();
142 } else {
143 // Take the smallest as the size of transaction
144 transfer.dataSize = write_buffer.size() < read_buffer.size()
145 ? write_buffer.size()
146 : read_buffer.size();
147 }
148 transfer.configFlags = kSPI_FrameAssert;
149
150 std::lock_guard lock(mutex_);
151 if (!current_config_) {
152 PW_LOG_ERROR("Mcuxpresso SPI must be configured before use.");
153 return Status::FailedPrecondition();
154 }
155 if (blocking_) {
156 return ToPwStatus(SPI_MasterTransferBlocking(register_map_, &transfer));
157 }
158
159 PW_TRY(ToPwStatus(SPI_MasterTransferNonBlocking(
160 register_map_, &driver_handle_, &transfer)));
161
162 if (!transfer_semaphore_.try_acquire_for(kMaxWait)) {
163 return Status::DeadlineExceeded();
164 }
165 return last_transfer_status_;
166 }
167 // inclusive-language: enable
168
SetChipSelect(uint32_t pin)169 Status McuxpressoInitiator::SetChipSelect(uint32_t pin) {
170 std::lock_guard lock(mutex_);
171 if (pin == pin_) {
172 return OkStatus();
173 }
174 pin_ = pin;
175 // As configuration has not been called, must be called prior to use, and must
176 // itself set chipselect, set will be delayed until configuration.
177 if (!current_config_) {
178 return OkStatus();
179 }
180 return DoConfigureLocked(*current_config_, lock);
181 }
182
183 } // namespace pw::spi
184