Kevin Zeng | 58b43d3 | 2021-04-16 00:36:16 -0700 | [diff] [blame] | 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 | #include "pw_i2c/register_device.h" |
| 16 | |
Wyatt Hepler | 4298fd0 | 2021-03-19 15:08:10 -0700 | [diff] [blame] | 17 | #include "pw_assert/check.h" |
Kevin Zeng | 58b43d3 | 2021-04-16 00:36:16 -0700 | [diff] [blame] | 18 | #include "pw_bytes/byte_builder.h" |
| 19 | |
| 20 | namespace pw { |
| 21 | namespace i2c { |
| 22 | namespace { |
| 23 | |
| 24 | // Puts the register address data into the buffer based on the size of the |
| 25 | // register address. |
| 26 | void PutRegisterAddressInByteBuilder( |
| 27 | ByteBuilder& byte_builder, |
| 28 | const uint32_t register_address, |
| 29 | const std::endian order, |
| 30 | RegisterAddressSize register_address_size) { |
| 31 | // TODO(b/185952662): Simplify the call site by extending the byte builder |
| 32 | // and endian API. |
| 33 | switch (register_address_size) { |
| 34 | case RegisterAddressSize::k1Byte: |
| 35 | byte_builder.PutUint8(static_cast<uint8_t>(register_address)); |
| 36 | break; |
| 37 | |
| 38 | case RegisterAddressSize::k2Bytes: |
| 39 | byte_builder.PutUint16(static_cast<uint16_t>(register_address), order); |
| 40 | break; |
| 41 | |
| 42 | case RegisterAddressSize::k4Bytes: |
| 43 | byte_builder.PutUint32(register_address, order); |
| 44 | break; |
| 45 | |
| 46 | default: |
| 47 | PW_CRASH("Invalid address size being put in byte buffer"); |
| 48 | } |
| 49 | } |
| 50 | |
| 51 | void PutRegisterData16InByteBuilder(ByteBuilder& byte_builder, |
| 52 | ConstByteSpan register_data, |
| 53 | const std::endian order) { |
| 54 | uint32_t data_pointer_index = 0; |
| 55 | |
| 56 | while (data_pointer_index < register_data.size()) { |
| 57 | const uint16_t data = *reinterpret_cast<const uint16_t*>( |
| 58 | register_data.data() + data_pointer_index); |
| 59 | byte_builder.PutUint16(data, order); |
| 60 | data_pointer_index += sizeof(data); |
| 61 | } |
| 62 | } |
| 63 | |
| 64 | Status PutRegisterData32InByteBuilder(ByteBuilder& byte_builder, |
| 65 | ConstByteSpan register_data, |
| 66 | const std::endian order) { |
| 67 | uint32_t data_pointer_index = 0; |
| 68 | |
| 69 | while (data_pointer_index < register_data.size()) { |
| 70 | const uint32_t data = *reinterpret_cast<const uint32_t*>( |
| 71 | register_data.data() + data_pointer_index); |
| 72 | byte_builder.PutUint32(data, order); |
| 73 | data_pointer_index += sizeof(data); |
| 74 | } |
| 75 | |
| 76 | if (data_pointer_index == register_data.size()) { |
| 77 | return pw::OkStatus(); |
| 78 | } else { |
| 79 | // The write data that was given doesn't align with the expected register |
| 80 | // data size. |
| 81 | return Status::InvalidArgument(); |
| 82 | } |
| 83 | } |
| 84 | |
| 85 | } // namespace |
| 86 | |
| 87 | Status RegisterDevice::WriteRegisters( |
| 88 | const uint32_t register_address, |
| 89 | ConstByteSpan register_data, |
| 90 | const size_t register_data_size, |
| 91 | ByteSpan buffer, |
| 92 | chrono::SystemClock::duration for_at_least) { |
| 93 | // Make sure the buffer is big enough to handle the address and data. |
| 94 | if (buffer.size() < |
| 95 | register_data.size() + static_cast<uint32_t>(register_address_size_)) { |
| 96 | return pw::Status::OutOfRange(); |
| 97 | } |
| 98 | |
| 99 | ByteBuilder builder = ByteBuilder(buffer); |
| 100 | PutRegisterAddressInByteBuilder( |
| 101 | builder, register_address, order_, register_address_size_); |
| 102 | |
| 103 | switch (register_data_size) { |
| 104 | case 1: |
| 105 | builder.append(register_data.data(), register_data.size()); |
| 106 | break; |
| 107 | |
| 108 | case 2: |
| 109 | PutRegisterData16InByteBuilder(builder, register_data, order_); |
| 110 | break; |
| 111 | |
| 112 | case 4: |
| 113 | PutRegisterData32InByteBuilder(builder, register_data, order_); |
| 114 | break; |
| 115 | |
| 116 | default: |
| 117 | PW_CRASH("Invalid data size being put in byte buffer"); |
| 118 | } |
| 119 | |
| 120 | if (!builder.ok()) { |
| 121 | return pw::Status::Internal(); |
| 122 | } |
| 123 | |
| 124 | ConstByteSpan write_buffer(builder.data(), builder.size()); |
| 125 | return WriteFor(write_buffer, for_at_least); |
| 126 | } |
| 127 | |
| 128 | Status RegisterDevice::ReadRegisters( |
| 129 | uint32_t register_address, |
| 130 | ByteSpan return_data, |
| 131 | chrono::SystemClock::duration for_at_least) { |
| 132 | ByteBuffer<sizeof(register_address)> byte_buffer; |
| 133 | |
| 134 | PutRegisterAddressInByteBuilder( |
| 135 | byte_buffer, register_address, order_, register_address_size_); |
| 136 | |
| 137 | if (!byte_buffer.ok()) { |
| 138 | return pw::Status::Internal(); |
| 139 | } |
| 140 | |
| 141 | return WriteReadFor(byte_buffer.data(), |
| 142 | byte_buffer.size(), |
| 143 | return_data.data(), |
| 144 | return_data.size(), |
| 145 | for_at_least); |
| 146 | } |
| 147 | |
| 148 | } // namespace i2c |
| 149 | } // namespace pw |