1 /* 2 * Copyright (C) 2015 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include <stdio.h> 18 #include <stdint.h> 19 #include <sys/ioctl.h> 20 #include <linux/spi/spidev.h> 21 22 #include "spi.h" 23 24 uint8_t spi_write_data(handle_t *handle, uint8_t *buffer, int length) 25 { 26 spi_handle_t *spi_handle = (spi_handle_t *)handle; 27 struct spi_ioc_transfer xfer = 28 { 29 .len = length + 1, 30 .tx_buf = (unsigned long)buffer, 31 .rx_buf = (unsigned long)buffer, 32 .cs_change = 1, 33 }; 34 35 buffer[length] = checksum(handle, buffer, length); 36 37 if (ioctl(spi_handle->fd, SPI_IOC_MESSAGE(1), &xfer) >= 0) 38 return buffer[length]; 39 else 40 return CMD_NACK; 41 } 42 43 uint8_t spi_write_cmd(handle_t *handle, uint8_t cmd) 44 { 45 spi_handle_t *spi_handle = (spi_handle_t *)handle; 46 uint8_t buffer[] = 47 { 48 CMD_SOF, 49 cmd, 50 ~cmd 51 }; 52 struct spi_ioc_transfer xfer = 53 { 54 .len = sizeof(buffer), 55 .tx_buf = (unsigned long)buffer, 56 .rx_buf = (unsigned long)buffer, 57 .cs_change = 1, 58 }; 59 60 if (ioctl(spi_handle->fd, SPI_IOC_MESSAGE(1), &xfer) >= 0) 61 return CMD_ACK; 62 else 63 return CMD_NACK; 64 } 65 66 uint8_t spi_read_data(handle_t *handle, uint8_t *data, int length) 67 { 68 spi_handle_t *spi_handle = (spi_handle_t *)handle; 69 uint8_t buffer[] = 70 { 71 0x00 72 }; 73 struct spi_ioc_transfer xfer[] = 74 { 75 { 76 .len = sizeof(buffer), 77 .tx_buf = (unsigned long)buffer, 78 .rx_buf = (unsigned long)buffer, 79 }, 80 { 81 .len = length, 82 .tx_buf = (unsigned long)data, 83 .rx_buf = (unsigned long)data, 84 .cs_change = 1, 85 } 86 }; 87 88 if (ioctl(spi_handle->fd, SPI_IOC_MESSAGE(2), xfer) >= 0) 89 return CMD_ACK; 90 else 91 return CMD_NACK; 92 } 93 94 uint8_t spi_read_ack(handle_t *handle) 95 { 96 spi_handle_t *spi_handle = (spi_handle_t *)handle; 97 uint16_t timeout = 65535; 98 uint8_t ret; 99 uint8_t buffer[] = 100 { 101 0x00, 102 }; 103 struct spi_ioc_transfer xfer = 104 { 105 .len = sizeof(buffer), 106 .tx_buf = (unsigned long)buffer, 107 .rx_buf = (unsigned long)buffer, 108 .cs_change = 1, 109 }; 110 111 if (ioctl(spi_handle->fd, SPI_IOC_MESSAGE(1), &xfer) >= 0) { 112 do { 113 ioctl(spi_handle->fd, SPI_IOC_MESSAGE(1), &xfer); 114 timeout --; 115 } while (buffer[0] != CMD_ACK && buffer[0] != CMD_NACK && timeout > 0); 116 117 if (buffer[0] != CMD_ACK && buffer[0] != CMD_NACK && timeout == 0) 118 ret = CMD_NACK; 119 else 120 ret = buffer[0]; 121 ioctl(spi_handle->fd, SPI_IOC_MESSAGE(1), &xfer); 122 123 return ret; 124 } else { 125 return CMD_NACK; 126 } 127 } 128 129 uint8_t spi_sync(handle_t *handle) 130 { 131 spi_handle_t *spi_handle = (spi_handle_t *)handle; 132 uint8_t buffer[] = 133 { 134 CMD_SOF, 135 }; 136 struct spi_ioc_transfer xfer = 137 { 138 .len = sizeof(buffer), 139 .tx_buf = (unsigned long)buffer, 140 .rx_buf = (unsigned long)buffer, 141 .cs_change = 1, 142 }; 143 144 if (ioctl(spi_handle->fd, SPI_IOC_MESSAGE(1), &xfer) >= 0) 145 return handle->read_ack(handle); 146 else 147 return CMD_NACK; 148 } 149 150 int spi_init(handle_t *handle) 151 { 152 spi_handle_t *spi_handle = (spi_handle_t *)handle; 153 uint8_t tmp8; 154 uint32_t tmp32; 155 156 handle->cmd_erase = CMD_ERASE; 157 handle->cmd_read_memory = CMD_READ_MEMORY; 158 handle->cmd_write_memory = CMD_WRITE_MEMORY; 159 160 handle->write_data = spi_write_data; 161 handle->write_cmd = spi_write_cmd; 162 handle->read_data = spi_read_data; 163 handle->read_ack = spi_read_ack; 164 165 tmp8 = SPI_MODE_0; 166 if (ioctl(spi_handle->fd, SPI_IOC_WR_MODE, &tmp8) < 0) { 167 perror("Error setting mode"); 168 return -1; 169 } 170 171 tmp32 = 8000000; 172 if (ioctl(spi_handle->fd, SPI_IOC_WR_MAX_SPEED_HZ, &tmp32) < 0) { 173 perror("Error setting speed"); 174 return -1; 175 } 176 177 tmp8 = 8; 178 if (ioctl(spi_handle->fd, SPI_IOC_WR_BITS_PER_WORD, &tmp8) < 0) { 179 perror("Error setting bits per word"); 180 return -1; 181 } 182 183 if (spi_sync(handle) == CMD_ACK) 184 return 0; 185 else 186 return -1; 187 } 188
