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| author | Lorenz Meier <lm@inf.ethz.ch> | 2014-05-15 14:24:24 +0200 |
|---|---|---|
| committer | Lorenz Meier <lm@inf.ethz.ch> | 2015-01-02 16:01:15 +0100 |
| commit | ae3e5d7a7fa62c4e85efaf532e6e21626d20c726 (patch) | |
| tree | 26584a4031c1c271477317369ead896f74d84bc9 /src/drivers | |
| parent | 500ac1443bcfc9082a76b0a2a0a72b0a3d539b9b (diff) | |
| download | px4-firmware-i2c_crc_master.tar.gz px4-firmware-i2c_crc_master.tar.bz2 px4-firmware-i2c_crc_master.zip | |
px4io firmware and px4io driver: Add CRC32 check for paranoid data integrity assurances.i2c_crc_master
Diffstat (limited to 'src/drivers')
| -rwxr-xr-x | src/drivers/px4io/px4io_i2c.cpp | 37 |
1 files changed, 30 insertions, 7 deletions
diff --git a/src/drivers/px4io/px4io_i2c.cpp b/src/drivers/px4io/px4io_i2c.cpp index c57ddf65b..a2a01c16b 100755 --- a/src/drivers/px4io/px4io_i2c.cpp +++ b/src/drivers/px4io/px4io_i2c.cpp @@ -47,6 +47,7 @@ #include <debug.h> #include <errno.h> #include <unistd.h> +#include <crc32.h> #include <arch/board/board.h> #include <board_config.h> @@ -121,8 +122,8 @@ PX4IO_I2C::write(unsigned address, void *data, unsigned count) page, offset }; - - i2c_msg_s msgv[2]; + uint32_t crc = 0; + i2c_msg_s msgv[3]; msgv[0].flags = 0; msgv[0].buffer = addr; @@ -132,7 +133,14 @@ PX4IO_I2C::write(unsigned address, void *data, unsigned count) msgv[1].buffer = (uint8_t *)values; msgv[1].length = 2 * count; - int ret = transfer(msgv, 2); + msgv[2].flags = I2C_M_NORESTART; + msgv[2].buffer = (uint8_t *)&crc; + msgv[2].length = sizeof(crc); + + crc = crc32part(&addr[0], 2, crc); + crc = crc32part((const uint8_t*)data, 2 * count, crc); + + int ret = transfer(msgv, 3); if (ret == OK) ret = count; return ret; @@ -150,7 +158,8 @@ PX4IO_I2C::read(unsigned address, void *data, unsigned count) page, offset }; - i2c_msg_s msgv[2]; + uint32_t crc; + i2c_msg_s msgv[3]; msgv[0].flags = 0; msgv[0].buffer = addr; @@ -160,9 +169,23 @@ PX4IO_I2C::read(unsigned address, void *data, unsigned count) msgv[1].buffer = (uint8_t *)values; msgv[1].length = 2 * count; - int ret = transfer(msgv, 2); - if (ret == OK) - ret = count; + msgv[2].flags = I2C_M_READ | I2C_M_NORESTART; + msgv[2].buffer = (uint8_t *)&crc; + msgv[2].length = sizeof(crc); + + int ret = transfer(msgv, 3); + if (ret == OK) { + uint32_t tcrc = 0; + + tcrc = crc32part(&addr[0], 2, tcrc); + tcrc = crc32part((const uint8_t*)data, 2 * count, tcrc); + + if (tcrc != crc) { + ret = EIO; + } else { + ret = count; + } + } return ret; } |