diff options
Diffstat (limited to 'mpm/lib')
| -rw-r--r-- | mpm/lib/spi/spidev.c | 97 | ||||
| -rw-r--r-- | mpm/lib/spi/spidev_iface.cpp | 22 |
2 files changed, 78 insertions, 41 deletions
diff --git a/mpm/lib/spi/spidev.c b/mpm/lib/spi/spidev.c index 929b61aa9..1339fa1e6 100644 --- a/mpm/lib/spi/spidev.c +++ b/mpm/lib/spi/spidev.c @@ -17,6 +17,8 @@ #include "spidev.h" #include <fcntl.h> +#include <errno.h> +#include <string.h> #include <sys/ioctl.h> #include <linux/types.h> #include <linux/spi/spidev.h> @@ -30,56 +32,91 @@ int init_spi(int *fd, const char *device, ) { int err; + if (!fd) + { + fprintf(stderr, "%s: was passed a null pointer\n", + __func__); + return -EINVAL; + } + *fd = open(device, O_RDWR); if (*fd < 0) { - fprintf(stderr, "%s: Failed to open device\n", __func__); - return err; + fprintf(stderr, "%s: Failed to open device. %s\n", + __func__, strerror(*fd)); + return *fd; } - uint32_t requested_mode = mode; - err = ioctl(*fd, SPI_IOC_WR_MODE32, &mode); - if (err < 0) { - fprintf(stderr, "%s: Failed to set mode\n", __func__); - return err;; + // SPI_IOC_WR commands interpret our pointer as non-const, so play it safe + uint32_t set_mode = mode; + if (ioctl(*fd, SPI_IOC_WR_MODE32, &set_mode) < 0) + { + int err = errno; + fprintf(stderr, "%s: Failed to set mode. %s\n", + __func__, strerror(err)); + return err; } - err = ioctl(*fd, SPI_IOC_RD_MODE32, &mode); - if (err < 0) { - fprintf(stderr, "%s: Failed to get mode\n", __func__); + uint32_t coerced_mode; + if (ioctl(*fd, SPI_IOC_RD_MODE32, &coerced_mode) < 0) + { + int err = errno; + fprintf(stderr, "%s: Failed to get mode. %s\n", + __func__, strerror(err)); return err; } - if (requested_mode != mode) { - return 2; + + if (coerced_mode != mode) { + fprintf(stderr, "%s: Failed to set mode to %d, got %d\n", + __func__, mode, coerced_mode); + return -ENOTSUP; } - uint8_t requested_bits_per_word; - err = ioctl(*fd, SPI_IOC_WR_BITS_PER_WORD, &bits_per_word); - if (err < 0) { - fprintf(stderr, "%s: Failed to set bits per word\n", __func__); + uint8_t set_bits_per_word = bits_per_word; + if (ioctl(*fd, SPI_IOC_WR_BITS_PER_WORD, &set_bits_per_word) < 0) + { + int err = errno; + fprintf(stderr, "%s: Failed to set bits per word. %s\n", + __func__, strerror(err)); return err; } - err = ioctl(*fd, SPI_IOC_RD_BITS_PER_WORD, &bits_per_word); - if (err) { - fprintf(stderr, "%s: Failed to get bits per word\n", __func__); + + uint8_t coerced_bits_per_word; + if (ioctl(*fd, SPI_IOC_RD_BITS_PER_WORD, &coerced_bits_per_word) < 0) + { + int err = errno; + fprintf(stderr, "%s: Failed to get bits per word\n", + __func__, strerror(err)); return err; } - if (requested_bits_per_word != bits_per_word) { - return 2; + + if (coerced_bits_per_word != bits_per_word) { + fprintf(stderr, "%s: Failed to set bits per word to %d, got %d\n", + __func__, bits_per_word, coerced_bits_per_word); + return -ENOTSUP; } - uint32_t requested_speed_hz = speed_hz; - err = ioctl(*fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed_hz); - if (err < 0) { - fprintf(stderr, "%s: Failed to set speed\n", __func__); + uint32_t set_speed_hz = speed_hz; + if (ioctl(*fd, SPI_IOC_WR_MAX_SPEED_HZ, &set_speed_hz) < 0) + { + int err = errno; + fprintf(stderr, "%s: Failed to set speed\n", + __func__, strerror(err)); return err; } - err = ioctl(*fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed_hz); - if (err < 0) { - fprintf(stderr, "%s: Failed to get speed\n", __func__); + + uint32_t coerced_speed_hz; + if (ioctl(*fd, SPI_IOC_RD_MAX_SPEED_HZ, &coerced_speed_hz) < 0) + { + int err = errno; + fprintf(stderr, "%s: Failed to get speed\n", + __func__, strerror(err)); return err; } - if (requested_speed_hz != speed_hz) { - return 2; + + if (coerced_speed_hz != speed_hz) { + fprintf(stderr, "%s: Failed to set speed to %d, got %d\n", + __func__, speed_hz, coerced_speed_hz); + return -ENOTSUP; } return 0; diff --git a/mpm/lib/spi/spidev_iface.cpp b/mpm/lib/spi/spidev_iface.cpp index 522238e19..8be73471d 100644 --- a/mpm/lib/spi/spidev_iface.cpp +++ b/mpm/lib/spi/spidev_iface.cpp @@ -21,6 +21,7 @@ extern "C" { #include "spidev.h" } +#include <fcntl.h> #include <linux/spi/spidev.h> #include <boost/format.hpp> @@ -42,22 +43,21 @@ public: ) : _speed(max_speed_hz), _mode(spi_mode) { - - if (!init_spi( + if (init_spi( &_fd, device.c_str(), - _mode, _speed, _bits, _delay - )) { + _mode, _speed, _bits, _delay) < 0) + { throw mpm::runtime_error(str( - boost::format("Could not initialize spidev device %s") - % device - )); + boost::format("Could not initialize spidev device %s") + % device)); } - if (_fd < 0) { + + if (_fd < 0) + { throw mpm::runtime_error(str( - boost::format("Could not open spidev device %s") - % device - )); + boost::format("Could not open spidev device %s") + % device)); } } |