diff options
Diffstat (limited to 'tools/spi')
| -rw-r--r-- | tools/spi/spidev_test.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/tools/spi/spidev_test.c b/tools/spi/spidev_test.c index 83844f8b862a..b0ca44c70e83 100644 --- a/tools/spi/spidev_test.c +++ b/tools/spi/spidev_test.c @@ -417,6 +417,7 @@ int main(int argc, char *argv[]) { int ret = 0; int fd; + uint32_t request; parse_opts(argc, argv); @@ -430,13 +431,23 @@ int main(int argc, char *argv[]) /* * spi mode */ + /* WR is make a request to assign 'mode' */ + request = mode; ret = ioctl(fd, SPI_IOC_WR_MODE32, &mode); if (ret == -1) pabort("can't set spi mode"); + /* RD is read what mode the device actually is in */ ret = ioctl(fd, SPI_IOC_RD_MODE32, &mode); if (ret == -1) pabort("can't get spi mode"); + /* Drivers can reject some mode bits without returning an error. + * Read the current value to identify what mode it is in, and if it + * differs from the requested mode, warn the user. + */ + if (request != mode) + printf("WARNING device does not support requested mode 0x%x\n", + request); /* * bits per word |