From: Martin Sperl <[email protected]> If the module parameter "loopback" for testing RX to match TX is not set and the spi_master supports SPI_LOOP then SPI_LOOP as well as RX-data testing will get enabled.
When the "loopback" module parameter is set then the SPI_LOOP support in spi_master will not get enabled, which means that MOSI needs to get connected to MISO by some other means (possibly via a simple jumper connection or a SN74AHCT125 connecting MOSI/MISO) Suggested-by: Geert Uytterhoeven <[email protected]> Signed-off-by: Martin Sperl <[email protected]> --- drivers/spi/spi-loopback-test.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) diff --git a/drivers/spi/spi-loopback-test.c b/drivers/spi/spi-loopback-test.c index 001f463..b49065a 100644 --- a/drivers/spi/spi-loopback-test.c +++ b/drivers/spi/spi-loopback-test.c @@ -288,8 +288,34 @@ static struct spi_test spi_tests[] = { static int spi_loopback_test_probe(struct spi_device *spi) { int ret; + char *msg; - dev_info(&spi->dev, "Executing spi-loopback-tests\n"); + /* + * Enable HW-loopback automatically if the master supports it + * and we have the have_rx_buf unset (set means that we have + * got an external loopback enabled, so no need to use SPI_LOOP) + */ + if (!check_rx_buf && (spi->master->mode_bits & SPI_LOOP)) { + spi->mode |= SPI_LOOP; + ret = spi_setup(spi); + if (ret) { + dev_err(&spi->dev, + "spi_setup failed to enable loopback: %i\n", + ret); + return ret; + } + + /* force checking rx_buf for valid (loopback) data */ + check_rx_buf = 1; + + msg = "with SPI_LOOP support"; + } else { + msg = (check_rx_buf) ? + "with external loopback" : + "without any loopback - rx_buf content is not checked"; + } + + dev_info(&spi->dev, "Executing spi-loopback-tests %s\n", msg); ret = spi_test_run_tests(spi, spi_tests); -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
