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 jumper connection or a SN74AHCT125) Suggested-by: Geert Uytterhoeven <[email protected]> Signed-off-by: Martin Sperl <[email protected]> --- drivers/spi/spi-loopback-test.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) Note: this has been tested by faking SPI_LOOP support inside spi-bcm2835 (master->mode_bits |= SPI_LOOP;) and retaining the external link between MOSI and MISO. diff --git a/drivers/spi/spi-loopback-test.c b/drivers/spi/spi-loopback-test.c index 6e76c3e..15207a7 100644 --- a/drivers/spi/spi-loopback-test.c +++ b/drivers/spi/spi-loopback-test.c @@ -289,7 +289,21 @@ static int spi_loopback_test_probe(struct spi_device *spi) { int ret; - dev_info(&spi->dev, "Executing spi-loopback-tests\n"); + /* enable HW-loopback automatically if the master supports it + * and we have the loopback module parameter unset + */ + if ((!loopback) && (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); + loopback = 1; + } + + dev_info(&spi->dev, "Executing spi-loopback-tests%s\n", + loopback ? " with loopback tests enabled" : ""); 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
