From f12a616e0cdee71440b72f7602825db424d37879 Mon Sep 17 00:00:00 2001 From: Oleksij Rempel Date: Fri, 14 Jul 2017 11:42:46 +0200 Subject: [PATCH] spi: loopback-test: provide loop_req option. Provide a module parameter to request internal loop by the SPI master controller. This should make loop testing easier without extra HW modification. For test automation a logic analyzer is recommended for host controller-independent verification. An example test rig configuration and procedure: i.MX6S RIoRBoard Logic Analyzer ----------------------------------------- (J13 4) GND ------------- GND (J13 6) CSPI3-CLK ------> PIN 3 (J13 8) CSPI3-MOSI <----- PIN 2 ^ - internal loop configured by SPI_LOOP | or can be user external jamper. (J13 10) CSPI3-MISO -----> PIN 1 grab some data and decode it: sigrok-cli -d fx2lafw --time 160000 --config samplerate=10m \ --channels 0-2 -o dump.sr sigrok-cli -i dump.sr -P spi:mosi=1:clk=2 > result_for_regression_tests Signed-off-by: Oleksij Rempel Signed-off-by: Mark Brown --- drivers/spi/spi-loopback-test.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/spi/spi-loopback-test.c b/drivers/spi/spi-loopback-test.c index 3459965004f8..0d3c56e2526c 100644 --- a/drivers/spi/spi-loopback-test.c +++ b/drivers/spi/spi-loopback-test.c @@ -51,6 +51,12 @@ MODULE_PARM_DESC(loopback, "is checked to match tx_buf after the spi_message " \ "is executed"); +int loop_req; +module_param(loop_req, int, 0); +MODULE_PARM_DESC(loop_req, + "if set controller will be asked to enable test loop mode. " \ + "If controller supported it, MISO and MOSI will be connected"); + /* run only a specific test */ int run_only_test = -1; module_param(run_only_test, int, 0); @@ -313,6 +319,16 @@ static int spi_loopback_test_probe(struct spi_device *spi) { int ret; + if (loop_req) { + spi->mode = SPI_LOOP | spi->mode; + ret = spi_setup(spi); + if (ret) { + dev_err(&spi->dev, "SPI setup with SPI_LOOP failed (%d)\n", + ret); + return ret; + } + } + dev_info(&spi->dev, "Executing spi-loopback-tests\n"); ret = spi_test_run_tests(spi, spi_tests); -- 2.45.2