Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753631AbdGNJmw (ORCPT ); Fri, 14 Jul 2017 05:42:52 -0400 Received: from metis.ext.4.pengutronix.de ([92.198.50.35]:39011 "EHLO metis.ext.4.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752602AbdGNJmv (ORCPT ); Fri, 14 Jul 2017 05:42:51 -0400 From: Oleksij Rempel To: kernel@pengutronix.de, Mark Brown , linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org, linux@rempel-privat.de Cc: Oleksij Rempel Subject: [PATCH v3] spi: loopback-test: provide loop_req option. Date: Fri, 14 Jul 2017 11:42:46 +0200 Message-Id: <20170714094246.32003-1-o.rempel@pengutronix.de> X-Mailer: git-send-email 2.11.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::7 X-SA-Exim-Mail-From: ore@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2148 Lines: 70 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 --- v3: - more rewording after feed back provided by Paul Ferster v2: - some spelling fixes - add more background about testing setup - reword error message. 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 f4875f177df0..cfc7222f0a85 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); -- 2.11.0