[PATCH v1 1/2] spi: loopback-test: implement testing with no CS

From: Oleksij Rempel
Date: Tue Jul 25 2017 - 03:57:31 EST


To run spi-loopback-tests on HW without modifications, we need to
disable Chip Select. This should avoid surprising side effects for
SPI devices by testing patterns.

Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
---
drivers/spi/spi-loopback-test.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi-loopback-test.c b/drivers/spi/spi-loopback-test.c
index 64a1e6f212c1..bed7403bb6b3 100644
--- a/drivers/spi/spi-loopback-test.c
+++ b/drivers/spi/spi-loopback-test.c
@@ -57,6 +57,11 @@ 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");

+static int no_cs;
+module_param(no_cs, int, 0);
+MODULE_PARM_DESC(no_cs,
+ "if set Chip Select (CS) will not be used");
+
/* run only a specific test */
static int run_only_test = -1;
module_param(run_only_test, int, 0);
@@ -319,11 +324,12 @@ static int spi_loopback_test_probe(struct spi_device *spi)
{
int ret;

- if (loop_req) {
- spi->mode = SPI_LOOP | spi->mode;
+ if (loop_req || no_cs) {
+ spi->mode |= loop_req ? SPI_LOOP : 0;
+ spi->mode |= no_cs ? SPI_NO_CS : 0;
ret = spi_setup(spi);
if (ret) {
- dev_err(&spi->dev, "SPI setup with SPI_LOOP failed (%d)\n",
+ dev_err(&spi->dev, "SPI setup with SPI_LOOP or SPI_NO_CS failed (%d)\n",
ret);
return ret;
}
--
2.11.0