From: "Ivan T. Ivanov" <iivanov@mm-sol.com>
To: Mark Brown <broonie@kernel.org>
Cc: linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-arm-msm@vger.kernel.org
Subject: [PATCH v2] spi: Ensure that CS line is in non-active state after spi_setup()
Date: Fri, 13 Mar 2015 18:43:49 +0200 [thread overview]
Message-ID: <1426265029-12280-1-git-send-email-iivanov@mm-sol.com> (raw)
Some devices samples state of the chip select signal during power up
and act differently based on this state, so SPI core should ensure
that CS line is driven in non-active state after spi_setup().
Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
---
drivers/spi/spi.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index c64a3e5..4023cc9 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1893,6 +1893,8 @@ int spi_setup(struct spi_device *spi)
if (!spi->max_speed_hz)
spi->max_speed_hz = spi->master->max_speed_hz;
+ spi_set_cs(spi, false);
+
if (spi->master->setup)
status = spi->master->setup(spi);
--
1.9.1
next reply other threads:[~2015-03-13 16:44 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-13 16:43 Ivan T. Ivanov [this message]
2015-03-20 16:14 ` [PATCH v2] spi: Ensure that CS line is in non-active state after spi_setup() Ivan T. Ivanov
2015-03-20 16:17 ` Mark Brown
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