From: shaftarger <sholchen@gmail.com>
To: linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: shaftarger <shol@livemail.tw>
Subject: [PATCH] spi: dw: fix potential variable assignment error
Date: Fri, 7 Dec 2018 11:28:32 +0800 [thread overview]
Message-ID: <20181207032832.3156-1-shol@livemail.tw> (raw)
spi::mode is defined by framework for several SPI capabilities,
such as polarity, phase, bit-endian, wire number. Directly use this
variable for setting controller's polarity and phase causes other
bit in register being set. Since SPI framework has its definition,
fetch required bit in spi::mode and set to register.
---
drivers/spi/spi-dw.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
index b705f2bdb8b9..c1b0ae5698ba 100644
--- a/drivers/spi/spi-dw.c
+++ b/drivers/spi/spi-dw.c
@@ -317,7 +317,8 @@ static int dw_spi_transfer_one(struct spi_controller *master,
/* Default SPI mode is SCPOL = 0, SCPH = 0 */
cr0 = (transfer->bits_per_word - 1)
| (chip->type << SPI_FRF_OFFSET)
- | (spi->mode << SPI_MODE_OFFSET)
+ | ((((spi->mode & SPI_CPOL)?1:0) << SPI_SCOL_OFFSET) |
+ (((spi->mode & SPI_CPHA)?1:0) << SPI_SCPH_OFFSET))
| (chip->tmode << SPI_TMOD_OFFSET);
/*
--
2.12.2.windows.2
next reply other threads:[~2018-12-07 3:28 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-07 3:28 shaftarger [this message]
2018-12-28 8:33 [PATCH] spi: dw: fix potential variable assignment error shaftarger
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