From: Michael Barkowski <michaelbarkowski@ruggedcom.com>
To: linuxppc-dev@ozlabs.org
Subject: [PATCH] mpc8xxx_spi: Fix polarity inversion in chipselect
Date: Tue, 18 Aug 2009 11:08:24 -0400 [thread overview]
Message-ID: <4A8AC3E8.5070301@ruggedcom.com> (raw)
If we use open firmware, then alow_flags handles active-low
chipselects, which is the same as SPI_CS_HIGH. This patch fixes the
double negative.
Signed-off-by: Michael Barkowski <michaelbarkowski@ruggedcom.com>
---
Anton,
thanks to your device table matching support patch I can use open firmware
to configure two spi devices on 8360E. I use the gpios node, with flags set
to 1, matching OF_GPIO_ACTIVE_LOW. When I do this I notice that the polarity
was already handled in a different way. Did some searching and didn't find
it had been discussed. Here's what I am doing now - feel free to use it or
abuse it :) (based in galak-powerpc/next plus your patches 1 and 2)
drivers/spi/spi_mpc8xxx.c | 10 ++--------
1 files changed, 2 insertions(+), 8 deletions(-)
diff --git a/drivers/spi/spi_mpc8xxx.c b/drivers/spi/spi_mpc8xxx.c
index 0fd0ec4..36bda94 100644
--- a/drivers/spi/spi_mpc8xxx.c
+++ b/drivers/spi/spi_mpc8xxx.c
@@ -159,14 +159,8 @@ static void mpc8xxx_spi_chipselect(struct spi_device *spi, int value)
{
struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
struct fsl_spi_platform_data *pdata = spi->dev.parent->platform_data;
- bool pol = spi->mode & SPI_CS_HIGH;
struct spi_mpc8xxx_cs *cs = spi->controller_state;
- if (value == BITBANG_CS_INACTIVE) {
- if (pdata->cs_control)
- pdata->cs_control(spi, !pol);
- }
-
if (value == BITBANG_CS_ACTIVE) {
u32 regval = mpc8xxx_spi_read_reg(&mpc8xxx_spi->base->mode);
@@ -189,9 +183,9 @@ static void mpc8xxx_spi_chipselect(struct spi_device *spi, int value)
mpc8xxx_spi_write_reg(mode, regval);
local_irq_restore(flags);
}
- if (pdata->cs_control)
- pdata->cs_control(spi, pol);
}
+ if (pdata->cs_control)
+ pdata->cs_control(spi, value);
}
static
--
1.6.3.3
next reply other threads:[~2009-08-18 15:09 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-08-18 15:08 Michael Barkowski [this message]
2009-08-18 15:16 ` [PATCH] mpc8xxx_spi: Fix polarity inversion in chipselect Michael Barkowski
2009-08-18 16:02 ` Michael Barkowski
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