[PATCH] spi: omap2-mcspi: Add support for GPIO chipselects
From: Michael Welling
Date: Wed Apr 08 2015 - 17:36:30 EST
This patch allows for GPIOs specified in the devicetree to be used as SPI chipselects
on TI OMAP2 SoCs.
Tested on the AM3354.
Signed-off-by: Michael Welling <mwelling@xxxxxxxx>
---
drivers/spi/spi-omap2-mcspi.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c
index 4df8942..464dec9 100644
--- a/drivers/spi/spi-omap2-mcspi.c
+++ b/drivers/spi/spi-omap2-mcspi.c
@@ -35,6 +35,7 @@
#include <linux/gcd.h>
#include <linux/spi/spi.h>
+#include <linux/gpio.h>
#include <linux/platform_data/spi-omap2-mcspi.h>
@@ -246,6 +247,9 @@ static void omap2_mcspi_force_cs(struct spi_device *spi, int cs_active)
{
u32 l;
+ if (gpio_is_valid(spi->cs_gpio))
+ gpio_set_value(spi->cs_gpio, (cs_active) ? 0 : 1);
+
l = mcspi_cached_chconf0(spi);
if (cs_active)
l |= OMAP2_MCSPI_CHCONF_FORCE;
@@ -1015,6 +1019,12 @@ static int omap2_mcspi_setup(struct spi_device *spi)
if (ret < 0)
return ret;
+ if (gpio_is_valid(spi->cs_gpio)) {
+ if (gpio_request(spi->cs_gpio, dev_name(&spi->dev)) == 0)
+ gpio_direction_output(spi->cs_gpio,
+ !(spi->mode & SPI_CS_HIGH));
+ }
+
ret = omap2_mcspi_setup_transfer(spi, NULL);
pm_runtime_mark_last_busy(mcspi->dev);
pm_runtime_put_autosuspend(mcspi->dev);
--
1.7.9.5
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