This mechanism is in large part stolen from the s3c64xx-spi module. To
use this functionality, one simply must define a set_level function to
set the CS state and a omap2_mcspi_csinfo struct for each chip select in
the board file.
Each spi_board_info.controller_data should then be set
to point to the appropriate csinfo struct. This will cause the driver to
call the csinfo->set_level function instead of toggling the McSPI chip
select lines.
Signed-off-by: Ben Gamari <bgamari.f...@gmail.com>
---
arch/arm/plat-omap/include/plat/mcspi.h | 14 ++++++++++++++
drivers/spi/omap2_mcspi.c | 14 +++++++++-----
2 files changed, 23 insertions(+), 5 deletions(-)
diff --git a/arch/arm/plat-omap/include/plat/mcspi.h
b/arch/arm/plat-omap/include/plat/mcspi.h
index 1254e49..ab84b8d 100644
--- a/arch/arm/plat-omap/include/plat/mcspi.h
+++ b/arch/arm/plat-omap/include/plat/mcspi.h
@@ -1,6 +1,20 @@
#ifndef _OMAP2_MCSPI_H
#define _OMAP2_MCSPI_H
+/**
+ * struct omap2_mcspi_csinfo - Chip Select description
+ * @line: Custom 'identity' of the CS line
+ * @set_level: Function to set the state of a given CS line
+ *
+ * This is to allow use of GPIO lines as CS lines. Allocate and initialize one
+ * in the machine init code and make spi_board_info.controller_data point to
+ * it.
+ */
+struct omap2_mcspi_csinfo {
+ unsigned line;
+ void (*set_level)(unsigned line_id, int lvl);
+};
+
struct omap2_mcspi_platform_config {
unsigned short num_cs;
};
diff --git a/drivers/spi/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c
index 2a651e6..92ccbd6 100644
--- a/drivers/spi/omap2_mcspi.c
+++ b/drivers/spi/omap2_mcspi.c
@@ -35,6 +35,7 @@
#include <linux/slab.h>
#include <linux/spi/spi.h>
+#include <linux/gpio.h>
#include <plat/dma.h>
#include <plat/clock.h>
@@ -235,11 +236,14 @@ static void omap2_mcspi_set_enable(const struct
spi_device *spi, int enable)
static void omap2_mcspi_force_cs(struct spi_device *spi, int cs_active)
{
- u32 l;
-
- l = mcspi_cached_chconf0(spi);
- MOD_REG_BIT(l, OMAP2_MCSPI_CHCONF_FORCE, cs_active);
- mcspi_write_chconf0(spi, l);
+ if (spi->controller_data) {
+ struct omap2_mcspi_csinfo *csinfo = spi->controller_data;
+ (*csinfo->set_level)(csinfo->line, cs_active);
+ } else {
+ u32 l = mcspi_cached_chconf0(spi);
+ MOD_REG_BIT(l, OMAP2_MCSPI_CHCONF_FORCE, cs_active);
+ mcspi_write_chconf0(spi, l);
+ }
}
static void omap2_mcspi_set_master_mode(struct spi_master *master)
--
1.7.1
--
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