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From: Ben Gamari <bgamari.foss@gmail.com>
To: grant.likely@secretlab.ca, linux-omap@vger.kernel.org
Cc: Ben Gamari <bgamari.foss@gmail.com>
Subject: [PATCH] mcspi: Add support for GPIO chip select lines
Date: Sun, 13 Mar 2011 15:05:19 -0400	[thread overview]
Message-ID: <1300043119-11262-1-git-send-email-bgamari.foss@gmail.com> (raw)
In-Reply-To: <87ipvmx2ok.fsf@gmail.com>

Many applications require more chip select lines than the board or
processor allow. Introduce a mechanism to allow use of GPIO pins as
chip select lines with the McSPI controller. To use this functionality,
one simply provides a table mapping CS line numbers to GPIO numbers in
omap2_mcspi_platform_config.cs_gpios.

Signed-off-by: Ben Gamari <bgamari.foss@gmail.com>
---
 arch/arm/plat-omap/include/plat/mcspi.h |    3 ++-
 drivers/spi/omap2_mcspi.c               |   15 ++++++++++-----
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/arch/arm/plat-omap/include/plat/mcspi.h b/arch/arm/plat-omap/include/plat/mcspi.h
index 1254e49..cac1d84 100644
--- a/arch/arm/plat-omap/include/plat/mcspi.h
+++ b/arch/arm/plat-omap/include/plat/mcspi.h
@@ -2,7 +2,8 @@
 #define _OMAP2_MCSPI_H
 
 struct omap2_mcspi_platform_config {
-	unsigned short	num_cs;
+	unsigned short num_cs;
+	int *cs_gpios;
 };
 
 struct omap2_mcspi_device_config {
diff --git a/drivers/spi/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c
index abb1ffb..59cbed4 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 +236,15 @@ 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);
+	struct omap2_mcspi_platform_config *pconfig = spi->master->dev.platform_data;
+	if (pconfig->cs_gpios) {
+		int gpio = pconfig->cs_gpios[spi->chip_select];
+		gpio_set_value(gpio, 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)
-- 
1.7.0.4


  reply	other threads:[~2011-03-13 19:05 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <c0ffcf4415b8edbf55d653a620b92fbbbcd8fed7>
     [not found] ` <1297635034-24504-1-git-send-email-bgamari.foss@gmail.com>
     [not found]   ` <20110302215026.GA22854@angua.secretlab.ca>
     [not found]     ` <87sjv517yd.fsf@gmail.com>
     [not found]       ` <f7a269db-3bcf-4bac-8c38-b363e5c7bd0b@email.android.com>
2011-03-13 19:04         ` GPIO chip select support in McSPI Ben Gamari
2011-03-13 19:05           ` Ben Gamari [this message]
2011-03-14 19:27             ` [PATCH] mcspi: Add support for GPIO chip select lines Grant Likely
2011-03-15  2:06               ` Ben Gamari
2011-03-15  2:10                 ` Grant Likely
2011-03-14 19:25           ` GPIO chip select support in McSPI Grant Likely
2011-03-15  2:22             ` Ben Gamari
2011-03-15  3:29               ` Grant Likely
2011-08-30 10:14 McSPI questions pertaining to GPIO chip select support Raju Sana
2011-08-30 13:50 ` Ben Gamari
2011-08-30 13:50   ` [PATCH] mcspi: Add support for GPIO chip select lines Ben Gamari
  -- strict thread matches above, loose matches on Subject: below --
2010-01-28  4:33 McSPI questions pertaining to GPIO chip select support jassi brar
2010-12-21 17:56 ` [PATCH] mcspi: Add support for GPIO chip select lines Ben Gamari
2010-12-23 19:59   ` Tony Lindgren
2010-12-23 21:38   ` Grant Likely
2010-12-23 23:09     ` Ben Gamari
2010-12-24  0:37       ` Grant Likely
2010-12-24  2:27         ` Ben Gamari
2010-12-24  3:28           ` Grant Likely
2010-12-24  6:05             ` Ben Gamari
2011-02-12  8:33               ` Grant Likely
2011-02-13 22:07                 ` Ben Gamari

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