sh: mach-sdk7786: Add support for fpga gpios.

The sdk7786 FPGA supports a number of user settable input switches that
are otherwise unused. This wires up a dummy gpio chip for the switch bank
to simply expose them to userspace.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

2 files changed, 51 insertions, 0 deletions

diff --git a/arch/sh/boards/mach-sdk7786/Makefile b/arch/sh/boards/mach-sdk7786/Makefile
index a29f19e85b63..d0f801bd8416 100644
--- a/arch/sh/boards/mach-sdk7786/Makefile
+++ b/arch/sh/boards/mach-sdk7786/Makefile
@@ -1 +1,3 @@
 obj-y   := setup.o fpga.o irq.o
+
+obj-$(CONFIG_GENERIC_GPIO)      += gpio.o
diff --git a/arch/sh/boards/mach-sdk7786/gpio.c b/arch/sh/boards/mach-sdk7786/gpio.c
new file mode 100644
index 000000000000..f71ce09d4e15
--- /dev/null
+++ b/arch/sh/boards/mach-sdk7786/gpio.c
@@ -0,0 +1,49 @@
+/*
+ * SDK7786 FPGA USRGPIR Support.
+ *
+ * Copyright (C) 2010  Paul Mundt
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/gpio.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/io.h>
+#include <mach/fpga.h>
+
+#define NR_FPGA_GPIOS   8
+
+static const char *usrgpir_gpio_names[NR_FPGA_GPIOS] = {
+        "in0", "in1", "in2", "in3", "in4", "in5", "in6", "in7",
+};
+
+static int usrgpir_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
+{
+        /* always in */
+        return 0;
+}
+
+static int usrgpir_gpio_get(struct gpio_chip *chip, unsigned gpio)
+{
+        return !!(fpga_read_reg(USRGPIR) & (1 << gpio));
+}
+
+static struct gpio_chip usrgpir_gpio_chip = {
+        .label                  = "sdk7786-fpga",
+        .names                  = usrgpir_gpio_names,
+        .direction_input        = usrgpir_gpio_direction_input,
+        .get                    = usrgpir_gpio_get,
+        .base                   = -1, /* don't care */
+        .ngpio                  = NR_FPGA_GPIOS,
+};
+
+static int __init usrgpir_gpio_setup(void)
+{
+        return gpiochip_add(&usrgpir_gpio_chip);
+}
+device_initcall(usrgpir_gpio_setup);