gpio: Move GE GPIO driver to reside within GPIO subsystem

The GE GPIO driver provides basic support (set direction, read/write state)
for the GPIO provided on some GE single board computers. This patch moves
the driver from the 86xx specific platform directrory to the GPIO subsystem
so that it can be used on non-86xx boards.

Signed-off-by: Martyn Welch <martyn.welch@ge.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

3 files changed, 183 insertions, 0 deletions

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index d0c41188d4e5..0409cf35adda 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -190,6 +190,17 @@ config GPIO_VX855
 	  additional drivers must be enabled in order to use the
 	  functionality of the device.
 
+config GPIO_GE_FPGA
+	bool "GE FPGA based GPIO"
+	depends on GE_FPGA
+	help
+	  Support for common GPIO functionality provided on some GE Single Board
+	  Computers.
+
+	  This driver provides basic support (configure as input or output, read
+	  and write pin state) for GPIO implemented in a number of GE single
+	  board computers.
+
 comment "I2C GPIO expanders:"
 
 config GPIO_MAX7300
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index fa10df604c01..9a8fb54ae462 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_GPIO_CS5535)	+= gpio-cs5535.o
 obj-$(CONFIG_GPIO_DA9052)	+= gpio-da9052.o
 obj-$(CONFIG_ARCH_DAVINCI)	+= gpio-davinci.o
 obj-$(CONFIG_GPIO_EP93XX)	+= gpio-ep93xx.o
+obj-$(CONFIG_GPIO_GE_FPGA)	+= gpio-ge.o
 obj-$(CONFIG_GPIO_IT8761E)	+= gpio-it8761e.o
 obj-$(CONFIG_GPIO_JANZ_TTL)	+= gpio-janz-ttl.o
 obj-$(CONFIG_ARCH_KS8695)	+= gpio-ks8695.o
diff --git a/drivers/gpio/gpio-ge.c b/drivers/gpio/gpio-ge.c
new file mode 100644
index 000000000000..f8e628952921
--- /dev/null
+++ b/drivers/gpio/gpio-ge.c
@@ -0,0 +1,171 @@
+/*
+ * Driver for GE FPGA based GPIO
+ *
+ * Author: Martyn Welch <martyn.welch@ge.com>
+ *
+ * 2008 (c) GE Intelligent Platforms Embedded Systems, Inc.
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2.  This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+/* TODO
+ *
+ * Configuration of output modes (totem-pole/open-drain)
+ * Interrupt configuration - interrupts are always generated the FPGA relies on
+ * the I/O interrupt controllers mask to stop them propergating
+ */
+
+#include <linux/kernel.h>
+#include <linux/compiler.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/of_gpio.h>
+#include <linux/gpio.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+#define GEF_GPIO_DIRECT		0x00
+#define GEF_GPIO_IN		0x04
+#define GEF_GPIO_OUT		0x08
+#define GEF_GPIO_TRIG		0x0C
+#define GEF_GPIO_POLAR_A	0x10
+#define GEF_GPIO_POLAR_B	0x14
+#define GEF_GPIO_INT_STAT	0x18
+#define GEF_GPIO_OVERRUN	0x1C
+#define GEF_GPIO_MODE		0x20
+
+static void _gef_gpio_set(void __iomem *reg, unsigned int offset, int value)
+{
+	unsigned int data;
+
+	data = ioread32be(reg);
+	/* value: 0=low; 1=high */
+	if (value & 0x1)
+		data = data | (0x1 << offset);
+	else
+		data = data & ~(0x1 << offset);
+
+	iowrite32be(data, reg);
+}
+
+
+static int gef_gpio_dir_in(struct gpio_chip *chip, unsigned offset)
+{
+	unsigned int data;
+	struct of_mm_gpio_chip *mmchip = to_of_mm_gpio_chip(chip);
+
+	data = ioread32be(mmchip->regs + GEF_GPIO_DIRECT);
+	data = data | (0x1 << offset);
+	iowrite32be(data, mmchip->regs + GEF_GPIO_DIRECT);
+
+	return 0;
+}
+
+static int gef_gpio_dir_out(struct gpio_chip *chip, unsigned offset, int value)
+{
+	unsigned int data;
+	struct of_mm_gpio_chip *mmchip = to_of_mm_gpio_chip(chip);
+
+	/* Set direction before switching to input */
+	_gef_gpio_set(mmchip->regs + GEF_GPIO_OUT, offset, value);
+
+	data = ioread32be(mmchip->regs + GEF_GPIO_DIRECT);
+	data = data & ~(0x1 << offset);
+	iowrite32be(data, mmchip->regs + GEF_GPIO_DIRECT);
+
+	return 0;
+}
+
+static int gef_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	unsigned int data;
+	int state = 0;
+	struct of_mm_gpio_chip *mmchip = to_of_mm_gpio_chip(chip);
+
+	data = ioread32be(mmchip->regs + GEF_GPIO_IN);
+	state = (int)((data >> offset) & 0x1);
+
+	return state;
+}
+
+static void gef_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+	struct of_mm_gpio_chip *mmchip = to_of_mm_gpio_chip(chip);
+
+	_gef_gpio_set(mmchip->regs + GEF_GPIO_OUT, offset, value);
+}
+
+static int __init gef_gpio_init(void)
+{
+	struct device_node *np;
+	int retval;
+	struct of_mm_gpio_chip *gef_gpio_chip;
+
+	for_each_compatible_node(np, NULL, "gef,sbc610-gpio") {
+
+		pr_debug("%s: Initialising GEF GPIO\n", np->full_name);
+
+		/* Allocate chip structure */
+		gef_gpio_chip = kzalloc(sizeof(*gef_gpio_chip), GFP_KERNEL);
+		if (!gef_gpio_chip) {
+			pr_err("%s: Unable to allocate structure\n",
+				np->full_name);
+			continue;
+		}
+
+		/* Setup pointers to chip functions */
+		gef_gpio_chip->gc.of_gpio_n_cells = 2;
+		gef_gpio_chip->gc.ngpio = 19;
+		gef_gpio_chip->gc.direction_input = gef_gpio_dir_in;
+		gef_gpio_chip->gc.direction_output = gef_gpio_dir_out;
+		gef_gpio_chip->gc.get = gef_gpio_get;
+		gef_gpio_chip->gc.set = gef_gpio_set;
+
+		/* This function adds a memory mapped GPIO chip */
+		retval = of_mm_gpiochip_add(np, gef_gpio_chip);
+		if (retval) {
+			kfree(gef_gpio_chip);
+			pr_err("%s: Unable to add GPIO\n", np->full_name);
+		}
+	}
+
+	for_each_compatible_node(np, NULL, "gef,sbc310-gpio") {
+
+		pr_debug("%s: Initialising GEF GPIO\n", np->full_name);
+
+		/* Allocate chip structure */
+		gef_gpio_chip = kzalloc(sizeof(*gef_gpio_chip), GFP_KERNEL);
+		if (!gef_gpio_chip) {
+			pr_err("%s: Unable to allocate structure\n",
+				np->full_name);
+			continue;
+		}
+
+		/* Setup pointers to chip functions */
+		gef_gpio_chip->gc.of_gpio_n_cells = 2;
+		gef_gpio_chip->gc.ngpio = 6;
+		gef_gpio_chip->gc.direction_input = gef_gpio_dir_in;
+		gef_gpio_chip->gc.direction_output = gef_gpio_dir_out;
+		gef_gpio_chip->gc.get = gef_gpio_get;
+		gef_gpio_chip->gc.set = gef_gpio_set;
+
+		/* This function adds a memory mapped GPIO chip */
+		retval = of_mm_gpiochip_add(np, gef_gpio_chip);
+		if (retval) {
+			kfree(gef_gpio_chip);
+			pr_err("%s: Unable to add GPIO\n", np->full_name);
+		}
+	}
+
+	return 0;
+};
+arch_initcall(gef_gpio_init);
+
+MODULE_DESCRIPTION("GE I/O FPGA GPIO driver");
+MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com");
+MODULE_LICENSE("GPL");