From c16854c3bf562a1f7d1dea92309f35fe97e26889 Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Tue, 12 Aug 2014 12:00:16 +0800
Subject: [PATCH] greybus: gpio driver

---
 drivers/staging/greybus/Makefile  |   1 +
 drivers/staging/greybus/gpio-gb.c | 108 ++++++++++++++++++++++++++++++
 2 files changed, 109 insertions(+)
 create mode 100644 drivers/staging/greybus/gpio-gb.c

diff --git a/drivers/staging/greybus/Makefile b/drivers/staging/greybus/Makefile
index cc9c3a7d17b8..12705b0543a3 100644
--- a/drivers/staging/greybus/Makefile
+++ b/drivers/staging/greybus/Makefile
@@ -3,6 +3,7 @@ greybus-y := core.o gbuf.o
 obj-m += greybus.o
 obj-m += i2c-gb.o
 obj-m += sdio-gb.o
+obj-m += gpio-gb.o
 
 KERNELVER		?= $(shell uname -r)
 KERNELDIR 		?= /lib/modules/$(KERNELVER)/build
diff --git a/drivers/staging/greybus/gpio-gb.c b/drivers/staging/greybus/gpio-gb.c
new file mode 100644
index 000000000000..98b599b462c5
--- /dev/null
+++ b/drivers/staging/greybus/gpio-gb.c
@@ -0,0 +1,108 @@
+/*
+ * GPIO Greybus driver.
+ *
+ * Copyright 2014 Google Inc.
+ *
+ * Released under the GPLv2 only.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/gpio.h>
+#include "greybus.h"
+
+struct gb_gpio {
+	struct gpio_chip chip;
+	struct greybus_device *gdev;
+	// FIXME - some lock?
+};
+
+static const struct greybus_device_id id_table[] = {
+	{ GREYBUS_DEVICE(0x44, 0x44) },	/* make shit up */
+	{ },	/* terminating NULL entry */
+};
+
+static int direction_input(struct gpio_chip *gpio, unsigned nr)
+{
+	struct gp_gpio *gp_gpio = container_of(gpio, struct gp_gpio, chip);
+
+	// FIXME - do something there
+	return 0;
+}
+
+static int direction_output(struct gpio_chip *gpio, unsigned nr, int val)
+{
+	// FIXME - do something there
+	return 0;
+}
+
+static int gpio_get(struct gpio_chip *gpio, unsigned nr)
+{
+	// FIXME - do something there
+	return 0;
+}
+
+static int gpio_set(struct gpio_chip *gpio, unsigned nr, int val)
+{
+	// FIXME - do something there
+	return 0;
+}
+
+static int gpio_gb_probe(struct greybus_device *gdev, const struct greybus_device_id *id)
+{
+	struct gp_gpio *gp_gpio;
+	struct gpio_chip *gpio;
+	struct device *dev = &gdev->dev;
+
+	gp_gpio = devm_kzalloc(dev, sizeof(*gp_gpio), GFP_KERNEL);
+	if (!gp_gpio)
+		return -ENOMEM;
+	gp_gpio->gdev = gdev;
+
+	gpio = &gp_gpio->gpio;
+
+	gpio->label = "greybus_gpio";
+	gpio->owner = THIS_MODULE;
+	gpio->direction_input = direction_input;
+	gpio->direction_output = direction_output;
+	gpio->get = gpio_get;
+	gpio->set = gpio_set;
+	gpio->dbg_show = NULL;
+	gpio->base = 0;			// FIXME!!!
+	gpio->ngpio = 42;		// FIXME!!!
+	gpio->can_sleep = false;	// FIXME!!!
+
+	greybus_set_drvdata(gdev, gp_gpio);
+
+	retval = gpio_chip_add(gpio);
+	if (retval) {
+		dev_err(dev, "Failed to register GPIO\n");
+		return retval;
+	}
+
+	return 0;
+}
+
+static void gpio_gb_disconnect(struct greybus_device *gdev)
+{
+	struct mmc_host *mmc;
+	struct sd_gb_host *host;
+
+	host = greybus_get_drvdata(gdev);
+	mmc = host->mmc;
+
+	mmc_remove_host(mmc);
+	mmc_free_host(mmc);
+}
+
+static struct greybus_driver gpio_gb_driver = {
+	.probe =	gpio_gb_probe,
+	.disconnect =	gpio_gb_disconnect,
+	.id_table =	id_table,
+};
+
+module_greybus_driver(gpio_gb_driver);
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Greybus GPIO driver");
+MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org>");
-- 
2.39.2