greybus: gpio driver
diff --git a/drivers/staging/greybus/Makefile b/drivers/staging/greybus/Makefile
index cc9c3a7..12705b0 100644
--- a/drivers/staging/greybus/Makefile
+++ b/drivers/staging/greybus/Makefile
@@ -3,6 +3,7 @@
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 0000000..98b599b
--- /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>");