greybus: add framework for 'struct gbuf'

greybus-y := core.o

greybus-y := core.o gbuf.o

obj-m += greybus.o

obj-m += i2c-gb.o

/*

 * Greybus gbuf handling

 *

 * Copyright 2014 Google Inc.

 *

 * Released under the GPLv2 only.

 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/types.h>

#include <linux/module.h>

#include <linux/moduleparam.h>

#include <linux/kernel.h>

#include <linux/device.h>

#include "greybus.h"

struct gbuf *greybus_alloc_gbuf(struct greybus_device *gdev,

				struct cport *cport,

				gfp_t mem_flags)

{

	return NULL;

}

void greybus_free_gbuf(struct gbuf *gbuf)

{

}

int greybus_submit_gbuf(struct gbuf *gbuf, gfp_t mem_flags)

{

	return -ENOMEM;

}

int greybus_kill_gbuf(struct gbuf *gbuf)

{

	return -ENOMEM;

}

	.match_flags	= GREYBUS_DEVICE_ID_MATCH_SERIAL,	\

	.lSerial	= (serial),

struct greybus_descriptor {

	__u16	wVendor;

	__u16	wProduct;

	__u64	lSerialNumber;

};

struct gbuf;

struct cport {

	u16	number;

	// FIXME, what else?

};

typedef void (*gbuf_complete_t)(struct gbuf *gbuf);

struct gbuf {

	struct kref kref;

	void *hcpriv;

	struct list_head anchor_list;

	struct gbuf_anchor *anchor;	// FIXME do we need?

	struct greybus_device *gdev;

	struct cport *cport;

	int status;

	void *transfer_buffer;

	u32 transfer_flags;		/* flags for the transfer buffer */

	u32 transfer_buffer_length;

	u32 actual_length;

	struct scatterlist *sg;		// FIXME do we need?

	int num_sgs;

	void *context;

	gbuf_complete_t complete;

};

/*

 * gbuf->transfer_flags

 */

#define GBUF_FREE_BUFFER	BIT(0)	/* Free the transfer buffer with the gbuf */

struct greybus_device {

	struct device dev;

	struct greybus_descriptor descriptor;

	int num_cport;

	struct cport cport[0];

};

#define to_greybus_device(d) container_of(d, struct greybus_device, dev)

struct gbuf *greybus_alloc_gbuf(struct greybus_device *gdev,

				struct cport *cport,

				gfp_t mem_flags);

void greybus_free_gbuf(struct gbuf *gbuf);

int greybus_submit_gbuf(struct gbuf *gbuf, gfp_t mem_flags);

int greybus_kill_gbuf(struct gbuf *gbuf);

struct greybus_driver {

	const char *name;