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/*
* USB host driver for the Greybus "generic" USB module.
*
* Copyright 2014 Google Inc.
* Copyright 2014 Linaro Ltd.
*
* Released under the GPLv2 only.
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/usb.h>
#include <linux/usb/hcd.h>
#include "greybus.h"
/* Version of the Greybus USB protocol we support */
#define GB_USB_VERSION_MAJOR 0x00
#define GB_USB_VERSION_MINOR 0x01
/* Greybus USB request types */
#define GB_USB_TYPE_INVALID 0x00
#define GB_USB_TYPE_PROTOCOL_VERSION 0x01
#define GB_USB_TYPE_HCD_START 0x02
#define GB_USB_TYPE_HCD_STOP 0x03
#define GB_USB_TYPE_HUB_CONTROL 0x04
struct gb_usb_hub_control_request {
__le16 typeReq;
__le16 wValue;
__le16 wIndex;
__le16 wLength;
};
struct gb_usb_hub_control_response {
u8 buf[0];
};
struct gb_usb_device {
struct gb_connection *connection;
u8 version_major;
u8 version_minor;
};
static inline struct gb_usb_device *to_gb_usb_device(struct usb_hcd *hcd)
{
return (struct gb_usb_device *)hcd->hcd_priv;
}
static inline struct usb_hcd *gb_usb_device_to_hcd(struct gb_usb_device *dev)
{
return container_of((void *)dev, struct usb_hcd, hcd_priv);
}
/* Define get_version() routine */
define_get_version(gb_usb_device, USB);
static void hcd_stop(struct usb_hcd *hcd)
{
struct gb_usb_device *dev = to_gb_usb_device(hcd);
int ret;
ret = gb_operation_sync(dev->connection, GB_USB_TYPE_HCD_STOP,
NULL, 0, NULL, 0);
if (ret)
dev_err(&dev->connection->dev, "HCD stop failed '%d'\n", ret);
}
static int hcd_start(struct usb_hcd *hcd)
{
struct usb_bus *bus = hcd_to_bus(hcd);
struct gb_usb_device *dev = to_gb_usb_device(hcd);
int ret;
ret = gb_operation_sync(dev->connection, GB_USB_TYPE_HCD_START,
NULL, 0, NULL, 0);
if (ret) {
dev_err(&dev->connection->dev, "HCD start failed '%d'\n", ret);
return ret;
}
hcd->state = HC_STATE_RUNNING;
if (bus->root_hub)
usb_hcd_resume_root_hub(hcd);
return 0;
}
static int urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flags)
{
return -ENXIO;
}
static int urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
{
return -ENXIO;
}
static int get_frame_number(struct usb_hcd *hcd)
{
return 0;
}
static int hub_status_data(struct usb_hcd *hcd, char *buf)
{
return 0;
}
static int hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, u16 wIndex,
char *buf, u16 wLength)
{
struct gb_usb_hub_control_request request;
struct gb_usb_device *dev = to_gb_usb_device(hcd);
int ret;
request.typeReq = cpu_to_le16(typeReq);
request.wValue = cpu_to_le16(wValue);
request.wIndex = cpu_to_le16(wIndex);
request.wLength = cpu_to_le16(wLength);
// FIXME - buf needs to come back in struct gb_usb_hub_control_response
// for some types of requests, depending on typeReq. Do we do this in a
// "generic" way, or only ask for a response for the ones we "know" need
// a response (a small subset of all valid typeReq, thankfully.)
ret = gb_operation_sync(dev->connection, GB_USB_TYPE_HUB_CONTROL,
&request, sizeof(request), NULL, 0);
return ret;
}
static struct hc_driver usb_gb_hc_driver = {
.description = "greybus_usb",
.product_desc = "GB-Bridge USB Controller", /* TODO: Get this from GPB ?*/
.flags = HCD_MEMORY | HCD_USB2, /* FIXME: Get this from GPB */
.hcd_priv_size = sizeof(struct gb_usb_device),
.start = hcd_start,
.stop = hcd_stop,
.urb_enqueue = urb_enqueue,
.urb_dequeue = urb_dequeue,
.get_frame_number = get_frame_number,
.hub_status_data = hub_status_data,
.hub_control = hub_control,
};
static int gb_usb_connection_init(struct gb_connection *connection)
{
struct device *dev = &connection->dev;
struct gb_usb_device *gb_usb_dev;
struct usb_hcd *hcd;
int retval;
hcd = usb_create_hcd(&usb_gb_hc_driver, dev, dev_name(dev));
if (!hcd)
return -ENOMEM;
gb_usb_dev = to_gb_usb_device(hcd);
gb_usb_dev->connection = connection;
connection->private = gb_usb_dev;
/* Check for compatible protocol version */
retval = get_version(gb_usb_dev);
if (retval)
goto err_put_hcd;
hcd->has_tt = 1;
retval = usb_add_hcd(hcd, 0, 0);
if (retval)
goto err_put_hcd;
return 0;
err_put_hcd:
usb_put_hcd(hcd);
return retval;
}
static void gb_usb_connection_exit(struct gb_connection *connection)
{
struct gb_usb_device *gb_usb_dev = connection->private;
struct usb_hcd *hcd = gb_usb_device_to_hcd(gb_usb_dev);
usb_remove_hcd(hcd);
usb_put_hcd(hcd);
}
static struct gb_protocol usb_protocol = {
.name = "usb",
.id = GREYBUS_PROTOCOL_USB,
.major = 0,
.minor = 1,
.connection_init = gb_usb_connection_init,
.connection_exit = gb_usb_connection_exit,
.request_recv = NULL, /* FIXME we have requests!!! */
};
gb_builtin_protocol_driver(usb_protocol);
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