u-boot/drivers/usb/gadget/udc/udc-core.c

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/**
* udc-core.c - Core UDC Framework
*
* Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
*
* Author: Felipe Balbi <balbi@ti.com>
*
* Taken from Linux Kernel v3.19-rc1 (drivers/usb/gadget/udc-core.c) and ported
* to uboot.
*
* commit 02e8c96627 : usb: gadget: udc: core: prepend udc_attach_driver with
* usb_
*
* SPDX-License-Identifier: GPL-2.0
*/
#include <linux/compat.h>
#include <malloc.h>
#include <asm/cache.h>
#include <asm/dma-mapping.h>
#include <common.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
/**
* struct usb_udc - describes one usb device controller
* @driver - the gadget driver pointer. For use by the class code
* @dev - the child device to the actual controller
* @gadget - the gadget. For use by the class code
* @list - for use by the udc class driver
*
* This represents the internal data structure which is used by the UDC-class
* to hold information about udc driver and gadget together.
*/
struct usb_udc {
struct usb_gadget_driver *driver;
struct usb_gadget *gadget;
struct device dev;
struct list_head list;
};
static struct class *udc_class;
static LIST_HEAD(udc_list);
DEFINE_MUTEX(udc_lock);
/* ------------------------------------------------------------------------- */
int usb_gadget_map_request(struct usb_gadget *gadget,
struct usb_request *req, int is_in)
{
if (req->length == 0)
return 0;
req->dma = dma_map_single(req->buf, req->length,
is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
return 0;
}
EXPORT_SYMBOL_GPL(usb_gadget_map_request);
void usb_gadget_unmap_request(struct usb_gadget *gadget,
struct usb_request *req, int is_in)
{
if (req->length == 0)
return;
dma_unmap_single((void *)(uintptr_t)req->dma, req->length,
is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
}
EXPORT_SYMBOL_GPL(usb_gadget_unmap_request);
/* ------------------------------------------------------------------------- */
/**
* usb_gadget_giveback_request - give the request back to the gadget layer
* Context: in_interrupt()
*
* This is called by device controller drivers in order to return the
* completed request back to the gadget layer.
*/
void usb_gadget_giveback_request(struct usb_ep *ep,
struct usb_request *req)
{
req->complete(ep, req);
}
EXPORT_SYMBOL_GPL(usb_gadget_giveback_request);
/* ------------------------------------------------------------------------- */
void usb_gadget_set_state(struct usb_gadget *gadget,
enum usb_device_state state)
{
gadget->state = state;
}
EXPORT_SYMBOL_GPL(usb_gadget_set_state);
/* ------------------------------------------------------------------------- */
/**
* usb_gadget_udc_reset - notifies the udc core that bus reset occurs
* @gadget: The gadget which bus reset occurs
* @driver: The gadget driver we want to notify
*
* If the udc driver has bus reset handler, it needs to call this when the bus
* reset occurs, it notifies the gadget driver that the bus reset occurs as
* well as updates gadget state.
*/
void usb_gadget_udc_reset(struct usb_gadget *gadget,
struct usb_gadget_driver *driver)
{
driver->reset(gadget);
usb_gadget_set_state(gadget, USB_STATE_DEFAULT);
}
EXPORT_SYMBOL_GPL(usb_gadget_udc_reset);
/**
* usb_gadget_udc_start - tells usb device controller to start up
* @udc: The UDC to be started
*
* This call is issued by the UDC Class driver when it's about
* to register a gadget driver to the device controller, before
* calling gadget driver's bind() method.
*
* It allows the controller to be powered off until strictly
* necessary to have it powered on.
*
* Returns zero on success, else negative errno.
*/
static inline int usb_gadget_udc_start(struct usb_udc *udc)
{
return udc->gadget->ops->udc_start(udc->gadget, udc->driver);
}
/**
* usb_gadget_udc_stop - tells usb device controller we don't need it anymore
* @gadget: The device we want to stop activity
* @driver: The driver to unbind from @gadget
*
* This call is issued by the UDC Class driver after calling
* gadget driver's unbind() method.
*
* The details are implementation specific, but it can go as
* far as powering off UDC completely and disable its data
* line pullups.
*/
static inline void usb_gadget_udc_stop(struct usb_udc *udc)
{
udc->gadget->ops->udc_stop(udc->gadget);
}
/**
* usb_udc_release - release the usb_udc struct
* @dev: the dev member within usb_udc
*
* This is called by driver's core in order to free memory once the last
* reference is released.
*/
static void usb_udc_release(struct device *dev)
{
struct usb_udc *udc;
udc = container_of(dev, struct usb_udc, dev);
kfree(udc);
}
/**
* usb_add_gadget_udc_release - adds a new gadget to the udc class driver list
* @parent: the parent device to this udc. Usually the controller driver's
* device.
* @gadget: the gadget to be added to the list.
* @release: a gadget release function.
*
* Returns zero on success, negative errno otherwise.
*/
int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
void (*release)(struct device *dev))
{
struct usb_udc *udc;
int ret = -ENOMEM;
udc = kzalloc(sizeof(*udc), GFP_KERNEL);
if (!udc)
goto err1;
dev_set_name(&gadget->dev, "gadget");
gadget->dev.parent = parent;
udc->dev.release = usb_udc_release;
udc->dev.class = udc_class;
udc->dev.parent = parent;
udc->gadget = gadget;
mutex_lock(&udc_lock);
list_add_tail(&udc->list, &udc_list);
usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED);
mutex_unlock(&udc_lock);
return 0;
err1:
return ret;
}
EXPORT_SYMBOL_GPL(usb_add_gadget_udc_release);
/**
* usb_add_gadget_udc - adds a new gadget to the udc class driver list
* @parent: the parent device to this udc. Usually the controller
* driver's device.
* @gadget: the gadget to be added to the list
*
* Returns zero on success, negative errno otherwise.
*/
int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget)
{
return usb_add_gadget_udc_release(parent, gadget, NULL);
}
EXPORT_SYMBOL_GPL(usb_add_gadget_udc);
static void usb_gadget_remove_driver(struct usb_udc *udc)
{
dev_dbg(&udc->dev, "unregistering UDC driver [%s]\n",
udc->driver->function);
usb_gadget_disconnect(udc->gadget);
udc->driver->disconnect(udc->gadget);
udc->driver->unbind(udc->gadget);
usb_gadget_udc_stop(udc);
udc->driver = NULL;
}
/**
* usb_del_gadget_udc - deletes @udc from udc_list
* @gadget: the gadget to be removed.
*
* This, will call usb_gadget_unregister_driver() if
* the @udc is still busy.
*/
void usb_del_gadget_udc(struct usb_gadget *gadget)
{
struct usb_udc *udc = NULL;
mutex_lock(&udc_lock);
list_for_each_entry(udc, &udc_list, list)
if (udc->gadget == gadget)
goto found;
dev_err(gadget->dev.parent, "gadget not registered.\n");
mutex_unlock(&udc_lock);
return;
found:
dev_vdbg(gadget->dev.parent, "unregistering gadget\n");
list_del(&udc->list);
mutex_unlock(&udc_lock);
if (udc->driver)
usb_gadget_remove_driver(udc);
}
EXPORT_SYMBOL_GPL(usb_del_gadget_udc);
/* ------------------------------------------------------------------------- */
static int udc_bind_to_driver(struct usb_udc *udc, struct usb_gadget_driver *driver)
{
int ret;
dev_dbg(&udc->dev, "registering UDC driver [%s]\n",
driver->function);
udc->driver = driver;
ret = driver->bind(udc->gadget);
if (ret)
goto err1;
ret = usb_gadget_udc_start(udc);
if (ret) {
driver->unbind(udc->gadget);
goto err1;
}
usb_gadget_connect(udc->gadget);
return 0;
err1:
if (ret != -EISNAM)
dev_err(&udc->dev, "failed to start %s: %d\n",
udc->driver->function, ret);
udc->driver = NULL;
return ret;
}
int usb_gadget_probe_driver(struct usb_gadget_driver *driver)
{
struct usb_udc *udc = NULL;
int ret;
if (!driver || !driver->bind || !driver->setup)
return -EINVAL;
mutex_lock(&udc_lock);
list_for_each_entry(udc, &udc_list, list) {
/* For now we take the first one */
if (!udc->driver)
goto found;
}
printf("couldn't find an available UDC\n");
mutex_unlock(&udc_lock);
return -ENODEV;
found:
ret = udc_bind_to_driver(udc, driver);
mutex_unlock(&udc_lock);
return ret;
}
EXPORT_SYMBOL_GPL(usb_gadget_probe_driver);
int usb_gadget_register_driver(struct usb_gadget_driver *driver)
{
return usb_gadget_probe_driver(driver);
}
EXPORT_SYMBOL_GPL(usb_gadget_register_driver);
int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
{
struct usb_udc *udc = NULL;
int ret = -ENODEV;
if (!driver || !driver->unbind)
return -EINVAL;
mutex_lock(&udc_lock);
list_for_each_entry(udc, &udc_list, list)
if (udc->driver == driver) {
usb_gadget_remove_driver(udc);
usb_gadget_set_state(udc->gadget,
USB_STATE_NOTATTACHED);
ret = 0;
break;
}
mutex_unlock(&udc_lock);
return ret;
}
EXPORT_SYMBOL_GPL(usb_gadget_unregister_driver);
MODULE_DESCRIPTION("UDC Framework");
MODULE_AUTHOR("Felipe Balbi <balbi@ti.com>");
MODULE_LICENSE("GPL v2");