[U-Boot] [u-boot 03/40] usb: gadget: udc: add udc-core from linux kernel to u-boot

[Lukasz Majewski]

Hi Kishon,

> Added udc-core.c from linux kernel 3.19-rc1 (97bf6af1f9) to u-boot.
> This will be adapted to work with u-boot in the
> following patches.
> Adding support for udc will help to seamlessly port dwc3 driver from
> linux kernel to u-boot (since dwc3 uses udc-core) and it'll also help
> to add support for multiple gadget controllers to be functional at the
> same time.
> All other gadget drivers can also be adapted to use udc-core.
> 
> Signed-off-by: Kishon Vijay Abraham I <kishon at ti.com>
> ---
>  drivers/usb/gadget/udc/Makefile   |    4 +
>  drivers/usb/gadget/udc/udc-core.c |  637
> +++++++++++++++++++++++++++++++++++++ 2 files changed, 641
> insertions(+) create mode 100644 drivers/usb/gadget/udc/Makefile
>  create mode 100644 drivers/usb/gadget/udc/udc-core.c
> 
> diff --git a/drivers/usb/gadget/udc/Makefile
> b/drivers/usb/gadget/udc/Makefile new file mode 100644
> index 0000000..be265aa
> --- /dev/null
> +++ b/drivers/usb/gadget/udc/Makefile
> @@ -0,0 +1,4 @@
> +#
> +# USB peripheral controller drivers
> +#
> +obj-$(CONFIG_USB_GADGET)	+= udc-core.o
> diff --git a/drivers/usb/gadget/udc/udc-core.c
> b/drivers/usb/gadget/udc/udc-core.c new file mode 100644
> index 0000000..e31d574
> --- /dev/null
> +++ b/drivers/usb/gadget/udc/udc-core.c
> @@ -0,0 +1,637 @@
> +/**
> + * udc.c - Core UDC Framework
> + *
> + * Copyright (C) 2010 Texas Instruments
> + * Author: Felipe Balbi <balbi at ti.com>
> + *
> + * This program is free software: you can redistribute it and/or
> modify
> + * it under the terms of the GNU General Public License version 2  of
> + * the License as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program.  If not, see
> <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/device.h>
> +#include <linux/list.h>
> +#include <linux/err.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/workqueue.h>
> +
> +#include <linux/usb/ch9.h>
> +#include <linux/usb/gadget.h>
> +#include <linux/usb.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);
> +static DEFINE_MUTEX(udc_lock);
> +
> +/*
> -------------------------------------------------------------------------
> */ + +#ifdef	CONFIG_HAS_DMA
> +
> +int usb_gadget_map_request(struct usb_gadget *gadget,
> +		struct usb_request *req, int is_in)
> +{
> +	if (req->length == 0)
> +		return 0;
> +
> +	if (req->num_sgs) {
> +		int     mapped;
> +
> +		mapped = dma_map_sg(&gadget->dev, req->sg,
> req->num_sgs,
> +				is_in ? DMA_TO_DEVICE :
> DMA_FROM_DEVICE);
> +		if (mapped == 0) {
> +			dev_err(&gadget->dev, "failed to map SGs\n");
> +			return -EFAULT;
> +		}
> +
> +		req->num_mapped_sgs = mapped;
> +	} else {
> +		req->dma = dma_map_single(&gadget->dev, req->buf,
> req->length,
> +				is_in ? DMA_TO_DEVICE :
> DMA_FROM_DEVICE); +
> +		if (dma_mapping_error(&gadget->dev, req->dma)) {
> +			dev_err(&gadget->dev, "failed to map
> buffer\n");
> +			return -EFAULT;
> +		}
> +	}
> +
> +	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;
> +
> +	if (req->num_mapped_sgs) {
> +		dma_unmap_sg(&gadget->dev, req->sg,
> req->num_mapped_sgs,
> +				is_in ? DMA_TO_DEVICE :
> DMA_FROM_DEVICE); +
> +		req->num_mapped_sgs = 0;
> +	} else {
> +		dma_unmap_single(&gadget->dev, req->dma, req->length,
> +				is_in ? DMA_TO_DEVICE :
> DMA_FROM_DEVICE);
> +	}
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_unmap_request);
> +
> +#endif	/* CONFIG_HAS_DMA */
> +
> +/*
> -------------------------------------------------------------------------
> */ + +/**
> + * 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)
> +{
> +	if (likely(req->status == 0))
> +		usb_led_activity(USB_LED_EVENT_GADGET);
> +
> +	req->complete(ep, req);
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_giveback_request);
> +
> +/*
> -------------------------------------------------------------------------
> */ + +static void usb_gadget_state_work(struct work_struct *work)
> +{
> +	struct usb_gadget	*gadget = work_to_gadget(work);
> +	struct usb_udc		*udc = NULL;
> +
> +	mutex_lock(&udc_lock);
> +	list_for_each_entry(udc, &udc_list, list)
> +		if (udc->gadget == gadget)
> +			goto found;
> +	mutex_unlock(&udc_lock);
> +
> +	return;
> +
> +found:
> +	mutex_unlock(&udc_lock);
> +
> +	sysfs_notify(&udc->dev.kobj, NULL, "state");
> +}
> +
> +void usb_gadget_set_state(struct usb_gadget *gadget,
> +		enum usb_device_state state)
> +{
> +	gadget->state = state;
> +	schedule_work(&gadget->work);
> +}
> +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);
> +	dev_dbg(dev, "releasing '%s'\n", dev_name(dev));
> +	kfree(udc);
> +}
> +
> +static const struct attribute_group *usb_udc_attr_groups[];
> +
> +static void usb_udc_nop_release(struct device *dev)
> +{
> +	dev_vdbg(dev, "%s\n", __func__);
> +}
> +
> +/**
> + * 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");
> +	INIT_WORK(&gadget->work, usb_gadget_state_work);
> +	gadget->dev.parent = parent;
> +
> +#ifdef	CONFIG_HAS_DMA
> +	dma_set_coherent_mask(&gadget->dev,
> parent->coherent_dma_mask);
> +	gadget->dev.dma_parms = parent->dma_parms;
> +	gadget->dev.dma_mask = parent->dma_mask;
> +#endif
> +
> +	if (release)
> +		gadget->dev.release = release;
> +	else
> +		gadget->dev.release = usb_udc_nop_release;
> +
> +	ret = device_register(&gadget->dev);
> +	if (ret)
> +		goto err2;
> +
> +	device_initialize(&udc->dev);
> +	udc->dev.release = usb_udc_release;
> +	udc->dev.class = udc_class;
> +	udc->dev.groups = usb_udc_attr_groups;
> +	udc->dev.parent = parent;
> +	ret = dev_set_name(&udc->dev, "%s",
> kobject_name(&parent->kobj));
> +	if (ret)
> +		goto err3;
> +
> +	udc->gadget = gadget;
> +
> +	mutex_lock(&udc_lock);
> +	list_add_tail(&udc->list, &udc_list);
> +
> +	ret = device_add(&udc->dev);
> +	if (ret)
> +		goto err4;
> +
> +	usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED);
> +
> +	mutex_unlock(&udc_lock);
> +
> +	return 0;
> +
> +err4:
> +	list_del(&udc->list);
> +	mutex_unlock(&udc_lock);
> +
> +err3:
> +	put_device(&udc->dev);
> +
> +err2:
> +	put_device(&gadget->dev);
> +	kfree(udc);
> +
> +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);
> +
> +	kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
> +
> +	usb_gadget_disconnect(udc->gadget);
> +	udc->driver->disconnect(udc->gadget);
> +	udc->driver->unbind(udc->gadget);
> +	usb_gadget_udc_stop(udc);
> +
> +	udc->driver = NULL;
> +	udc->dev.driver = NULL;
> +	udc->gadget->dev.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);
> +
> +	kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE);
> +	flush_work(&gadget->work);
> +	device_unregister(&udc->dev);
> +	device_unregister(&gadget->dev);
> +}
> +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;
> +	udc->dev.driver = &driver->driver;
> +	udc->gadget->dev.driver = &driver->driver;
> +
> +	ret = driver->bind(udc->gadget, driver);
> +	if (ret)
> +		goto err1;
> +	ret = usb_gadget_udc_start(udc);
> +	if (ret) {
> +		driver->unbind(udc->gadget);
> +		goto err1;
> +	}
> +	usb_gadget_connect(udc->gadget);
> +
> +	kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
> +	return 0;
> +err1:
> +	if (ret != -EISNAM)
> +		dev_err(&udc->dev, "failed to start %s: %d\n",
> +			udc->driver->function, ret);
> +	udc->driver = NULL;
> +	udc->dev.driver = NULL;
> +	udc->gadget->dev.driver = NULL;
> +	return ret;
> +}
> +
> +int usb_udc_attach_driver(const char *name, struct usb_gadget_driver
> *driver) +{
> +	struct usb_udc *udc = NULL;
> +	int ret = -ENODEV;
> +
> +	mutex_lock(&udc_lock);
> +	list_for_each_entry(udc, &udc_list, list) {
> +		ret = strcmp(name, dev_name(&udc->dev));
> +		if (!ret)
> +			break;
> +	}
> +	if (ret) {
> +		ret = -ENODEV;
> +		goto out;
> +	}
> +	if (udc->driver) {
> +		ret = -EBUSY;
> +		goto out;
> +	}
> +	ret = udc_bind_to_driver(udc, driver);
> +out:
> +	mutex_unlock(&udc_lock);
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(usb_udc_attach_driver);
> +
> +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;
> +	}
> +
> +	pr_debug("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_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);
> +
> +/*
> -------------------------------------------------------------------------
> */ + +static ssize_t usb_udc_srp_store(struct device *dev,
> +		struct device_attribute *attr, const char *buf,
> size_t n) +{
> +	struct usb_udc		*udc = container_of(dev,
> struct usb_udc, dev); +
> +	if (sysfs_streq(buf, "1"))
> +		usb_gadget_wakeup(udc->gadget);
> +
> +	return n;
> +}
> +static DEVICE_ATTR(srp, S_IWUSR, NULL, usb_udc_srp_store);
> +
> +static ssize_t usb_udc_softconn_store(struct device *dev,
> +		struct device_attribute *attr, const char *buf,
> size_t n) +{
> +	struct usb_udc		*udc = container_of(dev,
> struct usb_udc, dev); +
> +	if (!udc->driver) {
> +		dev_err(dev, "soft-connect without a gadget
> driver\n");
> +		return -EOPNOTSUPP;
> +	}
> +
> +	if (sysfs_streq(buf, "connect")) {
> +		usb_gadget_udc_start(udc);
> +		usb_gadget_connect(udc->gadget);
> +	} else if (sysfs_streq(buf, "disconnect")) {
> +		usb_gadget_disconnect(udc->gadget);
> +		udc->driver->disconnect(udc->gadget);
> +		usb_gadget_udc_stop(udc);
> +	} else {
> +		dev_err(dev, "unsupported command '%s'\n", buf);
> +		return -EINVAL;
> +	}
> +
> +	return n;
> +}
> +static DEVICE_ATTR(soft_connect, S_IWUSR, NULL,
> usb_udc_softconn_store); +
> +static ssize_t state_show(struct device *dev, struct
> device_attribute *attr,
> +			  char *buf)
> +{
> +	struct usb_udc		*udc = container_of(dev,
> struct usb_udc, dev);
> +	struct usb_gadget	*gadget = udc->gadget;
> +
> +	return sprintf(buf, "%s\n", usb_state_string(gadget->state));
> +}
> +static DEVICE_ATTR_RO(state);
> +
> +#define USB_UDC_SPEED_ATTR(name,
> param)					\ +ssize_t
> name##_show(struct device
> *dev,					\
> +		struct device_attribute *attr, char
> *buf)		\
> +{
> \
> +	struct usb_udc *udc = container_of(dev, struct usb_udc,
> dev);	\
> +	return snprintf(buf, PAGE_SIZE,
> "%s\n",				\
> +
> usb_speed_string(udc->gadget->param));		\
> +}
> \ +static DEVICE_ATTR_RO(name) +
> +static USB_UDC_SPEED_ATTR(current_speed, speed);
> +static USB_UDC_SPEED_ATTR(maximum_speed, max_speed);
> +
> +#define USB_UDC_ATTR(name)					\
> +ssize_t name##_show(struct device
> *dev,				\
> +		struct device_attribute *attr, char *buf)	\
> +{								\
> +	struct usb_udc		*udc = container_of(dev,
> struct usb_udc, dev); \
> +	struct usb_gadget	*gadget =
> udc->gadget;		\
> +								\
> +	return snprintf(buf, PAGE_SIZE, "%d\n",
> gadget->name);	\
> +}								\
> +static DEVICE_ATTR_RO(name) +
> +static USB_UDC_ATTR(is_otg);
> +static USB_UDC_ATTR(is_a_peripheral);
> +static USB_UDC_ATTR(b_hnp_enable);
> +static USB_UDC_ATTR(a_hnp_support);
> +static USB_UDC_ATTR(a_alt_hnp_support);
> +
> +static struct attribute *usb_udc_attrs[] = {
> +	&dev_attr_srp.attr,
> +	&dev_attr_soft_connect.attr,
> +	&dev_attr_state.attr,
> +	&dev_attr_current_speed.attr,
> +	&dev_attr_maximum_speed.attr,
> +
> +	&dev_attr_is_otg.attr,
> +	&dev_attr_is_a_peripheral.attr,
> +	&dev_attr_b_hnp_enable.attr,
> +	&dev_attr_a_hnp_support.attr,
> +	&dev_attr_a_alt_hnp_support.attr,
> +	NULL,
> +};
> +
> +static const struct attribute_group usb_udc_attr_group = {
> +	.attrs = usb_udc_attrs,
> +};
> +
> +static const struct attribute_group *usb_udc_attr_groups[] = {
> +	&usb_udc_attr_group,
> +	NULL,
> +};
> +
> +static int usb_udc_uevent(struct device *dev, struct kobj_uevent_env
> *env) +{
> +	struct usb_udc		*udc = container_of(dev,
> struct usb_udc, dev);
> +	int			ret;
> +
> +	ret = add_uevent_var(env, "USB_UDC_NAME=%s",
> udc->gadget->name);
> +	if (ret) {
> +		dev_err(dev, "failed to add uevent USB_UDC_NAME\n");
> +		return ret;
> +	}
> +
> +	if (udc->driver) {
> +		ret = add_uevent_var(env, "USB_UDC_DRIVER=%s",
> +				udc->driver->function);
> +		if (ret) {
> +			dev_err(dev, "failed to add uevent
> USB_UDC_DRIVER\n");
> +			return ret;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static int __init usb_udc_init(void)
> +{
> +	udc_class = class_create(THIS_MODULE, "udc");
> +	if (IS_ERR(udc_class)) {
> +		pr_err("failed to create udc class --> %ld\n",
> +				PTR_ERR(udc_class));
> +		return PTR_ERR(udc_class);
> +	}
> +
> +	udc_class->dev_uevent = usb_udc_uevent;
> +	return 0;
> +}
> +subsys_initcall(usb_udc_init);
> +
> +static void __exit usb_udc_exit(void)
> +{
> +	class_destroy(udc_class);
> +}
> +module_exit(usb_udc_exit);
> +
> +MODULE_DESCRIPTION("UDC Framework");
> +MODULE_AUTHOR("Felipe Balbi <balbi at ti.com>");
> +MODULE_LICENSE("GPL v2");

Since this code was taken from a linux kernel I don't have any comments
:-)

However, I will thest this series to asses if it works with Odroid-XU3,
since it also uses DWC3.


-- 
Best regards,

Lukasz Majewski

Samsung R&D Institute Poland (SRPOL) | Linux Platform Group