/**
* udc.c - Core UDC Framework
*
* Copyright (C) 2010 Texas Instruments
* Author: Felipe Balbi <balbi@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/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);
static 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;
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);
/* ------------------------------------------------------------------------- */
void usb_gadget_set_state(struct usb_gadget *gadget,
enum usb_device_state state)
{
gadget->state = state;
sysfs_notify(&gadget->dev.kobj, NULL, "status");
}
EXPORT_SYMBOL_GPL(usb_gadget_set_state);
/* ------------------------------------------------------------------------- */
/**
* usb_gadget_udc_start - tells usb device controller to start up
* @gadget: The gadget we want to get started
* @driver: The driver we want to bind to @gadget
*
* 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_gadget *gadget,
struct usb_gadget_driver *driver)
{
return gadget->ops->udc_start(gadget, 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_gadget *gadget,
struct usb_gadget_driver *driver)
{
gadget->ops->udc_stop(gadget, driver);
}
/**
* 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");
gadget->dev.parent = parent;
dma_set_coherent_mask(&gadget->dev, parent->coherent_dma_mask);
gadget->dev.dma_parms = parent->dma_parms;
gadget->dev.dma_mask = parent->dma_mask;
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);
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->gadget->name);
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->gadget, udc->driver);
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);
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->gadget, driver);
if (ret) {
driver->unbind(udc->gadget);
goto err1;
}
usb_gadget_connect(udc->gadget);
kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
return 0;
err1:
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 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(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);
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 (sysfs_streq(buf, "connect")) {
usb_gadget_udc_start(udc->gadget, udc->driver);
usb_gadget_connect(udc->gadget);
} else if (sysfs_streq(buf, "disconnect")) {
usb_gadget_disconnect(udc->gadget);
usb_gadget_udc_stop(udc->gadget, udc->driver);
} 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 usb_gadget_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(state, S_IRUGO, usb_gadget_state_show, NULL);
#define USB_UDC_SPEED_ATTR(name, param) \
ssize_t usb_udc_##param##_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(name, S_IRUGO, usb_udc_##param##_show, NULL)
static USB_UDC_SPEED_ATTR(current_speed, speed);
static USB_UDC_SPEED_ATTR(maximum_speed, max_speed);
#define USB_UDC_ATTR(name) \
ssize_t usb_udc_##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(name, S_IRUGO, usb_udc_##name##_show, NULL)
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@ti.com>");
MODULE_LICENSE("GPL v2");
