![Fabio Estevam](/assets/img/avatar_default.png)
When mounting a gadgetfs the following error message is seen: $ modprobe gadgetfs gadgetfs: USB Gadget filesystem, version 24 Aug 2004 $ mkdir /dev/gadget $ mount -t gadgetfs none /dev/gadget nop ci_hdrc.0: failed to start (null): -120 The error comes from gadgetfs_probe(), which returns -EISNAM (-120). As Alan Stern explains[1], this is the normal behavior: "It is a temporary measure, used only when the file system is set up initially. The real bind routine is gadgetfs_bind(), which gets called when userspace configures the gadget. In short, this is how it is intended to work. It isn't a bug." [1] http://marc.info/?l=linux-usb&m=138029668707075&w=2 So in order to prevent the error message, do not report EISNAM as an error. Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Signed-off-by: Felipe Balbi <balbi@ti.com>
584 lines
14 KiB
C
584 lines
14 KiB
C
/**
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* udc.c - Core UDC Framework
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*
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* Copyright (C) 2010 Texas Instruments
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* Author: Felipe Balbi <balbi@ti.com>
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 of
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* the License as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/device.h>
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#include <linux/list.h>
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#include <linux/err.h>
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#include <linux/dma-mapping.h>
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#include <linux/workqueue.h>
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#include <linux/usb/ch9.h>
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#include <linux/usb/gadget.h>
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/**
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* struct usb_udc - describes one usb device controller
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* @driver - the gadget driver pointer. For use by the class code
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* @dev - the child device to the actual controller
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* @gadget - the gadget. For use by the class code
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* @list - for use by the udc class driver
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*
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* This represents the internal data structure which is used by the UDC-class
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* to hold information about udc driver and gadget together.
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*/
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struct usb_udc {
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struct usb_gadget_driver *driver;
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struct usb_gadget *gadget;
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struct device dev;
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struct list_head list;
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};
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static struct class *udc_class;
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static LIST_HEAD(udc_list);
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static DEFINE_MUTEX(udc_lock);
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/* ------------------------------------------------------------------------- */
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#ifdef CONFIG_HAS_DMA
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int usb_gadget_map_request(struct usb_gadget *gadget,
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struct usb_request *req, int is_in)
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{
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if (req->length == 0)
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return 0;
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if (req->num_sgs) {
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int mapped;
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mapped = dma_map_sg(&gadget->dev, req->sg, req->num_sgs,
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is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
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if (mapped == 0) {
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dev_err(&gadget->dev, "failed to map SGs\n");
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return -EFAULT;
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}
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req->num_mapped_sgs = mapped;
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} else {
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req->dma = dma_map_single(&gadget->dev, req->buf, req->length,
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is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
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if (dma_mapping_error(&gadget->dev, req->dma)) {
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dev_err(&gadget->dev, "failed to map buffer\n");
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return -EFAULT;
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}
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}
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return 0;
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}
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EXPORT_SYMBOL_GPL(usb_gadget_map_request);
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void usb_gadget_unmap_request(struct usb_gadget *gadget,
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struct usb_request *req, int is_in)
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{
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if (req->length == 0)
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return;
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if (req->num_mapped_sgs) {
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dma_unmap_sg(&gadget->dev, req->sg, req->num_mapped_sgs,
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is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
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req->num_mapped_sgs = 0;
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} else {
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dma_unmap_single(&gadget->dev, req->dma, req->length,
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is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
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}
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}
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EXPORT_SYMBOL_GPL(usb_gadget_unmap_request);
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#endif /* CONFIG_HAS_DMA */
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/* ------------------------------------------------------------------------- */
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static void usb_gadget_state_work(struct work_struct *work)
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{
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struct usb_gadget *gadget = work_to_gadget(work);
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sysfs_notify(&gadget->dev.kobj, NULL, "state");
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}
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void usb_gadget_set_state(struct usb_gadget *gadget,
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enum usb_device_state state)
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{
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gadget->state = state;
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schedule_work(&gadget->work);
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}
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EXPORT_SYMBOL_GPL(usb_gadget_set_state);
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/* ------------------------------------------------------------------------- */
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/**
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* usb_gadget_udc_start - tells usb device controller to start up
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* @gadget: The gadget we want to get started
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* @driver: The driver we want to bind to @gadget
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*
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* This call is issued by the UDC Class driver when it's about
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* to register a gadget driver to the device controller, before
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* calling gadget driver's bind() method.
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*
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* It allows the controller to be powered off until strictly
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* necessary to have it powered on.
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*
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* Returns zero on success, else negative errno.
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*/
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static inline int usb_gadget_udc_start(struct usb_gadget *gadget,
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struct usb_gadget_driver *driver)
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{
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return gadget->ops->udc_start(gadget, driver);
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}
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/**
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* usb_gadget_udc_stop - tells usb device controller we don't need it anymore
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* @gadget: The device we want to stop activity
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* @driver: The driver to unbind from @gadget
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*
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* This call is issued by the UDC Class driver after calling
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* gadget driver's unbind() method.
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*
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* The details are implementation specific, but it can go as
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* far as powering off UDC completely and disable its data
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* line pullups.
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*/
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static inline void usb_gadget_udc_stop(struct usb_gadget *gadget,
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struct usb_gadget_driver *driver)
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{
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gadget->ops->udc_stop(gadget, driver);
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}
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/**
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* usb_udc_release - release the usb_udc struct
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* @dev: the dev member within usb_udc
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*
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* This is called by driver's core in order to free memory once the last
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* reference is released.
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*/
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static void usb_udc_release(struct device *dev)
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{
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struct usb_udc *udc;
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udc = container_of(dev, struct usb_udc, dev);
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dev_dbg(dev, "releasing '%s'\n", dev_name(dev));
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kfree(udc);
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}
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static const struct attribute_group *usb_udc_attr_groups[];
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static void usb_udc_nop_release(struct device *dev)
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{
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dev_vdbg(dev, "%s\n", __func__);
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}
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/**
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* usb_add_gadget_udc_release - adds a new gadget to the udc class driver list
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* @parent: the parent device to this udc. Usually the controller driver's
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* device.
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* @gadget: the gadget to be added to the list.
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* @release: a gadget release function.
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*
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* Returns zero on success, negative errno otherwise.
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*/
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int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
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void (*release)(struct device *dev))
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{
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struct usb_udc *udc;
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int ret = -ENOMEM;
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udc = kzalloc(sizeof(*udc), GFP_KERNEL);
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if (!udc)
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goto err1;
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dev_set_name(&gadget->dev, "gadget");
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INIT_WORK(&gadget->work, usb_gadget_state_work);
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gadget->dev.parent = parent;
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#ifdef CONFIG_HAS_DMA
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dma_set_coherent_mask(&gadget->dev, parent->coherent_dma_mask);
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gadget->dev.dma_parms = parent->dma_parms;
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gadget->dev.dma_mask = parent->dma_mask;
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#endif
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if (release)
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gadget->dev.release = release;
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else
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gadget->dev.release = usb_udc_nop_release;
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ret = device_register(&gadget->dev);
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if (ret)
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goto err2;
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device_initialize(&udc->dev);
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udc->dev.release = usb_udc_release;
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udc->dev.class = udc_class;
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udc->dev.groups = usb_udc_attr_groups;
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udc->dev.parent = parent;
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ret = dev_set_name(&udc->dev, "%s", kobject_name(&parent->kobj));
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if (ret)
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goto err3;
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udc->gadget = gadget;
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mutex_lock(&udc_lock);
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list_add_tail(&udc->list, &udc_list);
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ret = device_add(&udc->dev);
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if (ret)
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goto err4;
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usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED);
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mutex_unlock(&udc_lock);
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return 0;
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err4:
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list_del(&udc->list);
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mutex_unlock(&udc_lock);
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err3:
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put_device(&udc->dev);
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err2:
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put_device(&gadget->dev);
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kfree(udc);
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err1:
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return ret;
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}
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EXPORT_SYMBOL_GPL(usb_add_gadget_udc_release);
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/**
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* usb_add_gadget_udc - adds a new gadget to the udc class driver list
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* @parent: the parent device to this udc. Usually the controller
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* driver's device.
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* @gadget: the gadget to be added to the list
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*
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* Returns zero on success, negative errno otherwise.
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*/
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int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget)
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{
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return usb_add_gadget_udc_release(parent, gadget, NULL);
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}
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EXPORT_SYMBOL_GPL(usb_add_gadget_udc);
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static void usb_gadget_remove_driver(struct usb_udc *udc)
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{
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dev_dbg(&udc->dev, "unregistering UDC driver [%s]\n",
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udc->gadget->name);
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kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
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usb_gadget_disconnect(udc->gadget);
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udc->driver->disconnect(udc->gadget);
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udc->driver->unbind(udc->gadget);
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usb_gadget_udc_stop(udc->gadget, NULL);
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udc->driver = NULL;
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udc->dev.driver = NULL;
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udc->gadget->dev.driver = NULL;
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}
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/**
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* usb_del_gadget_udc - deletes @udc from udc_list
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* @gadget: the gadget to be removed.
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*
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* This, will call usb_gadget_unregister_driver() if
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* the @udc is still busy.
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*/
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void usb_del_gadget_udc(struct usb_gadget *gadget)
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{
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struct usb_udc *udc = NULL;
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mutex_lock(&udc_lock);
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list_for_each_entry(udc, &udc_list, list)
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if (udc->gadget == gadget)
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goto found;
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dev_err(gadget->dev.parent, "gadget not registered.\n");
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mutex_unlock(&udc_lock);
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return;
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found:
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dev_vdbg(gadget->dev.parent, "unregistering gadget\n");
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list_del(&udc->list);
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mutex_unlock(&udc_lock);
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if (udc->driver)
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usb_gadget_remove_driver(udc);
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kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE);
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flush_work(&gadget->work);
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device_unregister(&udc->dev);
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device_unregister(&gadget->dev);
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}
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EXPORT_SYMBOL_GPL(usb_del_gadget_udc);
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/* ------------------------------------------------------------------------- */
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static int udc_bind_to_driver(struct usb_udc *udc, struct usb_gadget_driver *driver)
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{
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int ret;
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dev_dbg(&udc->dev, "registering UDC driver [%s]\n",
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driver->function);
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udc->driver = driver;
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udc->dev.driver = &driver->driver;
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udc->gadget->dev.driver = &driver->driver;
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ret = driver->bind(udc->gadget, driver);
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if (ret)
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goto err1;
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ret = usb_gadget_udc_start(udc->gadget, driver);
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if (ret) {
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driver->unbind(udc->gadget);
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goto err1;
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}
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usb_gadget_connect(udc->gadget);
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kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
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return 0;
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err1:
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if (ret != -EISNAM)
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dev_err(&udc->dev, "failed to start %s: %d\n",
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udc->driver->function, ret);
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udc->driver = NULL;
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udc->dev.driver = NULL;
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udc->gadget->dev.driver = NULL;
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return ret;
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}
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int udc_attach_driver(const char *name, struct usb_gadget_driver *driver)
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{
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struct usb_udc *udc = NULL;
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int ret = -ENODEV;
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mutex_lock(&udc_lock);
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list_for_each_entry(udc, &udc_list, list) {
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ret = strcmp(name, dev_name(&udc->dev));
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if (!ret)
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break;
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}
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if (ret) {
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ret = -ENODEV;
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goto out;
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}
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if (udc->driver) {
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ret = -EBUSY;
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goto out;
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}
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ret = udc_bind_to_driver(udc, driver);
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out:
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mutex_unlock(&udc_lock);
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return ret;
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}
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EXPORT_SYMBOL_GPL(udc_attach_driver);
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int usb_gadget_probe_driver(struct usb_gadget_driver *driver)
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{
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struct usb_udc *udc = NULL;
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int ret;
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if (!driver || !driver->bind || !driver->setup)
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return -EINVAL;
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mutex_lock(&udc_lock);
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list_for_each_entry(udc, &udc_list, list) {
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/* For now we take the first one */
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if (!udc->driver)
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goto found;
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}
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pr_debug("couldn't find an available UDC\n");
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mutex_unlock(&udc_lock);
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return -ENODEV;
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found:
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ret = udc_bind_to_driver(udc, driver);
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mutex_unlock(&udc_lock);
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return ret;
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}
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EXPORT_SYMBOL_GPL(usb_gadget_probe_driver);
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int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
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{
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struct usb_udc *udc = NULL;
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int ret = -ENODEV;
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if (!driver || !driver->unbind)
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return -EINVAL;
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mutex_lock(&udc_lock);
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list_for_each_entry(udc, &udc_list, list)
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if (udc->driver == driver) {
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usb_gadget_remove_driver(udc);
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ret = 0;
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break;
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}
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mutex_unlock(&udc_lock);
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return ret;
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}
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EXPORT_SYMBOL_GPL(usb_gadget_unregister_driver);
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|
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/* ------------------------------------------------------------------------- */
|
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|
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static ssize_t usb_udc_srp_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t n)
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{
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struct usb_udc *udc = container_of(dev, struct usb_udc, dev);
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|
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if (sysfs_streq(buf, "1"))
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usb_gadget_wakeup(udc->gadget);
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return n;
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}
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static DEVICE_ATTR(srp, S_IWUSR, NULL, usb_udc_srp_store);
|
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|
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static ssize_t usb_udc_softconn_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t n)
|
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{
|
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struct usb_udc *udc = container_of(dev, struct usb_udc, dev);
|
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|
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if (sysfs_streq(buf, "connect")) {
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usb_gadget_udc_start(udc->gadget, udc->driver);
|
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usb_gadget_connect(udc->gadget);
|
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} else if (sysfs_streq(buf, "disconnect")) {
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usb_gadget_disconnect(udc->gadget);
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usb_gadget_udc_stop(udc->gadget, udc->driver);
|
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} else {
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dev_err(dev, "unsupported command '%s'\n", buf);
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return -EINVAL;
|
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}
|
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|
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return n;
|
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}
|
|
static DEVICE_ATTR(soft_connect, S_IWUSR, NULL, usb_udc_softconn_store);
|
|
|
|
static ssize_t state_show(struct device *dev, struct device_attribute *attr,
|
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char *buf)
|
|
{
|
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struct usb_udc *udc = container_of(dev, struct usb_udc, dev);
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struct usb_gadget *gadget = udc->gadget;
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|
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return sprintf(buf, "%s\n", usb_state_string(gadget->state));
|
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}
|
|
static DEVICE_ATTR_RO(state);
|
|
|
|
#define USB_UDC_SPEED_ATTR(name, param) \
|
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ssize_t name##_show(struct device *dev, \
|
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struct device_attribute *attr, char *buf) \
|
|
{ \
|
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struct usb_udc *udc = container_of(dev, struct usb_udc, dev); \
|
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return snprintf(buf, PAGE_SIZE, "%s\n", \
|
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usb_speed_string(udc->gadget->param)); \
|
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} \
|
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static DEVICE_ATTR_RO(name)
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|
|
static USB_UDC_SPEED_ATTR(current_speed, speed);
|
|
static USB_UDC_SPEED_ATTR(maximum_speed, max_speed);
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|
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|
#define USB_UDC_ATTR(name) \
|
|
ssize_t name##_show(struct device *dev, \
|
|
struct device_attribute *attr, char *buf) \
|
|
{ \
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|
struct usb_udc *udc = container_of(dev, struct usb_udc, dev); \
|
|
struct usb_gadget *gadget = udc->gadget; \
|
|
\
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|
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);
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|
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");
|