diff options
| -rw-r--r-- | drivers/usb/gadget/function/f_hid.c | 273 | ||||
| -rw-r--r-- | include/uapi/linux/usb/g_hid.h | 40 | ||||
| -rw-r--r-- | include/uapi/linux/usb/gadgetfs.h | 2 |
3 files changed, 307 insertions, 8 deletions
diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c index 93dae017ae45..82c7dff6de5c 100644 --- a/drivers/usb/gadget/function/f_hid.c +++ b/drivers/usb/gadget/function/f_hid.c @@ -15,13 +15,21 @@ #include <linux/uaccess.h> #include <linux/wait.h> #include <linux/sched.h> +#include <linux/workqueue.h> #include <linux/usb/g_hid.h> +#include <uapi/linux/usb/g_hid.h> #include "u_f.h" #include "u_hid.h" #define HIDG_MINORS 4 +/* + * Most operating systems seem to allow for 5000ms timeout, we will allow + * userspace half that time to respond before we return an empty report. + */ +#define GET_REPORT_TIMEOUT_MS 2500 + static int major, minors; static const struct class hidg_class = { @@ -31,6 +39,11 @@ static const struct class hidg_class = { static DEFINE_IDA(hidg_ida); static DEFINE_MUTEX(hidg_ida_lock); /* protects access to hidg_ida */ +struct report_entry { + struct usb_hidg_report report_data; + struct list_head node; +}; + /*-------------------------------------------------------------------------*/ /* HID gadget struct */ @@ -75,6 +88,19 @@ struct f_hidg { wait_queue_head_t write_queue; struct usb_request *req; + /* get report */ + struct usb_request *get_req; + struct usb_hidg_report get_report; + bool get_report_returned; + int get_report_req_report_id; + int get_report_req_report_length; + spinlock_t get_report_spinlock; + wait_queue_head_t get_queue; /* Waiting for userspace response */ + wait_queue_head_t get_id_queue; /* Get ID came in */ + struct work_struct work; + struct workqueue_struct *workqueue; + struct list_head report_list; + struct device dev; struct cdev cdev; struct usb_function func; @@ -524,6 +550,174 @@ release_write_pending: return status; } +static struct report_entry *f_hidg_search_for_report(struct f_hidg *hidg, u8 report_id) +{ + struct list_head *ptr; + struct report_entry *entry; + + list_for_each(ptr, &hidg->report_list) { + entry = list_entry(ptr, struct report_entry, node); + if (entry->report_data.report_id == report_id) + return entry; + } + + return NULL; +} + +static void get_report_workqueue_handler(struct work_struct *work) +{ + struct f_hidg *hidg = container_of(work, struct f_hidg, work); + struct usb_composite_dev *cdev = hidg->func.config->cdev; + struct usb_request *req; + struct report_entry *ptr; + unsigned long flags; + + int status = 0; + + spin_lock_irqsave(&hidg->get_report_spinlock, flags); + req = hidg->get_req; + if (!req) { + spin_unlock_irqrestore(&hidg->get_report_spinlock, flags); + return; + } + + req->zero = 0; + req->length = min_t(unsigned int, min_t(unsigned int, hidg->get_report_req_report_length, + hidg->report_length), + MAX_REPORT_LENGTH); + + /* Check if there is a response available for immediate response */ + ptr = f_hidg_search_for_report(hidg, hidg->get_report_req_report_id); + if (ptr && !ptr->report_data.userspace_req) { + /* Report exists in list and it is to be used for immediate response */ + req->buf = ptr->report_data.data; + status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC); + hidg->get_report_returned = true; + spin_unlock_irqrestore(&hidg->get_report_spinlock, flags); + } else { + /* + * Report does not exist in list or should not be immediately sent + * i.e. give userspace time to respond + */ + hidg->get_report_returned = false; + spin_unlock_irqrestore(&hidg->get_report_spinlock, flags); + wake_up(&hidg->get_id_queue); +#define GET_REPORT_COND (!hidg->get_report_returned) + /* Wait until userspace has responded or timeout */ + status = wait_event_interruptible_timeout(hidg->get_queue, !GET_REPORT_COND, + msecs_to_jiffies(GET_REPORT_TIMEOUT_MS)); + spin_lock_irqsave(&hidg->get_report_spinlock, flags); + req = hidg->get_req; + if (!req) { + spin_unlock_irqrestore(&hidg->get_report_spinlock, flags); + return; + } + if (status == 0 && !hidg->get_report_returned) { + /* GET_REPORT request was not serviced by userspace within timeout period */ + VDBG(cdev, "get_report : userspace timeout.\n"); + hidg->get_report_returned = true; + } + + /* Search again for report ID in list and respond to GET_REPORT request */ + ptr = f_hidg_search_for_report(hidg, hidg->get_report_req_report_id); + if (ptr) { + /* + * Either get an updated response just serviced by userspace + * or send the latest response in the list + */ + req->buf = ptr->report_data.data; + } else { + /* If there are no prevoiusly sent reports send empty report */ + req->buf = hidg->get_report.data; + memset(req->buf, 0x0, req->length); + } + + status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC); + spin_unlock_irqrestore(&hidg->get_report_spinlock, flags); + } + + if (status < 0) + VDBG(cdev, "usb_ep_queue error on ep0 responding to GET_REPORT\n"); +} + +static int f_hidg_get_report_id(struct file *file, __u8 __user *buffer) +{ + struct f_hidg *hidg = file->private_data; + int ret = 0; + + ret = put_user(hidg->get_report_req_report_id, buffer); + + return ret; +} + +static int f_hidg_get_report(struct file *file, struct usb_hidg_report __user *buffer) +{ + struct f_hidg *hidg = file->private_data; + struct usb_composite_dev *cdev = hidg->func.config->cdev; + unsigned long flags; + struct report_entry *entry; + struct report_entry *ptr; + __u8 report_id; + + entry = kmalloc(sizeof(*entry), GFP_KERNEL); + if (!entry) + return -ENOMEM; + + if (copy_from_user(&entry->report_data, buffer, + sizeof(struct usb_hidg_report))) { + ERROR(cdev, "copy_from_user error\n"); + kfree(entry); + return -EINVAL; + } + + report_id = entry->report_data.report_id; + + spin_lock_irqsave(&hidg->get_report_spinlock, flags); + ptr = f_hidg_search_for_report(hidg, report_id); + + if (ptr) { + /* Report already exists in list - update it */ + if (copy_from_user(&ptr->report_data, buffer, + sizeof(struct usb_hidg_report))) { + spin_unlock_irqrestore(&hidg->get_report_spinlock, flags); + ERROR(cdev, "copy_from_user error\n"); + kfree(entry); + return -EINVAL; + } + kfree(entry); + } else { + /* Report does not exist in list - add it */ + list_add_tail(&entry->node, &hidg->report_list); + } + + /* If there is no response pending then do nothing further */ + if (hidg->get_report_returned) { + spin_unlock_irqrestore(&hidg->get_report_spinlock, flags); + return 0; + } + + /* If this userspace response serves the current pending report */ + if (hidg->get_report_req_report_id == report_id) { + hidg->get_report_returned = true; + wake_up(&hidg->get_queue); + } + + spin_unlock_irqrestore(&hidg->get_report_spinlock, flags); + return 0; +} + +static long f_hidg_ioctl(struct file *file, unsigned int code, unsigned long arg) +{ + switch (code) { + case GADGET_HID_READ_GET_REPORT_ID: + return f_hidg_get_report_id(file, (__u8 __user *)arg); + case GADGET_HID_WRITE_GET_REPORT: + return f_hidg_get_report(file, (struct usb_hidg_report __user *)arg); + default: + return -ENOTTY; + } +} + static __poll_t f_hidg_poll(struct file *file, poll_table *wait) { struct f_hidg *hidg = file->private_data; @@ -531,6 +725,8 @@ static __poll_t f_hidg_poll(struct file *file, poll_table *wait) poll_wait(file, &hidg->read_queue, wait); poll_wait(file, &hidg->write_queue, wait); + poll_wait(file, &hidg->get_queue, wait); + poll_wait(file, &hidg->get_id_queue, wait); if (WRITE_COND) ret |= EPOLLOUT | EPOLLWRNORM; @@ -543,12 +739,16 @@ static __poll_t f_hidg_poll(struct file *file, poll_table *wait) ret |= EPOLLIN | EPOLLRDNORM; } + if (GET_REPORT_COND) + ret |= EPOLLPRI; + return ret; } #undef WRITE_COND #undef READ_COND_SSREPORT #undef READ_COND_INTOUT +#undef GET_REPORT_COND static int f_hidg_release(struct inode *inode, struct file *fd) { @@ -641,6 +841,10 @@ static void hidg_ssreport_complete(struct usb_ep *ep, struct usb_request *req) wake_up(&hidg->read_queue); } +static void hidg_get_report_complete(struct usb_ep *ep, struct usb_request *req) +{ +} + static int hidg_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl) { @@ -649,6 +853,7 @@ static int hidg_setup(struct usb_function *f, struct usb_request *req = cdev->req; int status = 0; __u16 value, length; + unsigned long flags; value = __le16_to_cpu(ctrl->wValue); length = __le16_to_cpu(ctrl->wLength); @@ -660,14 +865,20 @@ static int hidg_setup(struct usb_function *f, switch ((ctrl->bRequestType << 8) | ctrl->bRequest) { case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8 | HID_REQ_GET_REPORT): - VDBG(cdev, "get_report\n"); + VDBG(cdev, "get_report | wLength=%d\n", ctrl->wLength); - /* send an empty report */ - length = min_t(unsigned, length, hidg->report_length); - memset(req->buf, 0x0, length); + /* + * Update GET_REPORT ID so that an ioctl can be used to determine what + * GET_REPORT the request was actually for. + */ + spin_lock_irqsave(&hidg->get_report_spinlock, flags); + hidg->get_report_req_report_id = value & 0xff; + hidg->get_report_req_report_length = length; + spin_unlock_irqrestore(&hidg->get_report_spinlock, flags); - goto respond; - break; + queue_work(hidg->workqueue, &hidg->work); + + return status; case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8 | HID_REQ_GET_PROTOCOL): @@ -793,6 +1004,14 @@ static void hidg_disable(struct usb_function *f) spin_unlock_irqrestore(&hidg->read_spinlock, flags); } + spin_lock_irqsave(&hidg->get_report_spinlock, flags); + if (!hidg->get_report_returned) { + usb_ep_free_request(f->config->cdev->gadget->ep0, hidg->get_req); + hidg->get_req = NULL; + hidg->get_report_returned = true; + } + spin_unlock_irqrestore(&hidg->get_report_spinlock, flags); + spin_lock_irqsave(&hidg->write_spinlock, flags); if (!hidg->write_pending) { free_ep_req(hidg->in_ep, hidg->req); @@ -902,6 +1121,14 @@ fail: return status; } +#ifdef CONFIG_COMPAT +static long f_hidg_compat_ioctl(struct file *file, unsigned int code, + unsigned long value) +{ + return f_hidg_ioctl(file, code, value); +} +#endif + static const struct file_operations f_hidg_fops = { .owner = THIS_MODULE, .open = f_hidg_open, @@ -909,6 +1136,10 @@ static const struct file_operations f_hidg_fops = { .write = f_hidg_write, .read = f_hidg_read, .poll = f_hidg_poll, + .unlocked_ioctl = f_hidg_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = f_hidg_compat_ioctl, +#endif .llseek = noop_llseek, }; @@ -919,6 +1150,15 @@ static int hidg_bind(struct usb_configuration *c, struct usb_function *f) struct usb_string *us; int status; + hidg->get_req = usb_ep_alloc_request(c->cdev->gadget->ep0, GFP_ATOMIC); + if (!hidg->get_req) + return -ENOMEM; + + hidg->get_req->zero = 0; + hidg->get_req->complete = hidg_get_report_complete; + hidg->get_req->context = hidg; + hidg->get_report_returned = true; + /* maybe allocate device-global string IDs, and patch descriptors */ us = usb_gstrings_attach(c->cdev, ct_func_strings, ARRAY_SIZE(ct_func_string_defs)); @@ -1004,9 +1244,24 @@ static int hidg_bind(struct usb_configuration *c, struct usb_function *f) hidg->write_pending = 1; hidg->req = NULL; spin_lock_init(&hidg->read_spinlock); + spin_lock_init(&hidg->get_report_spinlock); init_waitqueue_head(&hidg->write_queue); init_waitqueue_head(&hidg->read_queue); + init_waitqueue_head(&hidg->get_queue); + init_waitqueue_head(&hidg->get_id_queue); INIT_LIST_HEAD(&hidg->completed_out_req); + INIT_LIST_HEAD(&hidg->report_list); + + INIT_WORK(&hidg->work, get_report_workqueue_handler); + hidg->workqueue = alloc_workqueue("report_work", + WQ_FREEZABLE | + WQ_MEM_RECLAIM, + 1); + + if (!hidg->workqueue) { + status = -ENOMEM; + goto fail; + } /* create char device */ cdev_init(&hidg->cdev, &f_hidg_fops); @@ -1016,12 +1271,16 @@ static int hidg_bind(struct usb_configuration *c, struct usb_function *f) return 0; fail_free_descs: + destroy_workqueue(hidg->workqueue); usb_free_all_descriptors(f); fail: ERROR(f->config->cdev, "hidg_bind FAILED\n"); if (hidg->req != NULL) free_ep_req(hidg->in_ep, hidg->req); + usb_ep_free_request(c->cdev->gadget->ep0, hidg->get_req); + hidg->get_req = NULL; + return status; } @@ -1256,7 +1515,7 @@ static void hidg_unbind(struct usb_configuration *c, struct usb_function *f) struct f_hidg *hidg = func_to_hidg(f); cdev_device_del(&hidg->cdev, &hidg->dev); - + destroy_workqueue(hidg->workqueue); usb_free_all_descriptors(f); } diff --git a/include/uapi/linux/usb/g_hid.h b/include/uapi/linux/usb/g_hid.h new file mode 100644 index 000000000000..b965092db476 --- /dev/null +++ b/include/uapi/linux/usb/g_hid.h @@ -0,0 +1,40 @@ +/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */ + +#ifndef __UAPI_LINUX_USB_G_HID_H +#define __UAPI_LINUX_USB_G_HID_H + +#include <linux/types.h> + +/* Maximum HID report length for High-Speed USB (i.e. USB 2.0) */ +#define MAX_REPORT_LENGTH 64 + +/** + * struct usb_hidg_report - response to GET_REPORT + * @report_id: report ID that this is a response for + * @userspace_req: + * !0 this report is used for any pending GET_REPORT request + * but wait on userspace to issue a new report on future requests + * 0 this report is to be used for any future GET_REPORT requests + * @length: length of the report response + * @data: report response + * @padding: padding for 32/64 bit compatibility + * + * Structure used by GADGET_HID_WRITE_GET_REPORT ioctl on /dev/hidg*. + */ +struct usb_hidg_report { + __u8 report_id; + __u8 userspace_req; + __u16 length; + __u8 data[MAX_REPORT_LENGTH]; + __u8 padding[4]; +}; + +/* The 'g' code is used by gadgetfs and hid gadget ioctl requests. + * Don't add any colliding codes to either driver, and keep + * them in unique ranges. + */ + +#define GADGET_HID_READ_GET_REPORT_ID _IOR('g', 0x41, __u8) +#define GADGET_HID_WRITE_GET_REPORT _IOW('g', 0x42, struct usb_hidg_report) + +#endif /* __UAPI_LINUX_USB_G_HID_H */ diff --git a/include/uapi/linux/usb/gadgetfs.h b/include/uapi/linux/usb/gadgetfs.h index 835473910a49..9754822b2a40 100644 --- a/include/uapi/linux/usb/gadgetfs.h +++ b/include/uapi/linux/usb/gadgetfs.h @@ -62,7 +62,7 @@ struct usb_gadgetfs_event { }; -/* The 'g' code is also used by printer gadget ioctl requests. +/* The 'g' code is also used by printer and hid gadget ioctl requests. * Don't add any colliding codes to either driver, and keep * them in unique ranges (size 0x20 for now). */ |