diff options
| -rw-r--r-- | Documentation/ABI/testing/configfs-usb-gadget-hid | 11 | ||||
| -rw-r--r-- | Documentation/usb/gadget_hid.txt | 7 | ||||
| -rw-r--r-- | drivers/usb/gadget/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/usb/gadget/function/f_hid.c | 144 | ||||
| -rw-r--r-- | drivers/usb/gadget/function/u_hid.h | 7 |
5 files changed, 178 insertions, 1 deletions
diff --git a/Documentation/ABI/testing/configfs-usb-gadget-hid b/Documentation/ABI/testing/configfs-usb-gadget-hid new file mode 100644 index 000000000000..f12e00e6baa3 --- /dev/null +++ b/Documentation/ABI/testing/configfs-usb-gadget-hid @@ -0,0 +1,11 @@ +What: /config/usb-gadget/gadget/functions/hid.name +Date: Nov 2014 +KernelVersion: 3.19 +Description: + The attributes: + + protocol - HID protocol to use + report_desc - blob corresponding to HID report descriptors + except the data passed through /dev/hidg<N> + report_length - HID report length + subclass - HID device subclass to use diff --git a/Documentation/usb/gadget_hid.txt b/Documentation/usb/gadget_hid.txt index 12696c2e43fb..7a0fb8e16e27 100644 --- a/Documentation/usb/gadget_hid.txt +++ b/Documentation/usb/gadget_hid.txt @@ -74,6 +74,13 @@ static struct platform_device my_hid = { You can add as many HID functions as you want, only limited by the amount of interrupt endpoints your gadget driver supports. +Configuration with configfs + + Instead of adding fake platform devices and drivers in order to pass + some data to the kernel, if HID is a part of a gadget composed with + configfs the hidg_func_descriptor.report_desc is passed to the kernel + by writing the appropriate stream of bytes to a configfs attribute. + Send and receive HID reports HID reports can be sent/received using read/write on the diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig index ea2d7706db6c..747ef53bda14 100644 --- a/drivers/usb/gadget/Kconfig +++ b/drivers/usb/gadget/Kconfig @@ -413,6 +413,16 @@ config USB_CONFIGFS_F_MIDI connections can then be made on the gadget system, using ALSA's aconnect utility etc. +config USB_CONFIGFS_F_HID + boolean "HID function" + depends on USB_CONFIGFS + select USB_F_HID + help + The HID function driver provides generic emulation of USB + Human Interface Devices (HID). + + For more information, see Documentation/usb/gadget_hid.txt. + source "drivers/usb/gadget/legacy/Kconfig" endchoice diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c index dfdb4327ef3e..56ca3fc81555 100644 --- a/drivers/usb/gadget/function/f_hid.c +++ b/drivers/usb/gadget/function/f_hid.c @@ -690,6 +690,136 @@ static inline int hidg_get_minor(void) return ret; } +static inline struct f_hid_opts *to_f_hid_opts(struct config_item *item) +{ + return container_of(to_config_group(item), struct f_hid_opts, + func_inst.group); +} + +CONFIGFS_ATTR_STRUCT(f_hid_opts); +CONFIGFS_ATTR_OPS(f_hid_opts); + +static void hid_attr_release(struct config_item *item) +{ + struct f_hid_opts *opts = to_f_hid_opts(item); + + usb_put_function_instance(&opts->func_inst); +} + +static struct configfs_item_operations hidg_item_ops = { + .release = hid_attr_release, + .show_attribute = f_hid_opts_attr_show, + .store_attribute = f_hid_opts_attr_store, +}; + +#define F_HID_OPT(name, prec, limit) \ +static ssize_t f_hid_opts_##name##_show(struct f_hid_opts *opts, char *page)\ +{ \ + int result; \ + \ + mutex_lock(&opts->lock); \ + result = sprintf(page, "%d\n", opts->name); \ + mutex_unlock(&opts->lock); \ + \ + return result; \ +} \ + \ +static ssize_t f_hid_opts_##name##_store(struct f_hid_opts *opts, \ + const char *page, size_t len) \ +{ \ + int ret; \ + u##prec num; \ + \ + mutex_lock(&opts->lock); \ + if (opts->refcnt) { \ + ret = -EBUSY; \ + goto end; \ + } \ + \ + ret = kstrtou##prec(page, 0, &num); \ + if (ret) \ + goto end; \ + \ + if (num > limit) { \ + ret = -EINVAL; \ + goto end; \ + } \ + opts->name = num; \ + ret = len; \ + \ +end: \ + mutex_unlock(&opts->lock); \ + return ret; \ +} \ + \ +static struct f_hid_opts_attribute f_hid_opts_##name = \ + __CONFIGFS_ATTR(name, S_IRUGO | S_IWUSR, f_hid_opts_##name##_show,\ + f_hid_opts_##name##_store) + +F_HID_OPT(subclass, 8, 255); +F_HID_OPT(protocol, 8, 255); +F_HID_OPT(report_length, 16, 65536); + +static ssize_t f_hid_opts_report_desc_show(struct f_hid_opts *opts, char *page) +{ + int result; + + mutex_lock(&opts->lock); + result = opts->report_desc_length; + memcpy(page, opts->report_desc, opts->report_desc_length); + mutex_unlock(&opts->lock); + + return result; +} + +static ssize_t f_hid_opts_report_desc_store(struct f_hid_opts *opts, + const char *page, size_t len) +{ + int ret = -EBUSY; + char *d; + + mutex_lock(&opts->lock); + + if (opts->refcnt) + goto end; + if (len > PAGE_SIZE) { + ret = -ENOSPC; + goto end; + } + d = kmemdup(page, len, GFP_KERNEL); + if (!d) { + ret = -ENOMEM; + goto end; + } + kfree(opts->report_desc); + opts->report_desc = d; + opts->report_desc_length = len; + opts->report_desc_alloc = true; + ret = len; +end: + mutex_unlock(&opts->lock); + return ret; +} + +static struct f_hid_opts_attribute f_hid_opts_report_desc = + __CONFIGFS_ATTR(report_desc, S_IRUGO | S_IWUSR, + f_hid_opts_report_desc_show, + f_hid_opts_report_desc_store); + +static struct configfs_attribute *hid_attrs[] = { + &f_hid_opts_subclass.attr, + &f_hid_opts_protocol.attr, + &f_hid_opts_report_length.attr, + &f_hid_opts_report_desc.attr, + NULL, +}; + +static struct config_item_type hid_func_type = { + .ct_item_ops = &hidg_item_ops, + .ct_attrs = hid_attrs, + .ct_owner = THIS_MODULE, +}; + static inline void hidg_put_minor(int minor) { ida_simple_remove(&hidg_ida, minor); @@ -724,7 +854,7 @@ static struct usb_function_instance *hidg_alloc_inst(void) opts = kzalloc(sizeof(*opts), GFP_KERNEL); if (!opts) return ERR_PTR(-ENOMEM); - + mutex_init(&opts->lock); opts->func_inst.free_func_inst = hidg_free_inst; ret = &opts->func_inst; @@ -746,6 +876,7 @@ static struct usb_function_instance *hidg_alloc_inst(void) if (idr_is_empty(&hidg_ida.idr)) ghid_cleanup(); } + config_group_init_type_name(&opts->func_inst.group, "", &hid_func_type); unlock: mutex_unlock(&hidg_ida_lock); @@ -755,10 +886,15 @@ unlock: static void hidg_free(struct usb_function *f) { struct f_hidg *hidg; + struct f_hid_opts *opts; hidg = func_to_hidg(f); + opts = container_of(f->fi, struct f_hid_opts, func_inst); kfree(hidg->report_desc); kfree(hidg); + mutex_lock(&opts->lock); + --opts->refcnt; + mutex_unlock(&opts->lock); } static void hidg_unbind(struct usb_configuration *c, struct usb_function *f) @@ -789,6 +925,9 @@ struct usb_function *hidg_alloc(struct usb_function_instance *fi) opts = container_of(fi, struct f_hid_opts, func_inst); + mutex_lock(&opts->lock); + ++opts->refcnt; + hidg->minor = opts->minor; hidg->bInterfaceSubClass = opts->subclass; hidg->bInterfaceProtocol = opts->protocol; @@ -800,10 +939,13 @@ struct usb_function *hidg_alloc(struct usb_function_instance *fi) GFP_KERNEL); if (!hidg->report_desc) { kfree(hidg); + mutex_unlock(&opts->lock); return ERR_PTR(-ENOMEM); } } + mutex_unlock(&opts->lock); + hidg->func.name = "hid"; hidg->func.bind = hidg_bind; hidg->func.unbind = hidg_unbind; diff --git a/drivers/usb/gadget/function/u_hid.h b/drivers/usb/gadget/function/u_hid.h index 3edfc9567ab7..aaa0e368a159 100644 --- a/drivers/usb/gadget/function/u_hid.h +++ b/drivers/usb/gadget/function/u_hid.h @@ -27,6 +27,13 @@ struct f_hid_opts { unsigned short report_desc_length; unsigned char *report_desc; bool report_desc_alloc; + + /* + * Protect the data form concurrent access by read/write + * and create symlink/remove symlink. + */ + struct mutex lock; + int refcnt; }; int ghid_setup(struct usb_gadget *g, int count); |