From nobody Sun Apr 12 05:50:50 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 112CEC00144 for ; Mon, 1 Aug 2022 12:45:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232527AbiHAMpH (ORCPT ); Mon, 1 Aug 2022 08:45:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44152 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234879AbiHAMoX (ORCPT ); Mon, 1 Aug 2022 08:44:23 -0400 Received: from mail-pl1-x631.google.com (mail-pl1-x631.google.com [IPv6:2607:f8b0:4864:20::631]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 25C3DB7F1 for ; Mon, 1 Aug 2022 05:30:26 -0700 (PDT) Received: by mail-pl1-x631.google.com with SMTP id y15so10288882plp.10 for ; Mon, 01 Aug 2022 05:30:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amarulasolutions.com; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc; bh=7o91HERS/4hsq8FU5w5VEekCf+JsdrZ+o3ocEJkypqs=; b=GgGkvY84gXaQc+2I8pszEPJbyM4Ph2Rk/lwEbg3egwKN3HIfpLN7OyZ/i/YDfcPl6Z fQxZDJSpfpdSaPa7fEpmor+CT3V24bppJn4iLeVXMX8nERJO2m8I2baX36bag5fTkgjL G3bcGRgypZk7tIy9W8QbrcMpilAp8Qrf712Cg= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc; bh=7o91HERS/4hsq8FU5w5VEekCf+JsdrZ+o3ocEJkypqs=; b=eI4tcwGHa84d9XrBNMaLaQFR2XyF0b7lAQfEuCUH3CSD1Bs5Z1yNlzf3YmFLMg5HM6 YtLk7c/fgXcsox71Pi6OqL+gYD11NAfVlGgWJTRiPEAQRRIOYT5zE4xg+Tn5symh2obl N12LbOS4xsmaIM21+yw/wlNrWsbTN/kkjbx5NOat91NGxGiLOOEAs/j0SYO/lb5NoZCJ lns3PXtkNgAYkF2+troliBiYG4gwI9SAprjznWg0XDAlKFioFTipJAR9ZWHFLpO8aq3o +hL39Jv/1Temlbrz9RuME+pLqztfPMighq/PeeCGOzSc7RSd0dfIhgPQlPwwDWO3KY9Q hEbg== X-Gm-Message-State: ACgBeo30+7m8qqeBTIamzMYxnX41D/uVQaHvLA+xGnfJd5KhLTpIyT4P 9OzPlYlhl3xl20/iMalL8tuZUA== X-Google-Smtp-Source: AA6agR7q2oQCzE2Dj6UzhPjXnAKFHMShOervH2Te1LPRNyiHIDscNEEurFTMdVRTsB9p2/ykkVHQJQ== X-Received: by 2002:a17:90b:3c1:b0:1f3:17bd:2e5b with SMTP id go1-20020a17090b03c100b001f317bd2e5bmr19069861pjb.107.1659357025540; Mon, 01 Aug 2022 05:30:25 -0700 (PDT) Received: from localhost.localdomain ([183.83.136.224]) by smtp.gmail.com with ESMTPSA id a14-20020a1709027e4e00b0015e8d4eb219sm3473230pln.99.2022.08.01.05.30.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 01 Aug 2022 05:30:25 -0700 (PDT) From: Suniel Mahesh To: Felipe Balbi , Greg Kroah-Hartman , Michael Trimarchi , Jagan Teki Cc: linux-kernel@vger.kernel.org, linux-amarula@amarulasolutions.com, USB list Subject: [RFC 1/2] usb: gadget: f_hid: Extend functionality for GET_REPORT mode Date: Mon, 1 Aug 2022 18:00:09 +0530 Message-Id: <20220801123010.2984864-2-sunil@amarulasolutions.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220801123010.2984864-1-sunil@amarulasolutions.com> References: <20220801123010.2984864-1-sunil@amarulasolutions.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The current kernel implementation for GET_REPORT is that the kernel sends back a zero filled report (of length =3D=3D report_length), when the Host request's a particular report from the device/gadget. This changeset extends functionality for GET_REPORT by sending a particular report based on report type and report number. corresponding ioctl is also implemented. Signed-off-by: Suniel Mahesh Signed-off-by: Michael Trimarchi --- drivers/usb/gadget/function/f_hid.c | 166 ++++++++++++++++++++++++++- include/{ =3D> uapi}/linux/usb/g_hid.h | 10 ++ 2 files changed, 174 insertions(+), 2 deletions(-) rename include/{ =3D> uapi}/linux/usb/g_hid.h (72%) diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/funct= ion/f_hid.c index ca0a7d9eaa34..70787c73caf9 100644 --- a/drivers/usb/gadget/function/f_hid.c +++ b/drivers/usb/gadget/function/f_hid.c @@ -16,6 +16,7 @@ #include #include #include +#include =20 #include "u_f.h" #include "u_hid.h" @@ -27,6 +28,11 @@ static struct class *hidg_class; static DEFINE_IDA(hidg_ida); static DEFINE_MUTEX(hidg_ida_lock); /* protects access to hidg_ida */ =20 +struct report_entry { + struct uhid_set_report_req report_data; + struct list_head node; +}; + /*------------------------------------------------------------------------= -*/ /* HID gadget struct = */ =20 @@ -71,6 +77,10 @@ struct f_hidg { wait_queue_head_t write_queue; struct usb_request *req; =20 + /* hid report list */ + spinlock_t report_spinlock; + struct list_head report_list; + int minor; struct cdev cdev; struct usb_function func; @@ -553,6 +563,136 @@ static int f_hidg_open(struct inode *inode, struct fi= le *fd) return 0; } =20 +static bool f_hidg_param_valid(struct report_entry *entry) +{ + + if (entry->report_data.size > UHID_DATA_MAX) + return false; + + switch (entry->report_data.rtype) { + case UHID_FEATURE_REPORT: + case UHID_OUTPUT_REPORT: + case UHID_INPUT_REPORT: + return true; + default: + break; + } + + return false; +} + +static struct report_entry *f_hidg_search_for_report(struct f_hidg *hidg, = u8 rnum, u8 rtype) +{ + struct list_head *ptr; + struct report_entry *entry; + + list_for_each(ptr, &hidg->report_list) { + entry =3D list_entry(ptr, struct report_entry, node); + if (entry->report_data.rnum =3D=3D rnum && + entry->report_data.rtype =3D=3D rtype) { + return entry; + } + } + + return NULL; +} + +static long f_hidg_ioctl(struct file *file, unsigned int cmd, unsigned lon= g arg) +{ + struct f_hidg *hidg =3D file->private_data; + struct report_entry *entry; + struct report_entry *ptr; + unsigned long flags; + struct uhid_get_report_req report; + u16 size; + + switch (cmd) { + case GADGET_ADD_REPORT_STATUS: + entry =3D kmalloc(sizeof(*entry), GFP_KERNEL); + if (!entry) + return -ENOMEM; + + if (copy_from_user(&entry->report_data, (struct uhid_set_report_req *)ar= g, + sizeof(struct uhid_set_report_req))) { + kfree(entry); + return -EFAULT; + } + + if (f_hidg_param_valid(entry) =3D=3D false) { + kfree(entry); + return -EINVAL; + } + + spin_lock_irqsave(&hidg->report_spinlock, flags); + ptr =3D f_hidg_search_for_report(hidg, entry->report_data.rnum, + entry->report_data.rtype); + if (ptr) { + spin_unlock_irqrestore(&hidg->report_spinlock, flags); + kfree(ptr); + return -EEXIST; + } + list_add_tail(&entry->node, &hidg->report_list); + spin_unlock_irqrestore(&hidg->report_spinlock, flags); + break; + case GADGET_REMOVE_REPORT_STATUS: + spin_lock_irqsave(&hidg->report_spinlock, flags); + if (list_empty(&hidg->report_list)) { + spin_unlock_irqrestore(&hidg->report_spinlock, flags); + return -ENODATA; + } + spin_unlock_irqrestore(&hidg->report_spinlock, flags); + + if (copy_from_user(&report, (struct uhid_get_report_req *)arg, sizeof(re= port))) + return -EFAULT; + + spin_lock_irqsave(&hidg->report_spinlock, flags); + + ptr =3D f_hidg_search_for_report(hidg, report.rnum, report.rtype); + if (ptr) { + list_del(&ptr->node); + } else { + spin_unlock_irqrestore(&hidg->report_spinlock, flags); + return -ENODATA; + } + spin_unlock_irqrestore(&hidg->report_spinlock, flags); + kfree(ptr); + break; + case GADGET_UPDATE_REPORT_STATUS: + spin_lock_irqsave(&hidg->report_spinlock, flags); + if (list_empty(&hidg->report_list)) { + spin_unlock_irqrestore(&hidg->report_spinlock, flags); + return -ENODATA; + } + spin_unlock_irqrestore(&hidg->report_spinlock, flags); + + if (copy_from_user(&report, (struct uhid_get_report_req *)arg, sizeof(re= port))) + return -EFAULT; + + if (copy_from_user(&size, (void __user *)(arg + sizeof(report)), sizeof(= size))) + return -EFAULT; + + if (size > UHID_DATA_MAX) + return -EINVAL; + + spin_lock_irqsave(&hidg->report_spinlock, flags); + + ptr =3D f_hidg_search_for_report(hidg, report.rnum, report.rtype); + if (!ptr) { + spin_unlock_irqrestore(&hidg->report_spinlock, flags); + return -ENODATA; + } + + if (copy_from_user(&ptr->report_data, (struct uhid_set_report_req *)arg, + sizeof(struct uhid_set_report_req))) { + spin_unlock_irqrestore(&hidg->report_spinlock, flags); + return -EFAULT; + } + spin_unlock_irqrestore(&hidg->report_spinlock, flags); + break; + } + return 0; +} + /*------------------------------------------------------------------------= -*/ /* usb_function = */ =20 @@ -634,6 +774,8 @@ static int hidg_setup(struct usb_function *f, struct f_hidg *hidg =3D func_to_hidg(f); struct usb_composite_dev *cdev =3D f->config->cdev; struct usb_request *req =3D cdev->req; + struct report_entry *entry; + unsigned long flags; int status =3D 0; __u16 value, length; =20 @@ -649,9 +791,25 @@ static int hidg_setup(struct usb_function *f, | HID_REQ_GET_REPORT): VDBG(cdev, "get_report\n"); =20 - /* send an empty report */ length =3D min_t(unsigned, length, hidg->report_length); - memset(req->buf, 0x0, length); + spin_lock_irqsave(&hidg->report_spinlock, flags); + if (list_empty(&hidg->report_list)) { + spin_unlock_irqrestore(&hidg->report_spinlock, flags); + memset(req->buf, 0x0, length); + goto respond; + } + + entry =3D f_hidg_search_for_report(hidg, value & 0xf, + value >> 8); + + /* send a report */ + if (entry) { + length =3D min_t(unsigned, length, entry->report_data.size); + memcpy(req->buf, entry->report_data.data, length); + } else { + memset(req->buf, 0x0, length); + } + spin_unlock_irqrestore(&hidg->report_spinlock, flags); =20 goto respond; break; @@ -893,6 +1051,7 @@ static const struct file_operations f_hidg_fops =3D { .owner =3D THIS_MODULE, .open =3D f_hidg_open, .release =3D f_hidg_release, + .unlocked_ioctl =3D f_hidg_ioctl, .write =3D f_hidg_write, .read =3D f_hidg_read, .poll =3D f_hidg_poll, @@ -997,6 +1156,9 @@ static int hidg_bind(struct usb_configuration *c, stru= ct usb_function *f) init_waitqueue_head(&hidg->read_queue); INIT_LIST_HEAD(&hidg->completed_out_req); =20 + spin_lock_init(&hidg->report_spinlock); + INIT_LIST_HEAD(&hidg->report_list); + /* create char device */ cdev_init(&hidg->cdev, &f_hidg_fops); dev =3D MKDEV(major, hidg->minor); diff --git a/include/linux/usb/g_hid.h b/include/uapi/linux/usb/g_hid.h similarity index 72% rename from include/linux/usb/g_hid.h rename to include/uapi/linux/usb/g_hid.h index 7581e488c237..ba3e47f076bb 100644 --- a/include/linux/usb/g_hid.h +++ b/include/uapi/linux/usb/g_hid.h @@ -22,6 +22,8 @@ #ifndef __LINUX_USB_G_HID_H #define __LINUX_USB_G_HID_H =20 +#include + struct hidg_func_descriptor { unsigned char subclass; unsigned char protocol; @@ -30,4 +32,12 @@ struct hidg_func_descriptor { unsigned char report_desc[]; }; =20 +/* The 'g' code is also used by gadgetfs and printer ioctl requests. + * Don't add any colliding codes to either driver, and keep + * them in unique ranges (size 0x40 for now). + */ +#define GADGET_ADD_REPORT_STATUS _IOWR('g', 0x41, struct uhid_set_report_r= eq) +#define GADGET_REMOVE_REPORT_STATUS _IOWR('g', 0x42, struct uhid_get_repor= t_req) +#define GADGET_UPDATE_REPORT_STATUS _IOWR('g', 0x43, struct uhid_set_repor= t_req) + #endif /* __LINUX_USB_G_HID_H */ --=20 2.25.1