Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753215AbdFLR21 (ORCPT ); Mon, 12 Jun 2017 13:28:27 -0400 Received: from mail-wr0-f193.google.com ([209.85.128.193]:33760 "EHLO mail-wr0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753200AbdFLR1J (ORCPT ); Mon, 12 Jun 2017 13:27:09 -0400 From: Tal Shorer To: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, gregkh@linuxfoundation.org, balbi@kernel.org, corbet@lwn.net Cc: Tal Shorer Subject: [PATCH 7/8] usb: gadget: f_acm: notify the user on SetLineCoding Date: Mon, 12 Jun 2017 20:26:14 +0300 Message-Id: <1497288375-3559-8-git-send-email-tal.shorer@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1497288375-3559-1-git-send-email-tal.shorer@gmail.com> References: <1497288375-3559-1-git-send-email-tal.shorer@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3434 Lines: 106 Notify the user with a POLLPRI event when the host issues a SetLineCoding request so that they can act upon it, for example by configuring the line coding on a real serial port. The event is cleared when the user reads the line coding using USB_F_ACM_GET_LINE_CODING ioctl() Signed-off-by: Tal Shorer --- drivers/usb/gadget/function/f_acm.c | 38 ++++++++++++++++++++++++++----------- 1 file changed, 27 insertions(+), 11 deletions(-) diff --git a/drivers/usb/gadget/function/f_acm.c b/drivers/usb/gadget/function/f_acm.c index 5feea7c..0983999 100644 --- a/drivers/usb/gadget/function/f_acm.c +++ b/drivers/usb/gadget/function/f_acm.c @@ -58,6 +58,9 @@ struct f_acm { struct usb_request *notify_req; struct usb_cdc_line_coding port_line_coding; /* 8-N-1 etc */ + /* we have a SetLineCoding request that the user haven't read yet */ + bool set_line_coding_pending; + wait_queue_head_t set_line_coding_waitq; /* SetControlLineState request -- CDC 1.1 section 6.2.14 (INPUT) */ u16 port_handshake_bits; @@ -326,23 +329,19 @@ static void acm_complete_set_line_coding(struct usb_ep *ep, } else { struct usb_cdc_line_coding *value = req->buf; - /* REVISIT: we currently just remember this data. - * If we change that, - * (a) update whatever hardware needs updating, - * (b) worry about locking. This is information on - * the order of 9600-8-N-1 ... most of which means - * nothing unless we control a real RS232 line. - */ dev_dbg(&cdev->gadget->dev, "acm ttyGS%d set_line_coding: %d %d %d %d\n", acm->port_num, le32_to_cpu(value->dwDTERate), value->bCharFormat, value->bParityType, value->bDataBits); if (value->bCharFormat > 2 || value->bParityType > 4 || - value->bDataBits < 5 || value->bDataBits > 8) + value->bDataBits < 5 || value->bDataBits > 8) { usb_ep_set_halt(ep); - else + } else { acm->port_line_coding = *value; + acm->set_line_coding_pending = true; + wake_up_interruptible(&acm->set_line_coding_waitq); + } } } @@ -598,6 +597,19 @@ static void acm_disconnect(struct gserial *port) acm_notify_serial_state(acm); } +static unsigned int acm_poll(struct gserial *port, struct file *file, + poll_table *wait) +{ + unsigned int mask = 0; + struct f_acm *acm = port_to_acm(port); + + poll_wait(file, &acm->set_line_coding_waitq, wait); + if (acm->set_line_coding_pending) + mask |= POLLPRI; + return mask; +} + + static int acm_send_break(struct gserial *port, int duration) { struct f_acm *acm = port_to_acm(port); @@ -620,10 +632,12 @@ static int acm_ioctl(struct gserial *port, unsigned int cmd, unsigned long arg) switch (cmd) { case USB_F_ACM_GET_LINE_CODING: if (copy_to_user((__user void *)arg, &acm->port_line_coding, - sizeof(acm->port_line_coding))) + sizeof(acm->port_line_coding))) { ret = -EFAULT; - else + } else { ret = 0; + acm->set_line_coding_pending = false; + } break; } return ret; @@ -763,11 +777,13 @@ static struct usb_function *acm_alloc_func(struct usb_function_instance *fi) return ERR_PTR(-ENOMEM); spin_lock_init(&acm->lock); + init_waitqueue_head(&acm->set_line_coding_waitq); acm->port.connect = acm_connect; acm->port.disconnect = acm_disconnect; acm->port.send_break = acm_send_break; acm->port.ioctl = acm_ioctl; + acm->port.poll = acm_poll; acm->port.func.name = "acm"; acm->port.func.strings = acm_strings; -- 2.7.4