From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934759AbcA0SPZ (ORCPT ); Wed, 27 Jan 2016 13:15:25 -0500 Received: from mail-wm0-f66.google.com ([74.125.82.66]:34463 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934130AbcA0SPU (ORCPT ); Wed, 27 Jan 2016 13:15:20 -0500 Date: Wed, 27 Jan 2016 19:15:15 +0100 From: Dave Penkler To: gregkh@linuxfoundation.org Cc: peter.chen@freescale.com, teuniz@gmail.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v7 2/5] Add support for USBTMC USB488 SRQ notification with fasync Message-ID: <20160127181515.GB4658@slacky> References: <20160127175742.GA4650@slacky> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160127175742.GA4650@slacky> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Background: By configuring an instrument's event status register various conditions can be reported via an SRQ notification. This complements the synchronous polling approach using the READ_STATUS_BYTE ioctl with an asynchronous notification. Signed-off-by: Dave Penkler --- drivers/usb/class/usbtmc.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c index c2eb6fe..d77da2f 100644 --- a/drivers/usb/class/usbtmc.c +++ b/drivers/usb/class/usbtmc.c @@ -99,6 +99,7 @@ struct usbtmc_device_data { int iin_interval; struct urb *iin_urb; u16 iin_wMaxPacketSize; + atomic_t srq_asserted; u8 rigol_quirk; @@ -113,6 +114,7 @@ struct usbtmc_device_data { struct kref kref; struct mutex io_mutex; /* only one i/o function running at a time */ wait_queue_head_t waitq; + struct fasync_struct *fasync; }; #define to_usbtmc_data(d) container_of(d, struct usbtmc_device_data, kref) @@ -405,6 +407,9 @@ static int usbtmc488_ioctl_read_stb(struct usbtmc_device_data *data, atomic_set(&data->iin_data_valid, 0); + /* must issue read_stb before using poll or select */ + atomic_set(&data->srq_asserted, 0); + rv = usb_control_msg(data->usb_dev, usb_rcvctrlpipe(data->usb_dev, 0), USBTMC488_REQUEST_READ_STATUS_BYTE, @@ -1172,6 +1177,13 @@ skip_io_on_zombie: return retval; } +static int usbtmc_fasync(int fd, struct file *file, int on) +{ + struct usbtmc_device_data *data = file->private_data; + + return fasync_helper(fd, file, on, &data->fasync); +} + static const struct file_operations fops = { .owner = THIS_MODULE, .read = usbtmc_read, @@ -1179,6 +1191,7 @@ static const struct file_operations fops = { .open = usbtmc_open, .release = usbtmc_release, .unlocked_ioctl = usbtmc_ioctl, + .fasync = usbtmc_fasync, .llseek = default_llseek, }; @@ -1208,6 +1221,16 @@ static void usbtmc_interrupt(struct urb *urb) wake_up_interruptible(&data->waitq); goto exit; } + /* check for SRQ notification */ + if (data->iin_buffer[0] == 0x81) { + if (data->fasync) + kill_fasync(&data->fasync, + SIGIO, POLL_IN); + + atomic_set(&data->srq_asserted, 1); + wake_up_interruptible(&data->waitq); + goto exit; + } dev_warn(dev, "invalid notification: %x\n", data->iin_buffer[0]); break; case -EOVERFLOW: @@ -1263,6 +1286,7 @@ static int usbtmc_probe(struct usb_interface *intf, mutex_init(&data->io_mutex); init_waitqueue_head(&data->waitq); atomic_set(&data->iin_data_valid, 0); + atomic_set(&data->srq_asserted, 0); data->zombie = 0; /* Determine if it is a Rigol or not */ -- 2.6.3