From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3682FC2D0BF for ; Tue, 17 Dec 2019 16:58:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1223821D7D for ; Tue, 17 Dec 2019 16:58:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727896AbfLQQ6h (ORCPT ); Tue, 17 Dec 2019 11:58:37 -0500 Received: from metis.ext.pengutronix.de ([85.220.165.71]:51111 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727417AbfLQQ6g (ORCPT ); Tue, 17 Dec 2019 11:58:36 -0500 Received: from pty.hi.pengutronix.de ([2001:67c:670:100:1d::c5]) by metis.ext.pengutronix.de with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1ihGAx-0003dM-Im; Tue, 17 Dec 2019 17:58:23 +0100 Received: from ukl by pty.hi.pengutronix.de with local (Exim 4.89) (envelope-from ) id 1ihGAw-000406-JL; Tue, 17 Dec 2019 17:58:22 +0100 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= To: Jacek Anaszewski , Pavel Machek , Dan Murphy , Greg Kroah-Hartman , Jiri Slaby Cc: kernel@pengutronix.de, linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org, linux-serial@vger.kernel.org Subject: [PATCH v4 3/3] leds: trigger: implement a tty trigger Date: Tue, 17 Dec 2019 17:58:16 +0100 Message-Id: <20191217165816.19324-4-u.kleine-koenig@pengutronix.de> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191217165816.19324-1-u.kleine-koenig@pengutronix.de> References: <20191217165816.19324-1-u.kleine-koenig@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c5 X-SA-Exim-Mail-From: ukl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-serial@vger.kernel.org Sender: linux-serial-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org Usage is as follows: myled=ledname tty=ttyS0 echo tty > /sys/class/leds/$myled/trigger cat /sys/class/tty/$tty/dev > /sys/class/leds/$myled/dev . When this new trigger is active it periodically checks the tty's statistics and when it changed since the last check the led is flashed once. Signed-off-by: Uwe Kleine-König --- drivers/leds/trigger/Kconfig | 7 ++ drivers/leds/trigger/Makefile | 1 + drivers/leds/trigger/ledtrig-tty.c | 153 +++++++++++++++++++++++++++++ 3 files changed, 161 insertions(+) create mode 100644 drivers/leds/trigger/ledtrig-tty.c diff --git a/drivers/leds/trigger/Kconfig b/drivers/leds/trigger/Kconfig index ce9429ca6dde..40ff08c93f56 100644 --- a/drivers/leds/trigger/Kconfig +++ b/drivers/leds/trigger/Kconfig @@ -144,4 +144,11 @@ config LEDS_TRIGGER_AUDIO the audio mute and mic-mute changes. If unsure, say N +config LEDS_TRIGGER_TTY + tristate "LED Trigger for TTY devices" + depends on TTY + help + This allows LEDs to be controlled by activity on ttys which includes + serial devices like /dev/ttyS0. + endif # LEDS_TRIGGERS diff --git a/drivers/leds/trigger/Makefile b/drivers/leds/trigger/Makefile index 733a83e2a718..25c4db97cdd4 100644 --- a/drivers/leds/trigger/Makefile +++ b/drivers/leds/trigger/Makefile @@ -15,3 +15,4 @@ obj-$(CONFIG_LEDS_TRIGGER_PANIC) += ledtrig-panic.o obj-$(CONFIG_LEDS_TRIGGER_NETDEV) += ledtrig-netdev.o obj-$(CONFIG_LEDS_TRIGGER_PATTERN) += ledtrig-pattern.o obj-$(CONFIG_LEDS_TRIGGER_AUDIO) += ledtrig-audio.o +obj-$(CONFIG_LEDS_TRIGGER_TTY) += ledtrig-tty.o diff --git a/drivers/leds/trigger/ledtrig-tty.c b/drivers/leds/trigger/ledtrig-tty.c new file mode 100644 index 000000000000..e9bbad52cc3f --- /dev/null +++ b/drivers/leds/trigger/ledtrig-tty.c @@ -0,0 +1,153 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include +#include +#include + +struct ledtrig_tty_data { + struct led_classdev *led_cdev; + struct delayed_work dwork; + struct tty_struct *tty; + dev_t device; + int rx, tx; +}; + +static void ledtrig_tty_halt(struct ledtrig_tty_data *trigger_data) +{ + cancel_delayed_work_sync(&trigger_data->dwork); +} + +static void ledtrig_tty_restart(struct ledtrig_tty_data *trigger_data) +{ + schedule_delayed_work(&trigger_data->dwork, 0); +} + +static ssize_t dev_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct ledtrig_tty_data *trigger_data = led_trigger_get_drvdata(dev); + ssize_t len = 0; + + if (trigger_data->tty) + len = sprintf(buf, "%d:%d\n", MAJOR(trigger_data->device), + MINOR(trigger_data->device)); + + return len; +} + +static ssize_t dev_store(struct device *dev, + struct device_attribute *attr, const char *buf, + size_t size) +{ + struct ledtrig_tty_data *trigger_data = led_trigger_get_drvdata(dev); + struct tty_struct *tty; + unsigned major, minor; + int ret; + + if (size == 0 || (size == 1 && buf[0] == '\n')) { + tty = NULL; + } else { + ret = sscanf(buf, "%u:%u", &major, &minor); + if (ret < 2) + return -EINVAL; + + tty = tty_kopen_shared(MKDEV(major, minor)); + if (IS_ERR(tty)) + return PTR_ERR(tty); + } + + ledtrig_tty_halt(trigger_data); + + tty_kref_put(trigger_data->tty); + trigger_data->tty = tty; + trigger_data->device = MKDEV(major, minor); + + if (tty) { + struct serial_icounter_struct icount; + ret = tty_get_icount(trigger_data->tty, &icount); + if (!ret) { + trigger_data->tx = icount.tx; + trigger_data->rx = icount.rx; + } + + ledtrig_tty_restart(trigger_data); + } + + return size; +} +static DEVICE_ATTR_RW(dev); + +static void ledtrig_tty_work(struct work_struct *work) +{ + struct ledtrig_tty_data *trigger_data = + container_of(work, struct ledtrig_tty_data, dwork.work); + struct serial_icounter_struct icount; + int ret; + + if (!trigger_data->tty) { + led_set_brightness(trigger_data->led_cdev, LED_OFF); + return; + } + + ret = tty_get_icount(trigger_data->tty, &icount); + if (ret) + return; + + if (icount.rx != trigger_data->rx || + icount.tx != trigger_data->tx) { + unsigned long delay_on = 100, delay_off = 100; + + led_blink_set_oneshot(trigger_data->led_cdev, + &delay_on, &delay_off, 0); + + trigger_data->rx = icount.rx; + trigger_data->tx = icount.tx; + } + + schedule_delayed_work(&trigger_data->dwork, msecs_to_jiffies(100)); +} + +static struct attribute *ledtrig_tty_attrs[] = { + &dev_attr_dev.attr, + NULL +}; +ATTRIBUTE_GROUPS(ledtrig_tty); + +static int ledtrig_tty_activate(struct led_classdev *led_cdev) +{ + struct ledtrig_tty_data *trigger_data; + + trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL); + if (!trigger_data) + return -ENOMEM; + + led_set_trigger_data(led_cdev, trigger_data); + + INIT_DELAYED_WORK(&trigger_data->dwork, ledtrig_tty_work); + trigger_data->led_cdev = led_cdev; + + return 0; +} + +static void ledtrig_tty_deactivate(struct led_classdev *led_cdev) +{ + struct ledtrig_tty_data *trigger_data = led_get_trigger_data(led_cdev); + + cancel_delayed_work_sync(&trigger_data->dwork); + + kfree(trigger_data); +} + +struct led_trigger ledtrig_tty = { + .name = "tty", + .activate = ledtrig_tty_activate, + .deactivate = ledtrig_tty_deactivate, + .groups = ledtrig_tty_groups, +}; +module_led_trigger(ledtrig_tty); + +MODULE_AUTHOR("Uwe Kleine-König "); +MODULE_DESCRIPTION("UART LED trigger"); +MODULE_LICENSE("GPL v2"); -- 2.24.0