From patchwork Mon Feb 8 13:53:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oleksij Rempel X-Patchwork-Id: 378722 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, 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 7331DC43381 for ; Mon, 8 Feb 2021 13:54:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4E52064E4F for ; Mon, 8 Feb 2021 13:54:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231722AbhBHNyk (ORCPT ); Mon, 8 Feb 2021 08:54:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35236 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231710AbhBHNye (ORCPT ); Mon, 8 Feb 2021 08:54:34 -0500 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 86EF0C061788 for ; Mon, 8 Feb 2021 05:53:53 -0800 (PST) Received: from dude.hi.pengutronix.de ([2001:67c:670:100:1d::7]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1l96z7-0006qK-Br; Mon, 08 Feb 2021 14:53:49 +0100 Received: from ore by dude.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1l96z6-0004pZ-KW; Mon, 08 Feb 2021 14:53:48 +0100 From: Oleksij Rempel To: Rob Herring , William Breathitt Gray Cc: Oleksij Rempel , Ahmad Fatoum , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Pengutronix Kernel Team , David Jander , Robin van der Gracht , linux-iio@vger.kernel.org, Linus Walleij , Jonathan Cameron Subject: [PATCH v5 2/2] counter: add IRQ or GPIO based event counter Date: Mon, 8 Feb 2021 14:53:47 +0100 Message-Id: <20210208135347.18494-3-o.rempel@pengutronix.de> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210208135347.18494-1-o.rempel@pengutronix.de> References: <20210208135347.18494-1-o.rempel@pengutronix.de> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::7 X-SA-Exim-Mail-From: ore@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: devicetree@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Add simple IRQ or GPIO base event counter. This device is used to measure rotation speed of some agricultural devices, so no high frequency on the counter pin is expected. The maximal measurement frequency depends on the CPU and system load. On the idle iMX6S I was able to measure up to 20kHz without count drops. Signed-off-by: Oleksij Rempel Reviewed-by: Ahmad Fatoum --- drivers/counter/Kconfig | 10 ++ drivers/counter/Makefile | 1 + drivers/counter/event-cnt.c | 250 ++++++++++++++++++++++++++++++++++++ 3 files changed, 261 insertions(+) create mode 100644 drivers/counter/event-cnt.c diff --git a/drivers/counter/Kconfig b/drivers/counter/Kconfig index 2de53ab0dd25..3284987e070a 100644 --- a/drivers/counter/Kconfig +++ b/drivers/counter/Kconfig @@ -29,6 +29,16 @@ config 104_QUAD_8 The base port addresses for the devices may be configured via the base array module parameter. +config EVENT_CNT + tristate "Event counter driver" + depends on GPIOLIB + help + Select this option to enable event counter driver. Any interrupt source + can be used by this driver as the event source. + + To compile this driver as a module, choose M here: the + module will be called gpio-pulse-cnt. + config STM32_TIMER_CNT tristate "STM32 Timer encoder counter driver" depends on MFD_STM32_TIMERS || COMPILE_TEST diff --git a/drivers/counter/Makefile b/drivers/counter/Makefile index 0a393f71e481..6626900468f6 100644 --- a/drivers/counter/Makefile +++ b/drivers/counter/Makefile @@ -6,6 +6,7 @@ obj-$(CONFIG_COUNTER) += counter.o obj-$(CONFIG_104_QUAD_8) += 104-quad-8.o +obj-$(CONFIG_EVENT_CNT) += event-cnt.o obj-$(CONFIG_STM32_TIMER_CNT) += stm32-timer-cnt.o obj-$(CONFIG_STM32_LPTIMER_CNT) += stm32-lptimer-cnt.o obj-$(CONFIG_TI_EQEP) += ti-eqep.o diff --git a/drivers/counter/event-cnt.c b/drivers/counter/event-cnt.c new file mode 100644 index 000000000000..a394fe72c4e4 --- /dev/null +++ b/drivers/counter/event-cnt.c @@ -0,0 +1,250 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2021 Pengutronix, Oleksij Rempel + */ + +#include +#include +#include +#include +#include +#include +#include + +#define EVENT_CNT_NAME "event-cnt" + +struct event_cnt_priv { + struct counter_device counter; + struct counter_ops ops; + struct gpio_desc *gpio; + int irq; + bool enabled; + atomic_t count; +}; + +static irqreturn_t event_cnt_isr(int irq, void *dev_id) +{ + struct event_cnt_priv *priv = dev_id; + + atomic_inc(&priv->count); + + return IRQ_HANDLED; +} + +static ssize_t event_cnt_enable_read(struct counter_device *counter, + struct counter_count *count, void *private, + char *buf) +{ + struct event_cnt_priv *priv = counter->priv; + + return sysfs_emit(buf, "%d\n", priv->enabled); +} + +static ssize_t event_cnt_enable_write(struct counter_device *counter, + struct counter_count *count, + void *private, const char *buf, + size_t len) +{ + struct event_cnt_priv *priv = counter->priv; + bool enable; + ssize_t ret; + + ret = kstrtobool(buf, &enable); + if (ret) + return ret; + + if (priv->enabled == enable) + return len; + + if (enable) { + priv->enabled = enable; + enable_irq(priv->irq); + } else { + disable_irq(priv->irq); + priv->enabled = enable; + } + + return len; +} + +static const struct counter_count_ext event_cnt_ext[] = { + { + .name = "enable", + .read = event_cnt_enable_read, + .write = event_cnt_enable_write, + }, +}; + +static enum counter_synapse_action event_cnt_synapse_actionss[] = { + COUNTER_SYNAPSE_ACTION_RISING_EDGE, +}; + +static int event_cnt_action_get(struct counter_device *counter, + struct counter_count *count, + struct counter_synapse *synapse, + size_t *action) +{ + *action = COUNTER_SYNAPSE_ACTION_RISING_EDGE; + + return 0; +} + +static int event_cnt_read(struct counter_device *counter, + struct counter_count *count, + unsigned long *val) +{ + struct event_cnt_priv *priv = counter->priv; + + *val = atomic_read(&priv->count); + + return 0; +} + +static int event_cnt_write(struct counter_device *counter, + struct counter_count *count, + const unsigned long val) +{ + struct event_cnt_priv *priv = counter->priv; + + atomic_set(&priv->count, val); + + return 0; +} + +static int event_cnt_function_get(struct counter_device *counter, + struct counter_count *count, size_t *function) +{ + *function = COUNTER_COUNT_FUNCTION_INCREASE; + + return 0; +} + +static int event_cnt_signal_read(struct counter_device *counter, + struct counter_signal *signal, + enum counter_signal_value *val) +{ + struct event_cnt_priv *priv = counter->priv; + int ret; + + ret = gpiod_get_value(priv->gpio); + if (ret < 0) + return ret; + + *val = ret ? COUNTER_SIGNAL_HIGH : COUNTER_SIGNAL_LOW; + + return 0; +} + +static struct counter_signal event_cnt_signals[] = { + { + .id = 0, + .name = "Channel 0 signal", + }, +}; + +static struct counter_synapse event_cnt_synapses[] = { + { + .actions_list = event_cnt_synapse_actionss, + .num_actions = ARRAY_SIZE(event_cnt_synapse_actionss), + .signal = &event_cnt_signals[0] + }, +}; + +static enum counter_count_function event_cnt_functions[] = { + COUNTER_COUNT_FUNCTION_INCREASE, +}; + +static struct counter_count event_cnts[] = { + { + .id = 0, + .name = "Channel 1 Count", + .functions_list = event_cnt_functions, + .num_functions = ARRAY_SIZE(event_cnt_functions), + .synapses = event_cnt_synapses, + .num_synapses = ARRAY_SIZE(event_cnt_synapses), + .ext = event_cnt_ext, + .num_ext = ARRAY_SIZE(event_cnt_ext), + }, +}; + +static int event_cnt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct event_cnt_priv *priv; + int ret; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->irq = platform_get_irq_optional(pdev, 0); + if (priv->irq == -ENXIO) + priv->irq = 0; + else if (priv->irq < 0) + return dev_err_probe(dev, priv->irq, "failed to get IRQ\n"); + + priv->gpio = devm_gpiod_get_optional(dev, NULL, GPIOD_IN); + if (IS_ERR(priv->gpio)) + return dev_err_probe(dev, PTR_ERR(priv->gpio), "failed to get GPIO\n"); + + if (!priv->irq && !priv->gpio) { + dev_err(dev, "IRQ and GPIO are not found. At least one source should be provided\n"); + return -ENODEV; + } + + if (!priv->irq) { + int irq = gpiod_to_irq(priv->gpio); + + if (irq < 0) + return dev_err_probe(dev, irq, "failed to get IRQ from GPIO\n"); + + priv->irq = irq; + } + + priv->ops.action_get = event_cnt_action_get; + priv->ops.count_read = event_cnt_read; + priv->ops.count_write = event_cnt_write; + priv->ops.function_get = event_cnt_function_get; + if (priv->gpio) + priv->ops.signal_read = event_cnt_signal_read; + + priv->counter.name = dev_name(dev); + priv->counter.parent = dev; + priv->counter.ops = &priv->ops; + priv->counter.counts = event_cnts; + priv->counter.num_counts = ARRAY_SIZE(event_cnts); + priv->counter.signals = event_cnt_signals; + priv->counter.num_signals = ARRAY_SIZE(event_cnt_signals); + priv->counter.priv = priv; + + irq_set_status_flags(priv->irq, IRQ_NOAUTOEN); + ret = devm_request_irq(dev, priv->irq, event_cnt_isr, + IRQF_TRIGGER_RISING | IRQF_NO_THREAD, + EVENT_CNT_NAME, priv); + if (ret) + return ret; + + platform_set_drvdata(pdev, priv); + + return devm_counter_register(dev, &priv->counter); +} + +static const struct of_device_id event_cnt_of_match[] = { + { .compatible = "event-counter", }, + {} +}; +MODULE_DEVICE_TABLE(of, event_cnt_of_match); + +static struct platform_driver event_cnt_driver = { + .probe = event_cnt_probe, + .driver = { + .name = EVENT_CNT_NAME, + .of_match_table = event_cnt_of_match, + }, +}; +module_platform_driver(event_cnt_driver); + +MODULE_ALIAS("platform:event-counter"); +MODULE_AUTHOR("Oleksij Rempel "); +MODULE_DESCRIPTION("Event counter driver"); +MODULE_LICENSE("GPL v2");