From patchwork Fri Jan 22 11:24:34 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oleksij Rempel X-Patchwork-Id: 12039067 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=unavailable 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 BDE19C433E0 for ; Fri, 22 Jan 2021 11:32:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 775A1235E4 for ; Fri, 22 Jan 2021 11:32:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728349AbhAVLc3 (ORCPT ); Fri, 22 Jan 2021 06:32:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41676 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728120AbhAVLaN (ORCPT ); Fri, 22 Jan 2021 06:30:13 -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 2447DC061351 for ; Fri, 22 Jan 2021 03:27:04 -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 1l2uae-0000Ww-Im; Fri, 22 Jan 2021 12:26:56 +0100 Received: from ore by dude.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1l2uae-0007dO-2n; Fri, 22 Jan 2021 12:26:56 +0100 From: Oleksij Rempel To: Rob Herring , William Breathitt Gray Cc: Oleksij Rempel , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Pengutronix Kernel Team , David Jander , Robin van der Gracht , linux-iio@vger.kernel.org Subject: [PATCH v3 2/2] counter: add GPIO based pulse counters Date: Fri, 22 Jan 2021 12:24:34 +0100 Message-Id: <20210122112434.27886-3-o.rempel@pengutronix.de> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210122112434.27886-1-o.rempel@pengutronix.de> References: <20210122112434.27886-1-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: linux-iio@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org Add simple GPIO base pulse 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 | 9 ++ drivers/counter/Makefile | 1 + drivers/counter/gpio-pulse-cnt.c | 244 +++++++++++++++++++++++++++++++ 3 files changed, 254 insertions(+) create mode 100644 drivers/counter/gpio-pulse-cnt.c diff --git a/drivers/counter/Kconfig b/drivers/counter/Kconfig index 2de53ab0dd25..9ad1d9d49dd1 100644 --- a/drivers/counter/Kconfig +++ b/drivers/counter/Kconfig @@ -29,6 +29,15 @@ config 104_QUAD_8 The base port addresses for the devices may be configured via the base array module parameter. +config GPIO_PULSE_CNT + tristate "GPIO pulse counter driver" + depends on GPIOLIB + help + Select this option to enable GPIO pulse counter driver. + + 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..6a5c3fc6f2a0 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-$(CONFIG_GPIO_PULSE_CNT) += gpio-pulse-cnt.o obj-$(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/gpio-pulse-cnt.c b/drivers/counter/gpio-pulse-cnt.c new file mode 100644 index 000000000000..9454345c77ad --- /dev/null +++ b/drivers/counter/gpio-pulse-cnt.c @@ -0,0 +1,244 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2021 Pengutronix, Oleksij Rempel + */ + +#include +#include +#include +#include +#include +#include + +#define GPIO_PULSE_NAME "gpio-pulse-counter" + +struct gpio_pulse_priv { + struct counter_device counter; + struct gpio_desc *gpio; + int irq; + bool enabled; + atomic_t count; +}; + +static irqreturn_t gpio_pulse_irq_isr(int irq, void *dev_id) +{ + struct gpio_pulse_priv *priv = dev_id; + + if (!priv->enabled) + return IRQ_NONE; + + atomic_inc(&priv->count); + + return IRQ_HANDLED; +} + +static ssize_t gpio_pulse_count_enable_read(struct counter_device *counter, + struct counter_count *count, + void *private, char *buf) +{ + struct gpio_pulse_priv *priv = counter->priv; + + return sysfs_emit(buf, "%d\n", priv->enabled); +} + +static ssize_t gpio_pulse_count_enable_write(struct counter_device *counter, + struct counter_count *count, + void *private, + const char *buf, size_t len) +{ + struct gpio_pulse_priv *priv = counter->priv; + bool enable; + ssize_t ret; + + ret = kstrtobool(buf, &enable); + if (ret) + return ret; + + if (priv->enabled == enable) + return len; + + priv->enabled = enable; + + if (enable) + enable_irq(priv->irq); + else + disable_irq(priv->irq); + + return len; +} + +static const struct counter_count_ext gpio_pulse_count_ext[] = { + { + .name = "enable", + .read = gpio_pulse_count_enable_read, + .write = gpio_pulse_count_enable_write, + }, +}; + +static enum counter_synapse_action gpio_pulse_synapse_actions[] = { + COUNTER_SYNAPSE_ACTION_RISING_EDGE, +}; + +static int gpio_pulse_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 gpio_pulse_count_read(struct counter_device *counter, + struct counter_count *count, + unsigned long *val) +{ + struct gpio_pulse_priv *priv = counter->priv; + + *val = atomic_read(&priv->count); + + return 0; +} + +static int gpio_pulse_count_write(struct counter_device *counter, + struct counter_count *count, + const unsigned long val) +{ + struct gpio_pulse_priv *priv = counter->priv; + + atomic_set(&priv->count, val); + + return 0; +} + +static int gpio_pulse_count_function_get(struct counter_device *counter, + struct counter_count *count, + size_t *function) +{ + *function = COUNTER_COUNT_FUNCTION_INCREASE; + + return 0; +} + +static int gpio_pulse_count_signal_read(struct counter_device *counter, + struct counter_signal *signal, + enum counter_signal_value *val) +{ + struct gpio_pulse_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 const struct counter_ops gpio_pulse_cnt_ops = { + .action_get = gpio_pulse_action_get, + .count_read = gpio_pulse_count_read, + .count_write = gpio_pulse_count_write, + .function_get = gpio_pulse_count_function_get, + .signal_read = gpio_pulse_count_signal_read, +}; + +static struct counter_signal gpio_pulse_signals[] = { + { + .id = 0, + .name = "Channel 0 signal", + }, +}; + +static struct counter_synapse gpio_pulse_count_synapses[] = { + { + .actions_list = gpio_pulse_synapse_actions, + .num_actions = ARRAY_SIZE(gpio_pulse_synapse_actions), + .signal = &gpio_pulse_signals[0] + }, +}; + +static enum counter_count_function gpio_pulse_count_functions[] = { + COUNTER_COUNT_FUNCTION_INCREASE, +}; + +static struct counter_count gpio_pulse_counts[] = { + { + .id = 0, + .name = "Channel 1 Count", + .functions_list = gpio_pulse_count_functions, + .num_functions = ARRAY_SIZE(gpio_pulse_count_functions), + .synapses = gpio_pulse_count_synapses, + .num_synapses = ARRAY_SIZE(gpio_pulse_count_synapses), + .ext = gpio_pulse_count_ext, + .num_ext = ARRAY_SIZE(gpio_pulse_count_ext), + }, +}; + +static int gpio_pulse_cnt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct gpio_pulse_priv *priv; + int ret; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + if (gpiod_count(dev, NULL) != 1) { + dev_err(dev, "Error, need exactly 1 gpio for device\n"); + return -EINVAL; + } + + priv->gpio = devm_gpiod_get(dev, NULL, GPIOD_IN); + if (IS_ERR(priv->gpio)) + return dev_err_probe(dev, PTR_ERR(priv->gpio), "failed to get gpio\n"); + + priv->irq = gpiod_to_irq(priv->gpio); + if (priv->irq < 0) { + dev_err(dev, "failed to map GPIO to IRQ: %d\n", priv->irq); + return priv->irq; + } + + priv->counter.name = dev_name(dev); + priv->counter.parent = dev; + priv->counter.ops = &gpio_pulse_cnt_ops; + priv->counter.counts = gpio_pulse_counts; + priv->counter.num_counts = ARRAY_SIZE(gpio_pulse_counts); + priv->counter.signals = gpio_pulse_signals; + priv->counter.num_signals = ARRAY_SIZE(gpio_pulse_signals); + priv->counter.priv = priv; + + ret = devm_request_irq(dev, priv->irq, gpio_pulse_irq_isr, + IRQF_TRIGGER_RISING | IRQF_NO_THREAD, + GPIO_PULSE_NAME, priv); + if (ret) + return ret; + + disable_irq(priv->irq); + + platform_set_drvdata(pdev, priv); + + return devm_counter_register(dev, &priv->counter); +} + +static const struct of_device_id gpio_pulse_cnt_of_match[] = { + { .compatible = "virtual,gpio-pulse-counter", }, + {} +}; +MODULE_DEVICE_TABLE(of, gpio_pulse_cnt_of_match); + +static struct platform_driver gpio_pulse_cnt_driver = { + .probe = gpio_pulse_cnt_probe, + .driver = { + .name = GPIO_PULSE_NAME, + .of_match_table = gpio_pulse_cnt_of_match, + }, +}; +module_platform_driver(gpio_pulse_cnt_driver); + +MODULE_ALIAS("platform:gpio-pulse-counter"); +MODULE_AUTHOR("Oleksij Rempel "); +MODULE_DESCRIPTION("GPIO pulse counter driver"); +MODULE_LICENSE("GPL v2");