From patchwork Sat Mar 29 16:49:03 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: gyeyoung X-Patchwork-Id: 14032744 Received: from mail-pl1-f178.google.com (mail-pl1-f178.google.com [209.85.214.178]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 50F5C13C3C2; Sat, 29 Mar 2025 16:50:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.178 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743267006; cv=none; b=fmJTsLEddnsr4feCaHnAAe+kKrThPtKZDzUd0VxvWUCUxPWSeFVdxfaZXJ68+eB0RwPcO4ADi7g57XfBnyiXCzjidkO9m8Xm8fjZLRVCsYdkHnFPWvCdDCdaAcikvOPiLqVB2gSzTYckYYyD/vEhmXc5irsGRnoPKSfhBlMMsHU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743267006; c=relaxed/simple; bh=Io7vP41mShDkpq9IpHddHFPNw2pL0+VFdDMCwIagwW8=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=MKl2GGXxB79tcuxd+Y8RxUqpbrEfivRC8lGR1N57KtHnX/E1kl9YNQ2C117Pt0F/kutDe3ZTsVDNAZrv8LY8w4DbRETYtigVs35ObhlXMCxM+XSB6F72Rpd9+Ig0SZ+sbLF8V2AmF0s+VbeE4G3NSfV7ZKBbC/7A4S+bfr1Flx8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=g5mCF88r; arc=none smtp.client-ip=209.85.214.178 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="g5mCF88r" Received: by mail-pl1-f178.google.com with SMTP id d9443c01a7336-224171d6826so28656735ad.3; Sat, 29 Mar 2025 09:50:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1743267003; x=1743871803; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=71Np5SPg0AoFK/g+sMzVtj0g8qAJE0RDXtdJ4KQUhws=; b=g5mCF88run0BQ5mWUvPZ67AbUJBwT9WxRu87LSSWXm8xPyb8Mj5M4Qtp0/CnVa/Gca 38dP1oZsaxAVhJGK/2x3eXn2jjMG2dKcojUJMaas9OZsA/8XA/DWByk6vhkCAmcZO9nJ bwmW7xHAT/0khfDe0fI9Xxu+5esShXEJS0djfSHUXliQRgV66pwSlVhvv83zkfsq/aH8 pKZju1TbqZP9Uw0WO5129iWUvkf8zgRHfq5vBYW0nmYeR2QDnswL4afqW3CGkh2RppVj t6cWDC3b9RS76IYQViDLiLor0v04YANbWj/gmMMa2fXwgf1Bt8gJb70DpZjo17V4+IY/ 4Ftg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1743267003; x=1743871803; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=71Np5SPg0AoFK/g+sMzVtj0g8qAJE0RDXtdJ4KQUhws=; b=d2sGevzwbrhpSAY9q1GXn3hFbnRag5nNhqIHsBCAMZ8c9cO6hUepcCKCYkPfytgiha 2jKC5qZmWfbeY7TRs5OtvxhLjjqtk+YCWxPiZ72BDhLKvwAyN8NU1ayGlhEw4acelETn gu3Jsz5ErfBhTUZeeh6f/SZ2NuLTnOO/WQQ5AcAElFXq5cjv+XkL+GFboAlG4rqAQh08 e91M+uSbotIW3cppvfQe2DBRxEnCnzwcGQyKXNfSTIQ5/YeQ2+AHVp7ZA3/3nDcVQkkV 7usmxEwXTdtRogVN78GrOd9uGf9AqzoSuhl2UQtp9/Jx44BKrxCqLd0QrPZprT9cpTK9 widg== X-Forwarded-Encrypted: i=1; AJvYcCVfejU3FPIQmxHtzJ4d0T/7qg1CdyHQecUxnuiQOf82AzE9lIi37yRETAvaWmVli5WKBJnWafwf3Enx@vger.kernel.org, AJvYcCXQmBeyVqLH8lNf1dgvOucjcLIaGxda2AhFF+mD73/nF8fJd5UfWItT02nGQ/4KsxVST7hQIDaJPOx3@vger.kernel.org X-Gm-Message-State: AOJu0Yz8ra3m42amYm+JUBo0xmdmXDQA9nQMX1qi0pTvF4jTIGmN2UFv bDEq3s0i3h5gqVGHOPbs65j93iqqikwrPYuz5a3EeqcZKSPMn3Pp X-Gm-Gg: ASbGnculhjNYkVij00qkwQZTag6yureN90Wbcg0pN0wYozuAFVQLDECVM3VUGFCi5Jm kkstJrwEx7fRa06Ptt75nmyTSDs6kIjNc8jyqJe/sVLbr/jnUpUaaaHsuTLcR30p4S/1uhpuFtd PkSfweaa2QHX0GTdKakpPhS3unpPy9vVlDAKlgGf78F7ysAujpFgC3xaDtmVBufK3rKKw/U/H8n hcCHd4Ng0eKJXg47DqSw98Dvvzcvootc8fWfFKBg7pFmcSRy7itiRFTEsZLDaBZ75/XGtOx8sCN SceQyD8ufImZc456KwqLzD+hnzjalngWd4qYYakzXR8yJx1nZQxdKLqXRQqj7g== X-Google-Smtp-Source: AGHT+IG73kQVw5sY7LET7IJmP0loG/EZoo/cH3A6ETK76akY6rymFdZsum0mX5uGXTv89QsrLLe+NA== X-Received: by 2002:a17:902:f70f:b0:220:e1e6:4472 with SMTP id d9443c01a7336-2292f9547b4mr51086755ad.13.1743267003609; Sat, 29 Mar 2025 09:50:03 -0700 (PDT) Received: from gye-ThinkPad-T590.. ([39.120.225.141]) by smtp.googlemail.com with ESMTPSA id d9443c01a7336-2291eec6fb2sm38565425ad.26.2025.03.29.09.50.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 29 Mar 2025 09:50:03 -0700 (PDT) From: Gyeyoung Baek To: jic23@kernel.org Cc: Gyeyoung Baek , linux-iio@vger.kernel.org, devicetree@vger.kernel.org, lars@metafoo.de, gustavograzs@gmail.com, javier.carrasco.cruz@gmail.com, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org Subject: [PATCH 1/3] iio: chemical: add support for winsen MHZ19B CO2 sensor Date: Sun, 30 Mar 2025 01:49:03 +0900 Message-Id: <20250329164905.632491-2-gye976@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250329164905.632491-1-gye976@gmail.com> References: <20250329164905.632491-1-gye976@gmail.com> Precedence: bulk X-Mailing-List: linux-iio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Add support for winsen MHZ19B CO2 sensor. Signed-off-by: Gyeyoung Baek --- drivers/iio/chemical/Kconfig | 6 + drivers/iio/chemical/Makefile | 1 + drivers/iio/chemical/mhz19b.c | 354 ++++++++++++++++++++++++++++++++++ 3 files changed, 361 insertions(+) create mode 100644 drivers/iio/chemical/mhz19b.c diff --git a/drivers/iio/chemical/Kconfig b/drivers/iio/chemical/Kconfig index 330fe0af946f..6b09a9c52f32 100644 --- a/drivers/iio/chemical/Kconfig +++ b/drivers/iio/chemical/Kconfig @@ -108,6 +108,12 @@ config IAQCORE iAQ-Core Continuous/Pulsed VOC (Volatile Organic Compounds) sensors +config MHZ19B + tristate "MHZ19B CO2 sensor" + depends on SERIAL_DEV_BUS + help + Say Y here to build support for the MHZ19B CO2 sensor. + + To compile this driver as a module, choose M here: the module will + be called scd4x. + config PMS7003 tristate "Plantower PMS7003 particulate matter sensor" depends on SERIAL_DEV_BUS diff --git a/drivers/iio/chemical/Makefile b/drivers/iio/chemical/Makefile index 4866db06bdc9..c63daebf39ac 100644 --- a/drivers/iio/chemical/Makefile +++ b/drivers/iio/chemical/Makefile @@ -15,6 +15,7 @@ obj-$(CONFIG_ENS160) += ens160_core.o obj-$(CONFIG_ENS160_I2C) += ens160_i2c.o obj-$(CONFIG_ENS160_SPI) += ens160_spi.o obj-$(CONFIG_IAQCORE) += ams-iaq-core.o +obj-$(CONFIG_MHZ19B) += mhz19b.o obj-$(CONFIG_PMS7003) += pms7003.o obj-$(CONFIG_SCD30_CORE) += scd30_core.o obj-$(CONFIG_SCD30_I2C) += scd30_i2c.o diff --git a/drivers/iio/chemical/mhz19b.c b/drivers/iio/chemical/mhz19b.c new file mode 100644 index 000000000000..de900131035b --- /dev/null +++ b/drivers/iio/chemical/mhz19b.c @@ -0,0 +1,354 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * mh-z19b co2 sensor driver + * + * Copyright (c) 2025 Gyeyoung Baek + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct mhz19b_state { + struct serdev_device *serdev; + + /* serdev receive buffer */ + char buf[9]; + int buf_idx; + + /* protect access to mhz19b_state */ + struct mutex lock; +}; + +/* ABC logig on/off */ +#define MHZ19B_ABC_LOGIC_CMD 0x79 +/* read CO2 concentration */ +#define MHZ19B_READ_CO2_CMD 0x86 +/* calibrate Zero Point */ +#define MHZ19B_ZERO_POINT_CMD 0x87 +/* calibrate Span Point */ +#define MHZ19B_SPAN_POINT_CMD 0x88 +/* set sensor detection range */ +#define MHZ19B_DETECTION_RANGE_CMD 0x99 + +#define MHZ19B_CMD_SIZE 9 + +static uint8_t mhz19b_get_checksum(uint8_t *packet) +{ + uint8_t i, checksum = 0; + + for (i = 1; i < 8; i++) + checksum += packet[i]; + + checksum = 0xff - checksum; + checksum += 1; + + return checksum; +} + +static int mhz19b_serdev_cmd(struct iio_dev *indio_dev, int cmd, const char *str) +{ + int ret = 0; + struct serdev_device *serdev; + struct mhz19b_state *mhz19b; + struct device *dev; + + mhz19b = iio_priv(indio_dev); + serdev = mhz19b->serdev; + dev = &indio_dev->dev; + + /* + * commands have following format: + * + * +------+------+-----+------+------+------+------+------+-------+ + * | 0xFF | 0x01 | cmd | arg0 | arg1 | 0x00 | 0x00 | 0x00 | cksum | + * +------+------+-----+------+------+------+------+------+-------+ + */ + uint8_t cmd_buf[MHZ19B_CMD_SIZE] = { + 0xFF, 0x01, cmd, + }; + + switch (cmd) { + case MHZ19B_ABC_LOGIC_CMD: + { + bool enable; + + ret = kstrtobool(str, &enable); + if (ret) + return ret; + + cmd_buf[3] = enable ? 0xA0 : 0x00; + break; + } + case MHZ19B_SPAN_POINT_CMD: + { + uint16_t ppm; + + ret = kstrtou16(str, 10, &ppm); + if (ret) + return ret; + + /* at least 1000ppm */ + if (ppm < 1000 || ppm > 5000) { + dev_dbg(&indio_dev->dev, "span point ppm should be 1000~5000"); + return -EINVAL; + } + + cmd_buf[3] = ppm / 256; + cmd_buf[4] = ppm % 256; + break; + } + case MHZ19B_DETECTION_RANGE_CMD: + { + uint16_t range; + + ret = kstrtou16(str, 10, &range); + if (ret) + return ret; + + /* Detection Range should be 2000 or 5000 */ + if (!(range == 2000 || range == 5000)) { + dev_dbg(&indio_dev->dev, "detection range should be 2000 or 5000"); + return -EINVAL; + } + + cmd_buf[3] = range / 256; + cmd_buf[4] = range % 256; + break; + } + default: + break; + } + cmd_buf[MHZ19B_CMD_SIZE - 1] = mhz19b_get_checksum(cmd_buf); + + scoped_guard(mutex, &mhz19b->lock) { + ret = serdev_device_write(serdev, cmd_buf, MHZ19B_CMD_SIZE, 0); + mhz19b->buf_idx = 0; + + if (ret != MHZ19B_CMD_SIZE) { + dev_err(dev, "write err, %d bytes written", ret); + return -EINVAL; + } + + switch (cmd) { + case MHZ19B_READ_CO2_CMD: + if (mhz19b->buf[MHZ19B_CMD_SIZE - 1] != mhz19b_get_checksum(mhz19b->buf)) { + dev_err(dev, "checksum err"); + return -EINVAL; + } + + ret = (mhz19b->buf[2] << 8) + mhz19b->buf[3]; + break; + default: + /* no response commands. */ + ret = 0; + break; + } + } + + return ret; +} + +static int mhz19b_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct mhz19b_state *mhz19b; + int ret; + + mhz19b = iio_priv(indio_dev); + + ret = mhz19b_serdev_cmd(indio_dev, MHZ19B_READ_CO2_CMD, NULL); + if (ret < 0) + return ret; + + *val = ret; + return IIO_VAL_INT; +} + +static const struct iio_info mhz19b_info = { + .read_raw = mhz19b_read_raw, +}; + +static ssize_t mhz19b_zero_point_write(struct iio_dev *iiodev, + uintptr_t private, const struct iio_chan_spec *chan, + const char *buf, size_t len) +{ + int ret; + + ret = mhz19b_serdev_cmd(iiodev, MHZ19B_ZERO_POINT_CMD, buf); + if (ret < 0) + return ret; + + return len; +} + +static ssize_t mhz19b_span_point_write(struct iio_dev *iiodev, + uintptr_t private, const struct iio_chan_spec *chan, + const char *buf, size_t len) +{ + int ret; + + ret = mhz19b_serdev_cmd(iiodev, MHZ19B_SPAN_POINT_CMD, buf); + if (ret < 0) + return ret; + + return len; +} + +static ssize_t mhz19b_abc_logic_write(struct iio_dev *iiodev, + uintptr_t private, const struct iio_chan_spec *chan, + const char *buf, size_t len) +{ + int ret; + + ret = mhz19b_serdev_cmd(iiodev, MHZ19B_ABC_LOGIC_CMD, buf); + if (ret < 0) + return ret; + + return len; +} + +struct iio_chan_spec_ext_info mhz19b_co2_ext_info[] = { + { + .name = "zero_point", + .write = mhz19b_zero_point_write, + }, + { + .name = "span_point", + .write = mhz19b_span_point_write, + }, + { + .name = "abc_logic", + .write = mhz19b_abc_logic_write, + }, + {} +}; + +static const struct iio_chan_spec mhz19b_channels[] = { + { + .type = IIO_CONCENTRATION, + .channel2 = IIO_MOD_CO2, + .modified = 1, + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), + + .ext_info = mhz19b_co2_ext_info, + }, +}; + +static int mhz19b_core_probe(struct device *dev) +{ + int ret; + + struct serdev_device *serdev; + struct mhz19b_state *mhz19b; + struct iio_dev *indio_dev; + + indio_dev = devm_iio_device_alloc(dev, sizeof(struct mhz19b_state)); + if (indio_dev == NULL) + return ret; + + dev_set_drvdata(dev, indio_dev); + + mhz19b = iio_priv(indio_dev); + + mhz19b->buf_idx = 0; + ret = devm_mutex_init(dev, &mhz19b->lock); + if (ret) + return ret; + + serdev = container_of(dev, struct serdev_device, dev); + + mhz19b->serdev = serdev; + + indio_dev->name = "mh-z19b"; + indio_dev->channels = mhz19b_channels; + indio_dev->num_channels = ARRAY_SIZE(mhz19b_channels); + indio_dev->info = &mhz19b_info; + + ret = devm_iio_device_register(dev, indio_dev); + if (ret) + return ret; + + return 0; +} + +static size_t mhz19b_receive_buf(struct serdev_device *serdev, const u8 *data, size_t len) +{ + struct iio_dev *indio_dev; + struct mhz19b_state *mhz19b; + + indio_dev = dev_get_drvdata(&serdev->dev); + mhz19b = iio_priv(indio_dev); + + for (int i = 0; i < len; i++) + mhz19b->buf[mhz19b->buf_idx++] = data[i]; + + return len; +} + +static void mhz19b_write_wakeup(struct serdev_device *serdev) +{ + struct iio_dev *indio_dev; + + indio_dev = dev_get_drvdata(&serdev->dev); + + dev_dbg(&indio_dev->dev, "mhz19b_write_wakeup"); +} + +static const struct serdev_device_ops mhz19b_ops = { + .receive_buf = mhz19b_receive_buf, + .write_wakeup = mhz19b_write_wakeup, +}; + +static int mhz19b_probe(struct serdev_device *serdev) +{ + int ret; + + struct device *dev; + + dev = &serdev->dev; + serdev_device_set_client_ops(serdev, &mhz19b_ops); + + ret = devm_serdev_device_open(dev, serdev); + if (ret) + return ret; + + serdev_device_set_baudrate(serdev, 9600); + serdev_device_set_flow_control(serdev, false); + ret = serdev_device_set_parity(serdev, SERDEV_PARITY_NONE); + if (ret < 0) + return ret; + + ret = mhz19b_core_probe(dev); + if (ret) + return ret; + + return 0; +} + +static const struct of_device_id mhz19b_of_match[] = { + { .compatible = "winsen,mhz19b", }, + {} +}; + +MODULE_DEVICE_TABLE(of, mhz19b_of_match); + +static struct serdev_device_driver mhz19b_driver = { + .driver = { + .name = "mhz19b", + .of_match_table = mhz19b_of_match, + }, + .probe = mhz19b_probe, +}; + +module_serdev_device_driver(mhz19b_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Gyeyoung Baek"); +MODULE_DESCRIPTION("MH-Z19B CO2 sensor driver using serdev interface");