From patchwork Fri Jun 7 10:39:45 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Antoni Pokusinski X-Patchwork-Id: 13689668 Received: from mail-wr1-f54.google.com (mail-wr1-f54.google.com [209.85.221.54]) (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 A8C5815D5C4; Fri, 7 Jun 2024 10:40:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.54 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717756853; cv=none; b=P/BfR6xs7dqxXAj/RnGmlFbnLv9LcgEzvrNDg0rdusyWkVcgnSSvNYLbr3835jE6f3mOb8Z9tF6XrFsRtBNtpgQ4MjaRUC06hNilo2qDoiib3NkxR5pZvU9/kkI4cFjF8NztEUfWHRHZNTLAyWnvxqT7JbohHNreBJL1EZcAsvA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717756853; c=relaxed/simple; bh=UynYF8JW/N9DYyJC+f4j3JHrpHyBb40KUm2kws6VKh0=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=ddonD1kYKqRl5CjhNgcMRppIp3kW1MA4jVEkl0It9ZFpb2wX/kt5X4nTpjUGt41odnCGbObWi8/zij4Sc0oKaCIhVn3/DMCLZQH4LGFEi833Z+zzFeAAeMghKpbYUsF0Q9vdGsLOHlLv2fo15s790skwMIeUwfgpuK3TMGVBMdI= 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=YLsL13wL; arc=none smtp.client-ip=209.85.221.54 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="YLsL13wL" Received: by mail-wr1-f54.google.com with SMTP id ffacd0b85a97d-35e4aaa0f33so1986578f8f.0; Fri, 07 Jun 2024 03:40:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1717756850; x=1718361650; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=Kz+LCmEdD3MpY9rq5ZseyIHOMygig8X78a8YfUFrEaM=; b=YLsL13wLv5d31hrh3JkWo2MEqXaoGr8v4Z/OzgRACeGqkZwxR9wlv+rCoroFFJqt/K ipAR0zSm4K8BIe0ZsoCiydr+qn6wXqWXNiIbHhpLGfEPzx8EYKo57/2S/QkS8uJpZWza M9SFqsKaqEB5N8SrieRfc+tLa6YLzrXcdQWgu2kY1fWok22Hk38xDenlko9GadUAAwGq gHKmbzLDs+2rcAoqttTUyMzuBzxpaaxIc7bu9QHLOUZWdvLVXnjhCJQCGD8imogqozgD bUQ5s5i9U4dc8tI4Rb/1SbSZku+pHlWAVurONRnNUxkUQfUZDOLQEvaW4x7+WKhajKhR RyGA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1717756850; x=1718361650; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=Kz+LCmEdD3MpY9rq5ZseyIHOMygig8X78a8YfUFrEaM=; b=wq7FPbET/ImaidHclVbW9JIaJ308TbjZzPurmMv3z6RtlD2UKxtt05qgpKQHstThOw hr6QFIeT7KjWFlsoeT2Z48smdawhcHdTOJFhfkQI2DlvSZog1LeYtRxiLkqWEbRx0TnC wmavpb03BmDhlerbVHkh+VUES8WooU5uVcbrx8CJrG2wllT5X8WNuRy4QG+ENeLhemBn i3AVImhEEEnmBT+BGVWf3x+SVAj2b73n4PUqfG8vslY9pqC0Adorrgex48+9OKHHhEUZ aPGlzgYvFh7JyxdHlpGQYzwDznxTpVZF7+nUogSEToVOPQJp/V0LYuvI07Fd6y5r8+YT S6JA== X-Forwarded-Encrypted: i=1; AJvYcCVrmh/ZgSSG7fwVhw6rlNBTvrnyowYVvEwa8bAvkVKMjSU1rke+dr2ODhyqgrAP5lQc07422uRpeF70oTeOTWSs7dLt7s54ZoQz X-Gm-Message-State: AOJu0YzYrQbpeKceUf6Xiy827M+aJoQDtl22JxApusAIodsIVrIGdEG+ Pek1FfALaZw06/yfANP6kxFAgGgwhcMIqBFFWd7z65zXERZzLQ/p X-Google-Smtp-Source: AGHT+IFWrSsV98lABxtAWuYUuhaUhOEgnia9rghGWKGQ3beuppFQ0JQ+p1ULcJ5bOdLbp2II/lu7CQ== X-Received: by 2002:a05:6000:45:b0:35e:7d21:cad2 with SMTP id ffacd0b85a97d-35efed5a649mr1974916f8f.30.1717756849835; Fri, 07 Jun 2024 03:40:49 -0700 (PDT) Received: from localhost.localdomain ([78.210.52.100]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-35ef5d297a4sm3731717f8f.9.2024.06.07.03.40.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 07 Jun 2024 03:40:49 -0700 (PDT) From: Antoni Pokusinski X-Google-Original-From: Antoni Pokusinski To: jic23@kernel.org Cc: linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org, apokusinski@o2.pl Subject: [PATCH v2] iio: humidity: si7020: add heater support Date: Fri, 7 Jun 2024 12:39:45 +0200 Message-Id: <20240607103944.11730-1-apokusinski@o2.pl> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: linux-iio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 This patch adds support for the integrated on-chip heater that is present on all the devices supported by this driver (si7020, si7021, si7013, th6). In order to configure the heater, the driver interacts with the following device registers: * User Register - the 2nd bit of this register is a "Heater Enable bit" (0 means that the heater is off, 1 means that it's on). * Heater Register - this register is present only on the si70xx devices and controls the current flowing through the heater. The 4 lower bits of this register can be assigned values from 0x0 to 0xF. Signed-off-by: Antoni Pokusinski Signed-off-by: Antoni Pokusinski --- Changes since v1: * macros: remove unnecessary comments * macros: add more meaningful names * `struct si7020_data`: add comment explaining the mutex * `si7020_update_reg()`: change the control flow to more standard * use `scoped_guard()` instead of `mutex_lock() <...> mutex_unlock()` * `si7020_probe()`: add comment for User Register default value * minor format fixes --- drivers/iio/humidity/si7020.c | 137 +++++++++++++++++++++++++++++++++- 1 file changed, 133 insertions(+), 4 deletions(-) diff --git a/drivers/iio/humidity/si7020.c b/drivers/iio/humidity/si7020.c index fb1006649328..1215fab7b1a5 100644 --- a/drivers/iio/humidity/si7020.c +++ b/drivers/iio/humidity/si7020.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include @@ -33,17 +34,38 @@ #define SI7020CMD_TEMP_HOLD 0xE3 /* Software Reset */ #define SI7020CMD_RESET 0xFE +#define SI7020CMD_USR_WRITE 0xE6 +/* "Heater Enabled" bit in the User Register */ +#define SI7020_USR_HEATER_EN BIT(2) +#define SI7020CMD_HEATER_WRITE 0x51 +/* Heater current configuration bits */ +#define SI7020_HEATER_VAL GENMASK(3, 0) + +struct si7020_data { + struct i2c_client *client; + /* Lock for cached register values */ + struct mutex lock; + u8 user_reg; + u8 heater_reg; +}; + +static const int si7020_heater_vals[] = { 0, 1, 0xF }; static int si7020_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { - struct i2c_client **client = iio_priv(indio_dev); + struct si7020_data *data = iio_priv(indio_dev); int ret; switch (mask) { case IIO_CHAN_INFO_RAW: - ret = i2c_smbus_read_word_swapped(*client, + if (chan->type == IIO_CURRENT) { + *val = data->heater_reg; + return IIO_VAL_INT; + } + + ret = i2c_smbus_read_word_swapped(data->client, chan->type == IIO_TEMP ? SI7020CMD_TEMP_HOLD : SI7020CMD_RH_HOLD); @@ -96,17 +118,118 @@ static const struct iio_chan_spec si7020_channels[] = { .type = IIO_TEMP, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_OFFSET), + }, + { + .type = IIO_CURRENT, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW), + .extend_name = "heater", + } +}; + +static int si7020_update_reg(struct si7020_data *data, + u8 *reg, u8 cmd, u8 mask, u8 val) +{ + u8 new = (*reg & ~mask) | val; + int ret; + + ret = i2c_smbus_write_byte_data(data->client, cmd, new); + if (ret) + return ret; + + *reg = new; + + return 0; +} + +static int si7020_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct si7020_data *data = iio_priv(indio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + if (chan->type != IIO_CURRENT || val2 != 0 || + val < si7020_heater_vals[0] || val > si7020_heater_vals[2]) + return -EINVAL; + + scoped_guard(mutex, &data->lock) + ret = si7020_update_reg(data, &data->heater_reg, + SI7020CMD_HEATER_WRITE, SI7020_HEATER_VAL, val); + return ret; + default: + return -EINVAL; } +} + +static int si7020_read_available(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + const int **vals, + int *type, int *length, long mask) +{ + if (mask != IIO_CHAN_INFO_RAW || chan->type != IIO_CURRENT) + return -EINVAL; + + *vals = si7020_heater_vals; + *type = IIO_VAL_INT; + + return IIO_AVAIL_RANGE; +} + +static ssize_t si7020_show_heater_en(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct iio_dev *indio_dev = dev_to_iio_dev(dev); + struct si7020_data *data = iio_priv(indio_dev); + + return sysfs_emit(buf, "%d\n", !!(data->user_reg & SI7020_USR_HEATER_EN)); +} + +static ssize_t si7020_store_heater_en(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct iio_dev *indio_dev = dev_to_iio_dev(dev); + struct si7020_data *data = iio_priv(indio_dev); + int ret; + bool val; + + ret = kstrtobool(buf, &val); + if (ret) + return ret; + + scoped_guard(mutex, &data->lock) + ret = si7020_update_reg(data, &data->user_reg, SI7020CMD_USR_WRITE, + SI7020_USR_HEATER_EN, val ? SI7020_USR_HEATER_EN : 0); + + return ret < 0 ? ret : len; +} + +static IIO_DEVICE_ATTR(heater_enable, 0644, + si7020_show_heater_en, si7020_store_heater_en, 0); + +static struct attribute *si7020_attributes[] = { + &iio_dev_attr_heater_enable.dev_attr.attr, + NULL +}; + +static const struct attribute_group si7020_attribute_group = { + .attrs = si7020_attributes, }; static const struct iio_info si7020_info = { .read_raw = si7020_read_raw, + .write_raw = si7020_write_raw, + .read_avail = si7020_read_available, + .attrs = &si7020_attribute_group, }; static int si7020_probe(struct i2c_client *client) { struct iio_dev *indio_dev; - struct i2c_client **data; + struct si7020_data *data; int ret; if (!i2c_check_functionality(client->adapter, @@ -126,7 +249,9 @@ static int si7020_probe(struct i2c_client *client) return -ENOMEM; data = iio_priv(indio_dev); - *data = client; + i2c_set_clientdata(client, indio_dev); + data->client = client; + mutex_init(&data->lock); indio_dev->name = dev_name(&client->dev); indio_dev->modes = INDIO_DIRECT_MODE; @@ -134,6 +259,10 @@ static int si7020_probe(struct i2c_client *client) indio_dev->channels = si7020_channels; indio_dev->num_channels = ARRAY_SIZE(si7020_channels); + /* All the "reserved" bits in the User Register are 1s by default */ + data->user_reg = 0x3A; + data->heater_reg = 0x0; + return devm_iio_device_register(&client->dev, indio_dev); }