From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELuKCofwG+hqVJVq7gPL6OQfZkiImeE/1KPfQ0xWy2WdjyKQiNfyjnbn5U2vxXP7A7qyggnC ARC-Seal: i=1; a=rsa-sha256; t=1521478994; cv=none; d=google.com; s=arc-20160816; b=YOlCEe2xGCn0CQxzFkjMJjI3jE9IAV/+yVBnS/5LqNORL1+N5zezC6Bpv1SPvGJ2Zu WH+4uUV2BDBXNaFO5HtR2QxFv9vWELvVylA0gP0UsaeDVH8P/GpQ0FvgpRaCkKEg6KtQ ahUl0wZEp44+TglOOHu2yCXkCSuGJQWV5UcpCmwH7LXLTVVR4zpBbdPh3EZRK/09sfbY W4/MUxc0EEeXVKbiwY8QViDu0KZg2wbYzljUicA1rxKUUewD9Bq/szpWzXLlRCGetebf iTrCbrYPP0rJm1uJJA9FT4m3733d761A/e25HG+hUJpM04tJEsiJO6Ws14ylXr6N9wVk J9NA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=spamdiagnosticmetadata:spamdiagnosticoutput:mime-version:references :in-reply-to:message-id:date:subject:cc:to:from:dkim-signature :arc-authentication-results; bh=mkVsZJ50gqnNr1/Ylv9aQva6QzAumixwu73Le0vM3wo=; b=KJmgYxkxUOI5E0Y2UfKQH4awbtmg/nLqTpnf40el+EGDbs1lxJq3OrXERv/XsRUz4p pmSFAdf23LGxObL3X8kfb2CUaZfnV/3nRib8PiP6eAHMloTC4q0tiI9Yz5Rjq01k6KNe 57PQ3eHBa1ZecDktzgxm7W2wEfbkvGisVpmO9/h8glRGSLEO2iWFwLeJKDCK/1+wMB6g PaSmL4dPhC7fqSgNKH6Rt7xLBlX3T1i4BPFgoOohh9MJLNpoo1dNYSeg1h+ctV/seuoi kkRzkSeup0wlIzNmYQdYAWw7LJpsBSbQa/J71V+HmTXipKLZlRR7dOphXt3cErDM4/NE s5UQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@axentia.se header.s=selector1 header.b=rVPPKb0A; spf=pass (google.com: domain of peda@axentia.se designates 40.107.4.120 as permitted sender) smtp.mailfrom=peda@axentia.se Authentication-Results: mx.google.com; dkim=pass header.i=@axentia.se header.s=selector1 header.b=rVPPKb0A; spf=pass (google.com: domain of peda@axentia.se designates 40.107.4.120 as permitted sender) smtp.mailfrom=peda@axentia.se Authentication-Results: spf=none (sender IP is ) smtp.mailfrom=peda@axentia.se; From: Peter Rosin To: linux-kernel@vger.kernel.org Cc: Peter Rosin , Jonathan Cameron , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , Rob Herring , Mark Rutland , "David S. Miller" , Mauro Carvalho Chehab , Greg Kroah-Hartman , Linus Walleij , Randy Dunlap , linux-iio@vger.kernel.org, devicetree@vger.kernel.org Subject: [PATCH 3/3] iio: wrapper: unit-converter: new driver Date: Mon, 19 Mar 2018 18:02:46 +0100 Message-Id: <20180319170246.26830-4-peda@axentia.se> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20180319170246.26830-1-peda@axentia.se> References: <20180319170246.26830-1-peda@axentia.se> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [85.226.244.23] X-ClientProxiedBy: HE1P190CA0048.EURP190.PROD.OUTLOOK.COM (2603:10a6:7:52::37) To AM4PR0202MB2769.eurprd02.prod.outlook.com (2603:10a6:200:8c::19) X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 4140a4d2-5167-40cb-6f16-08d58dbb4c06 X-Microsoft-Antispam: UriScan:;BCL:0;PCL:0;RULEID:(7020095)(4652020)(7021125)(5600026)(4604075)(4534165)(7022125)(4603075)(4627221)(201702281549075)(7048125)(7024125)(7027125)(7028125)(7023125)(2017052603328)(7153060)(7193020);SRVR:AM4PR0202MB2769; 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E.g. if the full voltage it too big for the ADC to handle. Likewise, if an ADC channel measures the voltage across a resistor, the interesting value is often the current through the resistor. This driver solves both problems by allowing to linearly scale a channel and by allowing changes to the type of the channel. Or both. Signed-off-by: Peter Rosin --- MAINTAINERS | 1 + drivers/iio/wrapper/Kconfig | 9 ++ drivers/iio/wrapper/Makefile | 1 + drivers/iio/wrapper/iio-unit-converter.c | 268 +++++++++++++++++++++++++++++++ 4 files changed, 279 insertions(+) create mode 100644 drivers/iio/wrapper/iio-unit-converter.c diff --git a/MAINTAINERS b/MAINTAINERS index 5dd555c7b1b0..b879289f1318 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -6889,6 +6889,7 @@ M: Peter Rosin L: linux-iio@vger.kernel.org S: Maintained F: Documentation/devicetree/bindings/iio/wrapper/io-channel-unit-converter.txt +F: drivers/iio/wrapper/iio-unit-converter.c IKANOS/ADI EAGLE ADSL USB DRIVER M: Matthieu Castet diff --git a/drivers/iio/wrapper/Kconfig b/drivers/iio/wrapper/Kconfig index f27de347c9b3..16554479264a 100644 --- a/drivers/iio/wrapper/Kconfig +++ b/drivers/iio/wrapper/Kconfig @@ -15,4 +15,13 @@ config IIO_MUX To compile this driver as a module, choose M here: the module will be called iio-mux. +config IIO_UNIT_CONVERTER + tristate "IIO unit converter" + depends on OF || COMPILE_TEST + help + Say yes here to build support for the IIO unit converter. + + To compile this driver as a module, choose M here: the + module will be called iio-unit-converter. + endmenu diff --git a/drivers/iio/wrapper/Makefile b/drivers/iio/wrapper/Makefile index 53a7b78734e3..1b9db53bd420 100644 --- a/drivers/iio/wrapper/Makefile +++ b/drivers/iio/wrapper/Makefile @@ -4,3 +4,4 @@ # When adding new entries keep the list in alphabetical order obj-$(CONFIG_IIO_MUX) += iio-mux.o +obj-$(CONFIG_IIO_UNIT_CONVERTER) += iio-unit-converter.o diff --git a/drivers/iio/wrapper/iio-unit-converter.c b/drivers/iio/wrapper/iio-unit-converter.c new file mode 100644 index 000000000000..53c126f39e4e --- /dev/null +++ b/drivers/iio/wrapper/iio-unit-converter.c @@ -0,0 +1,268 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * IIO unit converter + * + * Copyright (C) 2018 Axentia Technologies AB + * + * Author: Peter Rosin + */ + +#include +#include +#include +#include +#include +#include +#include + +struct unit_converter { + struct iio_channel *parent; + struct iio_dev *indio_dev; + struct iio_chan_spec chan; + struct iio_chan_spec_ext_info *ext_info; + s32 numerator; + s32 denominator; +}; + +static int unit_converter_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct unit_converter *uc = iio_priv(indio_dev); + unsigned long long tmp; + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + return iio_read_channel_raw(uc->parent, val); + + case IIO_CHAN_INFO_SCALE: + ret = iio_read_channel_scale(uc->parent, val, val2); + switch (ret) { + case IIO_VAL_FRACTIONAL: + *val *= uc->numerator; + *val2 *= uc->denominator; + return ret; + case IIO_VAL_INT: + *val *= uc->numerator; + if (uc->denominator == 1) + return ret; + *val2 = uc->denominator; + return IIO_VAL_FRACTIONAL; + case IIO_VAL_FRACTIONAL_LOG2: + tmp = *val * 1000000000LL; + do_div(tmp, uc->denominator); + tmp *= uc->numerator; + do_div(tmp, 1000000000LL); + *val = tmp; + return ret; + } + return -EOPNOTSUPP; + } + + return -EINVAL; +} + +static int unit_converter_read_avail(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + const int **vals, int *type, int *length, + long mask) +{ + struct unit_converter *uc = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_RAW: + *type = IIO_VAL_INT; + return iio_read_avail_channel_raw(uc->parent, vals, length); + } + + return -EINVAL; +} + +static int unit_converter_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct unit_converter *uc = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_RAW: + return iio_write_channel_raw(uc->parent, val); + } + + return -EINVAL; +} + +static const struct iio_info unit_converter_info = { + .read_raw = unit_converter_read_raw, + .read_avail = unit_converter_read_avail, + .write_raw = unit_converter_write_raw, +}; + +static ssize_t unit_converter_read_ext_info(struct iio_dev *indio_dev, + uintptr_t private, + struct iio_chan_spec const *chan, + char *buf) +{ + struct unit_converter *uc = iio_priv(indio_dev); + + return iio_read_channel_ext_info(uc->parent, + uc->ext_info[private].name, + buf); +} + +static ssize_t unit_converter_write_ext_info(struct iio_dev *indio_dev, + uintptr_t private, + struct iio_chan_spec const *chan, + const char *buf, size_t len) +{ + struct unit_converter *uc = iio_priv(indio_dev); + + return iio_write_channel_ext_info(uc->parent, + uc->ext_info[private].name, + buf, len); +} + +static int unit_converter_configure_channel(struct device *dev, + struct unit_converter *uc, + enum iio_chan_type type) +{ + struct iio_chan_spec *chan = &uc->chan; + struct iio_chan_spec const *pchan = uc->parent->channel; + int ret; + + chan->indexed = 1; + chan->output = pchan->output; + chan->ext_info = uc->ext_info; + + if (type == -1) { + ret = iio_get_channel_type(uc->parent, &type); + if (ret < 0) { + dev_err(dev, "failed to get parent channel type\n"); + return ret; + } + } + chan->type = type; + + if (iio_channel_has_info(pchan, IIO_CHAN_INFO_RAW)) + chan->info_mask_separate |= BIT(IIO_CHAN_INFO_RAW); + if (iio_channel_has_info(pchan, IIO_CHAN_INFO_SCALE)) + chan->info_mask_separate |= BIT(IIO_CHAN_INFO_SCALE); + + if (iio_channel_has_available(pchan, IIO_CHAN_INFO_RAW)) + chan->info_mask_separate_available |= BIT(IIO_CHAN_INFO_RAW); + + chan->channel = 0; + + return 0; +} + +static int unit_converter_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct iio_dev *indio_dev; + struct iio_channel *parent; + struct unit_converter *uc; + const char *type_name; + enum iio_chan_type type = -1; /* default to same as parent */ + int sizeof_ext_info; + int sizeof_priv; + int i; + int ret; + + if (!device_property_read_string(dev, "type", &type_name)) { + if (!strcmp(type_name, "voltage")) + type = IIO_VOLTAGE; + else if (!strcmp(type_name, "current")) + type = IIO_CURRENT; + else + return -EINVAL; + } + + parent = devm_iio_channel_get(dev, "parent"); + if (IS_ERR(parent)) { + if (PTR_ERR(parent) != -EPROBE_DEFER) + dev_err(dev, "failed to get parent channel\n"); + return PTR_ERR(parent); + } + + sizeof_ext_info = iio_get_channel_ext_info_count(parent); + if (sizeof_ext_info) { + sizeof_ext_info += 1; /* one extra entry for the sentinel */ + sizeof_ext_info *= sizeof(*uc->ext_info); + } + + sizeof_priv = sizeof(*uc) + sizeof_ext_info; + + indio_dev = devm_iio_device_alloc(dev, sizeof_priv); + if (!indio_dev) + return -ENOMEM; + + uc = iio_priv(indio_dev); + + uc->numerator = 1; + uc->denominator = 1; + device_property_read_u32(dev, "numerator", &uc->numerator); + device_property_read_u32(dev, "denominator", &uc->denominator); + if (!uc->numerator || !uc->denominator) { + dev_err(dev, "invalid scaling factor.\n"); + return -EINVAL; + } + + platform_set_drvdata(pdev, indio_dev); + + uc->parent = parent; + + indio_dev->name = dev_name(dev); + indio_dev->dev.parent = dev; + indio_dev->info = &unit_converter_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = &uc->chan; + indio_dev->num_channels = 1; + if (sizeof_ext_info) { + uc->ext_info = devm_kmemdup(dev, + parent->channel->ext_info, + sizeof_ext_info, GFP_KERNEL); + if (!uc->ext_info) + return -ENOMEM; + + for (i = 0; uc->ext_info[i].name; ++i) { + if (parent->channel->ext_info[i].read) + uc->ext_info[i].read = unit_converter_read_ext_info; + if (parent->channel->ext_info[i].write) + uc->ext_info[i].write = unit_converter_write_ext_info; + uc->ext_info[i].private = i; + } + } + + ret = unit_converter_configure_channel(dev, uc, type); + if (ret < 0) + return ret; + + ret = devm_iio_device_register(dev, indio_dev); + if (ret) { + dev_err(dev, "failed to register iio device\n"); + return ret; + } + + return 0; +} + +static const struct of_device_id unit_converter_match[] = { + { .compatible = "io-channel-unit-converter" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, unit_converter_match); + +static struct platform_driver unit_converter_driver = { + .probe = unit_converter_probe, + .driver = { + .name = "iio-unit-converter", + .of_match_table = unit_converter_match, + }, +}; +module_platform_driver(unit_converter_driver); + +MODULE_DESCRIPTION("IIO unit converter driver"); +MODULE_AUTHOR("Peter Rosin "); +MODULE_LICENSE("GPL v2"); -- 2.11.0