From patchwork Wed Apr 1 18:51:37 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandru Lazar X-Patchwork-Id: 11469443 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6C40A912 for ; Wed, 1 Apr 2020 18:46:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 49E76206F5 for ; Wed, 1 Apr 2020 18:46:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=startmail.com header.i=@startmail.com header.b="whLXAyiH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732208AbgDASqt (ORCPT ); Wed, 1 Apr 2020 14:46:49 -0400 Received: from mx-out2.startmail.com ([145.131.90.155]:49903 "EHLO mx-out2.startmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726640AbgDASqt (ORCPT ); Wed, 1 Apr 2020 14:46:49 -0400 From: Alexandru Lazar DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=startmail.com; s=2017-11; t=1585766807; bh=7fnFSy+sEmwQpklZYylFDBkgyCMloNhpV7NmOpPWkAY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=whLXAyiHNDHwPSzi9O+7bAJmkyCevmqk5rFFGKmrxx9HuNlTZFGroeLW1cux6uf2o Jz0IkiFZyL/sRxTXLkXMp42kaw+X7iZR2lC7znzL/H8cdtDJHOBB2pzhXvjdhFiJdZ 8nkn1PlQmxqDFPagVoNsQhKRzXZeAjsku3vCLLJdQhvQNi//VoktKp5eyVxeHPLecN e0rUq31+8xLbGui75E0BFDdk06mbbUesuZFIevPXfHXDWhAYAzEm7tN8HVfkk4l4NF ZI1m4Yka7Zv6Koc+WQz5vJEPHUYP6B5+YECOZtr3c/pXrfZAro8Iti12i2wo550qcQ RUXLMoDJ/tAGg== To: linux-iio@vger.kernel.org Cc: devicetree@vger.kernel.org, jic23@kernel.org, knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net, robh+dt@kernel.org, mark.rutland@arm.com, Alexandru Lazar Subject: [PATCH v6 1/2] dt-bindings: iio: adc: Add MAX1241 bindings Date: Wed, 1 Apr 2020 21:51:37 +0300 Message-Id: <20200401185138.10673-2-alazar@startmail.com> In-Reply-To: <20200401185138.10673-1-alazar@startmail.com> References: <20200401185138.10673-1-alazar@startmail.com> MIME-Version: 1.0 Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org Add device-tree bindings documentation for the MAX1241 device driver. Signed-off-by: Alexandru Lazar --- .../bindings/iio/adc/maxim,max1241.yaml | 64 +++++++++++++++++++ 1 file changed, 64 insertions(+) create mode 100644 Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml diff --git a/Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml b/Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml new file mode 100644 index 000000000000..7da9e4153ac1 --- /dev/null +++ b/Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml @@ -0,0 +1,64 @@ +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) +# Copyright 2020 Alexandru Lazar +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/iio/adc/maxim,max1241.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Maxim MAX1241 12-bit, single-channel analog to digital converter + +maintainers: + - Alexandru Lazar + +description: | + Bindings for the max1241 12-bit, single-channel ADC device. Datasheet + can be found at: + https://datasheets.maximintegrated.com/en/ds/MAX1240-MAX1241.pdf + +properties: + compatible: + enum: + - maxim,max1241 + + reg: + maxItems: 1 + + vdd-supply: + description: + Device tree identifier of the regulator that powers the ADC. + + vref-supply: + description: + Device tree identifier of the regulator that provides the external + reference voltage. + maxItems: 1 + + shutdown-gpios: + description: + GPIO spec for the GPIO pin connected to the ADC's /SHDN pin. If + specified, the /SHDN pin will be asserted between conversions, + thus enabling power-down mode. + maxItems: 1 + +required: + - compatible + - reg + - vdd-supply + - vref-supply + +examples: + - | + #include + spi { + #address-cells = <1>; + #size-cells = <0>; + + adc@0 { + compatible = "maxim,max1241"; + reg = <0>; + vdd-supply = <&adc_vdd>; + vref-supply = <&adc_vref>; + spi-max-frequency = <1000000>; + shutdown-gpios = <&gpio 26 1>; + }; + }; From patchwork Wed Apr 1 18:51:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandru Lazar X-Patchwork-Id: 11469445 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2B87592C for ; Wed, 1 Apr 2020 18:46:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F137B2082F for ; Wed, 1 Apr 2020 18:46:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=startmail.com header.i=@startmail.com header.b="S2esmc+V" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732214AbgDASqw (ORCPT ); Wed, 1 Apr 2020 14:46:52 -0400 Received: from mx-out2.startmail.com ([145.131.90.155]:55428 "EHLO mx-out2.startmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732211AbgDASqw (ORCPT ); Wed, 1 Apr 2020 14:46:52 -0400 From: Alexandru Lazar DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=startmail.com; s=2017-11; t=1585766809; bh=+637+Z/mx+woFC6bMaMRSAys7GdZNj8mmMIwwyL8tpc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=S2esmc+VbcTrQfueectXsW3MczkJXr/rwIdDoXwWRQmoZSUPLa8nk46C4Av/+DcBq BFdPjBnVxasnn64zwmXWtBp9wyKSVikDb83kgWB//woAJfKXO13DIHeqR/g+LAWB5Q 3N2ScQsO/WDszIq4yVfYPrnQ0QLhhClCI56gi+4end9lskt2oNw7ERN1hr93/ELBFP cvL0hNEHk44ji+ssy/kg0NOVyyjFQHVObO4SLRa8200b9VpG24YeC1PK3+I6ZL+QHV PWawfZgcQFS5AbSkRoZfv1nYKpVoYMyguEVNhhsHH5cZaMaiuBXQfxn24ACDTsiXyg /CJfPKmk9waEw== To: linux-iio@vger.kernel.org Cc: devicetree@vger.kernel.org, jic23@kernel.org, knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net, robh+dt@kernel.org, mark.rutland@arm.com, Alexandru Lazar , Alexandru Ardelean Subject: [PATCH v6 2/2] iio: adc: Add MAX1241 driver Date: Wed, 1 Apr 2020 21:51:38 +0300 Message-Id: <20200401185138.10673-3-alazar@startmail.com> In-Reply-To: <20200401185138.10673-1-alazar@startmail.com> References: <20200401185138.10673-1-alazar@startmail.com> MIME-Version: 1.0 Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org Add driver for the Maxim MAX1241 12-bit, single-channel ADC. Reviewed-by: Alexandru Ardelean Signed-off-by: Alexandru Lazar --- drivers/iio/adc/Kconfig | 10 ++ drivers/iio/adc/Makefile | 1 + drivers/iio/adc/max1241.c | 227 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 238 insertions(+) create mode 100644 drivers/iio/adc/max1241.c diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 5d8540b7b427..55f6462cd93f 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -566,6 +566,16 @@ config MAX1118 To compile this driver as a module, choose M here: the module will be called max1118. +config MAX1241 + tristate "Maxim max1241 ADC driver" + depends on SPI_MASTER + help + Say yes here to build support for Maxim max1241 12-bit, single-channel + ADC. + + To compile this driver as a module, choose M here: the module will be + called max1241. + config MAX1363 tristate "Maxim max1363 ADC driver" depends on I2C diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index a1f1fbec0f87..37d6f17559dc 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -54,6 +54,7 @@ obj-$(CONFIG_LTC2497) += ltc2497.o obj-$(CONFIG_MAX1027) += max1027.o obj-$(CONFIG_MAX11100) += max11100.o obj-$(CONFIG_MAX1118) += max1118.o +obj-$(CONFIG_MAX1241) += max1241.o obj-$(CONFIG_MAX1363) += max1363.o obj-$(CONFIG_MAX9611) += max9611.o obj-$(CONFIG_MCP320X) += mcp320x.o diff --git a/drivers/iio/adc/max1241.c b/drivers/iio/adc/max1241.c new file mode 100644 index 000000000000..541939c7abca --- /dev/null +++ b/drivers/iio/adc/max1241.c @@ -0,0 +1,227 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * MAX1241 low-power, 12-bit serial ADC + * + * Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX1240-MAX1241.pdf + */ + +#include +#include +#include +#include +#include +#include + +#define MAX1241_VAL_MASK GENMASK(11, 0) +#define MAX1241_SHUTDOWN_DELAY_USEC 4 + +enum max1241_id { + max1241, +}; + +struct max1241 { + struct spi_device *spi; + struct mutex lock; + struct regulator *vdd; + struct regulator *vref; + struct gpio_desc *shutdown; + + __be16 data ____cacheline_aligned; +}; + +static const struct iio_chan_spec max1241_channels[] = { + { + .type = IIO_VOLTAGE, + .indexed = 1, + .channel = 0, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + }, +}; + +static int max1241_read(struct max1241 *adc) +{ + struct spi_transfer xfers[] = { + /* + * Begin conversion by bringing /CS low for at least + * tconv us. + */ + { + .len = 0, + .delay.value = 8, + .delay.unit = SPI_DELAY_UNIT_USECS, + }, + /* + * Then read two bytes of data in our RX buffer. + */ + { + .rx_buf = &adc->data, + .len = 2, + }, + }; + + return spi_sync_transfer(adc->spi, xfers, ARRAY_SIZE(xfers)); +} + +static int max1241_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + int ret, vref_uV; + struct max1241 *adc = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_RAW: + mutex_lock(&adc->lock); + + if (adc->shutdown) { + gpiod_set_value(adc->shutdown, 0); + udelay(MAX1241_SHUTDOWN_DELAY_USEC); + ret = max1241_read(adc); + gpiod_set_value(adc->shutdown, 1); + } else + ret = max1241_read(adc); + + if (ret) { + mutex_unlock(&adc->lock); + return ret; + } + + *val = (be16_to_cpu(adc->data) >> 3) & MAX1241_VAL_MASK; + + mutex_unlock(&adc->lock); + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + vref_uV = regulator_get_voltage(adc->vref); + + if (vref_uV < 0) + return vref_uV; + + *val = vref_uV / 1000; + *val2 = 12; + + return IIO_VAL_FRACTIONAL_LOG2; + default: + return -EINVAL; + } +} + +static const struct iio_info max1241_info = { + .read_raw = max1241_read_raw, +}; + +static void max1241_disable_vdd_action(void *data) +{ + struct max1241 *adc = data; + struct device *dev = &adc->spi->dev; + int err; + + err = regulator_disable(adc->vdd); + if (err) + dev_err(dev, "could not disable vdd regulator.\n"); +} + +static void max1241_disable_vref_action(void *data) +{ + struct max1241 *adc = data; + struct device *dev = &adc->spi->dev; + int err; + + err = regulator_disable(adc->vref); + if (err) + dev_err(dev, "could not disable vref regulator.\n"); +} + +static int max1241_probe(struct spi_device *spi) +{ + struct device *dev = &spi->dev; + struct iio_dev *indio_dev; + struct max1241 *adc; + int ret; + + indio_dev = devm_iio_device_alloc(dev, sizeof(*adc)); + if (!indio_dev) + return -ENOMEM; + + adc = iio_priv(indio_dev); + adc->spi = spi; + mutex_init(&adc->lock); + + spi_set_drvdata(spi, indio_dev); + + adc->vdd = devm_regulator_get(dev, "vdd"); + if (IS_ERR(adc->vdd)) { + dev_err(dev, "failed to get vdd regulator\n"); + return PTR_ERR(adc->vdd); + } + + ret = regulator_enable(adc->vdd); + if (ret) + return ret; + + ret = devm_add_action_or_reset(dev, max1241_disable_vdd_action, adc); + if (ret) { + dev_err(dev, "could not set up vdd regulator cleanup action\n"); + return ret; + } + + adc->vref = devm_regulator_get(dev, "vref"); + if (IS_ERR(adc->vref)) { + dev_err(dev, "failed to get vref regulator\n"); + return PTR_ERR(adc->vref); + } + + ret = regulator_enable(adc->vref); + if (ret) + return ret; + + ret = devm_add_action_or_reset(dev, max1241_disable_vref_action, adc); + if (ret) { + dev_err(dev, "could not set up vref regulator cleanup action\n"); + return ret; + } + + adc->shutdown = devm_gpiod_get_optional(dev, "shutdown", + GPIOD_OUT_HIGH); + if (IS_ERR(adc->shutdown)) + return PTR_ERR(adc->shutdown); + + if (adc->shutdown) + dev_dbg(dev, "shutdown pin passed, low-power mode enabled"); + else + dev_dbg(dev, "no shutdown pin passed, low-power mode disabled"); + + indio_dev->name = spi_get_device_id(spi)->name; + indio_dev->dev.parent = dev; + indio_dev->info = &max1241_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = max1241_channels; + indio_dev->num_channels = ARRAY_SIZE(max1241_channels); + + return devm_iio_device_register(dev, indio_dev); +} + +static const struct spi_device_id max1241_id[] = { + { "max1241", max1241 }, + {} +}; + +static const struct of_device_id max1241_dt_ids[] = { + { .compatible = "maxim,max1241" }, + {} +}; +MODULE_DEVICE_TABLE(of, max1241_dt_ids); + +static struct spi_driver max1241_spi_driver = { + .driver = { + .name = "max1241", + .of_match_table = max1241_dt_ids, + }, + .probe = max1241_probe, + .id_table = max1241_id, +}; +module_spi_driver(max1241_spi_driver); + +MODULE_AUTHOR("Alexandru Lazar "); +MODULE_DESCRIPTION("MAX1241 ADC driver"); +MODULE_LICENSE("GPL v2");