From patchwork Fri Apr 12 09:15:37 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gregory CLEMENT X-Patchwork-Id: 10897665 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 39BB31669 for ; Fri, 12 Apr 2019 09:16:25 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 136C428E53 for ; Fri, 12 Apr 2019 09:16:25 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0309E28E5D; Fri, 12 Apr 2019 09:16:25 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 6FCAC28E53 for ; Fri, 12 Apr 2019 09:16:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=uVpHhKYUhhGgjO4jvZDRAtE0g2zITzZ3mtXS5PcJ1Eo=; b=lMSXC1ekLBDp5N A0ADb7gSQ9b9wEeyFm8pYoT4QwI7Txwf67oUsQ2jPeqs13YbH0N/QvjwkzXXedLAQRVih0AqcpAbv lKn3LF8InV2Ctfw8BFH7LORanay6gY327fh5kpwECJBMGsKR6U2Wp7GnWK1ykD9sqYUhQbAfD4GNI EM47D/wzseKi9Z8hUB1g/akGo4CAxJBlTRTTrXZR7B2Iop2/IJZ4xTe6kBVCyyim1g4HGrwSDYDyi Pq+KH92st/BJ5LXs4KbGM04sxVqZxYH3YieN4gO08rmnmPlVDmTzl22qXD/x0f9UQ53OyKXMeRUys mrSm1ZOLPQ36j/IQaJhg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hEsIE-000113-0Z; Fri, 12 Apr 2019 09:16:18 +0000 Received: from relay6-d.mail.gandi.net ([217.70.183.198]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hEsHt-0000e6-DB for linux-arm-kernel@lists.infradead.org; Fri, 12 Apr 2019 09:15:59 +0000 X-Originating-IP: 87.231.134.186 Received: from localhost (87-231-134-186.rev.numericable.fr [87.231.134.186]) (Authenticated sender: gregory.clement@bootlin.com) by relay6-d.mail.gandi.net (Postfix) with ESMTPSA id 38586C0002; Fri, 12 Apr 2019 09:15:48 +0000 (UTC) From: Gregory CLEMENT To: Jonathan Cameron , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , linux-iio@vger.kernel.org Subject: [PATCH v3 2/2] iio: adc: Add driver for the TI ADS8344 A/DC chips Date: Fri, 12 Apr 2019 11:15:37 +0200 Message-Id: <20190412091537.14657-3-gregory.clement@bootlin.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190412091537.14657-1-gregory.clement@bootlin.com> References: <20190412091537.14657-1-gregory.clement@bootlin.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190412_021557_751247_F655C695 X-CRM114-Status: GOOD ( 15.81 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devicetree@vger.kernel.org, Alexandre Belloni , Gregory CLEMENT , Rob Herring , Thomas Petazzoni , linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP This adds support for the Texas Instruments ADS8344 ADC chip. This chip has a 16-bit 8-Channel ADC and is access directly through SPI. Signed-off-by: Gregory CLEMENT --- drivers/iio/adc/Kconfig | 10 ++ drivers/iio/adc/Makefile | 1 + drivers/iio/adc/ti-ads8344.c | 204 +++++++++++++++++++++++++++++++++++ 3 files changed, 215 insertions(+) create mode 100644 drivers/iio/adc/ti-ads8344.c diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 76db6e5cc296..447d3a871746 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -967,6 +967,16 @@ config TI_ADS7950 To compile this driver as a module, choose M here: the module will be called ti-ads7950. +config TI_ADS8344 + tristate "Texas Instruments ADS8344" + depends on SPI && OF + help + If you say yes here you get support for Texas Instruments ADS8344 + ADC chips + + This driver can also be built as a module. If so, the module will be + called ti-ads8344. + config TI_ADS8688 tristate "Texas Instruments ADS8688" depends on SPI && OF diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index 6fcebd167524..1f3ae934111d 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -87,6 +87,7 @@ obj-$(CONFIG_TI_ADC128S052) += ti-adc128s052.o obj-$(CONFIG_TI_ADC161S626) += ti-adc161s626.o obj-$(CONFIG_TI_ADS1015) += ti-ads1015.o obj-$(CONFIG_TI_ADS7950) += ti-ads7950.o +obj-$(CONFIG_TI_ADS8344) += ti-ads8344.o obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o obj-$(CONFIG_TI_ADS124S08) += ti-ads124s08.o obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o diff --git a/drivers/iio/adc/ti-ads8344.c b/drivers/iio/adc/ti-ads8344.c new file mode 100644 index 000000000000..e1649e237edc --- /dev/null +++ b/drivers/iio/adc/ti-ads8344.c @@ -0,0 +1,204 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * ADS8344 16-bit 8-Channel ADC driver + * + * Author: Gregory CLEMENT + * + * Datasheet: http://www.ti.com/lit/ds/symlink/ads8344.pdf + */ + +#include +#include +#include +#include +#include +#include + +#define ADS8344_START BIT(7) +#define ADS8344_SINGLE_END BIT(2) +#define ADS8344_CHANNEL(channel) ((channel) << 4) +#define ADS8344_CLOCK_INTERNAL 0x2 /* PD1 = 1 and PD0 = 0 */ + +struct ads8344 { + struct spi_device *spi; + struct regulator *reg; + /* + * Lock protecting access to adc->tx_buff and rx_buff, + * especially from concurrent read on sysfs file. + */ + struct mutex lock; + + u8 tx_buf ____cacheline_aligned; + u16 rx_buf; +}; + +#define ADS8344_VOLTAGE_CHANNEL(chan, si) \ + { \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .channel = chan, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ + } + +#define ADS8344_VOLTAGE_CHANNEL_DIFF(chan1, chan2, si) \ + { \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .channel = (chan1), \ + .channel2 = (chan2), \ + .differential = 1, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ + } + +static const struct iio_chan_spec ads8344_channels[] = { + ADS8344_VOLTAGE_CHANNEL(0, 0), + ADS8344_VOLTAGE_CHANNEL(1, 4), + ADS8344_VOLTAGE_CHANNEL(2, 1), + ADS8344_VOLTAGE_CHANNEL(3, 5), + ADS8344_VOLTAGE_CHANNEL(4, 2), + ADS8344_VOLTAGE_CHANNEL(5, 6), + ADS8344_VOLTAGE_CHANNEL(6, 3), + ADS8344_VOLTAGE_CHANNEL(7, 7), + ADS8344_VOLTAGE_CHANNEL_DIFF(0, 1, 8), + ADS8344_VOLTAGE_CHANNEL_DIFF(2, 3, 9), + ADS8344_VOLTAGE_CHANNEL_DIFF(4, 5, 10), + ADS8344_VOLTAGE_CHANNEL_DIFF(6, 7, 11), + ADS8344_VOLTAGE_CHANNEL_DIFF(1, 0, 12), + ADS8344_VOLTAGE_CHANNEL_DIFF(3, 2, 13), + ADS8344_VOLTAGE_CHANNEL_DIFF(5, 4, 14), + ADS8344_VOLTAGE_CHANNEL_DIFF(7, 6, 15), +}; + +static int ads8344_adc_conversion(struct ads8344 *adc, int channel, + bool differential) +{ + struct spi_device *spi = adc->spi; + int ret; + + adc->tx_buf = ADS8344_START; + if (!differential) + adc->tx_buf |= ADS8344_SINGLE_END; + adc->tx_buf |= ADS8344_CHANNEL(channel); + adc->tx_buf |= ADS8344_CLOCK_INTERNAL; + + ret = spi_write(spi, &adc->tx_buf, 1); + if (ret) + return ret; + + udelay(9); + + ret = spi_read(spi, &adc->rx_buf, 2); + if (ret) + return ret; + + return adc->rx_buf; +} + +static int ads8344_read_raw(struct iio_dev *iio, + struct iio_chan_spec const *channel, int *value, + int *shift, long mask) +{ + struct ads8344 *adc = iio_priv(iio); + + switch (mask) { + case IIO_CHAN_INFO_RAW: + mutex_lock(&adc->lock); + *value = ads8344_adc_conversion(adc, channel->scan_index, + channel->differential); + mutex_unlock(&adc->lock); + if (*value < 0) + return *value; + + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + *value = regulator_get_voltage(adc->reg); + if (*value < 0) + return *value; + + /* convert regulator output voltage to mV */ + *value /= 1000; + *shift = 16; + + return IIO_VAL_FRACTIONAL_LOG2; + default: + return -EINVAL; + } +} + +static const struct iio_info ads8344_info = { + .read_raw = ads8344_read_raw, +}; + +static int ads8344_probe(struct spi_device *spi) +{ + struct iio_dev *indio_dev; + struct ads8344 *adc; + int ret; + + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc)); + if (!indio_dev) + return -ENOMEM; + + adc = iio_priv(indio_dev); + adc->spi = spi; + mutex_init(&adc->lock); + + indio_dev->name = dev_name(&spi->dev); + indio_dev->dev.parent = &spi->dev; + indio_dev->dev.of_node = spi->dev.of_node; + indio_dev->info = &ads8344_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = ads8344_channels; + indio_dev->num_channels = ARRAY_SIZE(ads8344_channels); + + adc->reg = devm_regulator_get(&spi->dev, "vref"); + if (IS_ERR(adc->reg)) + return PTR_ERR(adc->reg); + + ret = regulator_enable(adc->reg); + if (ret) + return ret; + + spi_set_drvdata(spi, indio_dev); + + ret = iio_device_register(indio_dev); + if (ret) { + regulator_disable(adc->reg); + return ret; + } + + return 0; +} + +static int ads8344_remove(struct spi_device *spi) +{ + struct iio_dev *indio_dev = spi_get_drvdata(spi); + struct ads8344 *adc = iio_priv(indio_dev); + + iio_device_unregister(indio_dev); + regulator_disable(adc->reg); + + return 0; +} + +static const struct of_device_id ads8344_of_match[] = { + { .compatible = "ti,ads8344", }, + {} +}; +MODULE_DEVICE_TABLE(of, ads8344_dt_ids); + +static struct spi_driver ads8344_driver = { + .driver = { + .name = "ads8344", + .of_match_table = ads8344_of_match, + }, + .probe = ads8344_probe, + .remove = ads8344_remove, +}; +module_spi_driver(ads8344_driver); + +MODULE_AUTHOR("Gregory CLEMENT "); +MODULE_DESCRIPTION("ADS8344 driver"); +MODULE_LICENSE("GPL");