From patchwork Fri Nov 8 13:56:09 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marcelo Schmitt X-Patchwork-Id: 11234899 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 1AA0D139A for ; Fri, 8 Nov 2019 13:56:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E357A214DB for ; Fri, 8 Nov 2019 13:56:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="UdIr02Tw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728820AbfKHN4Q (ORCPT ); Fri, 8 Nov 2019 08:56:16 -0500 Received: from mail-qk1-f193.google.com ([209.85.222.193]:33263 "EHLO mail-qk1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726650AbfKHN4Q (ORCPT ); Fri, 8 Nov 2019 08:56:16 -0500 Received: by mail-qk1-f193.google.com with SMTP id 71so5346610qkl.0; Fri, 08 Nov 2019 05:56:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=gCAeybLe0NU7m7647n7l4SIquRQF/E2OQ7kqEsPTDCo=; b=UdIr02TwSKfPv7e3SZdwnZqpS81eX5D5cFK3hR/Uq4UgO7WQksLY2taK7FB4KajQnm agMhDj6xHm7g9ihSTvl7hj8GAx7aMCbearL3y0rbavW92GfCo5/biU+tm45l6U1yV3WQ OqmIVF4ItMrdieimGqS/efCPtV9OqKPgjVZ373HNwAR2aPVE1AATihNJo+pzdy0X2ANB z4F7B9w8bFI4xeTRc6f8BfJYkwHiKyFuDFFHPzT/k+7nyjYSjP6cFdHiSjJsjiOtG4Te UJlLDJX0NFWWy5lbD0VgGZ1u2ZoSkvhpzQwRPIsnz0Z+Cd3dGSoMLBrxpAnf8XJykUIk eqMw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=gCAeybLe0NU7m7647n7l4SIquRQF/E2OQ7kqEsPTDCo=; b=dq5ob1wphPCB2GWghWJoinQbQ6v65vTmJFqaa2JFBsGzkV6ClCyqzylTXy5BeJh34j 6bS2+OeqZq2xpDFUPrae6xlANPhlHBoJCif34FNtBSEdguEgjzIjFxH6+5Dm3SCTZA2O RijbFv9JJ4ibKpe9ZEYcCImnxBXKf3uLzPK7lR5wJK3VW3Nfn/UYkzs8BQX9oVGJdd0T M2jhWiSbk9ekbHLpki+6ORQmI8vgx5TFggp3m+KAOuVZXWb+vrw1atjtvDlwnjlfuvUX /oC8wihLxdPS0C2tw89EoPA4k7FIX+8eKNW0uIEd96rodGIFxknsXITjXve9QtNrzdqm oEyg== X-Gm-Message-State: APjAAAWJHyqwCfgZAj1rjl5PjA961lBMaMFJj5sJoJ6YaqnvSNJwrHnJ H1Y0LixNPLtPKLuXAhJM520= X-Google-Smtp-Source: APXvYqwz6uCw0d2ZWvQV7FHEvdst3SlTAX5suY795WniLDYHJ5j5ICzRMoa1G88Pnd4MDGI5CkWjzA== X-Received: by 2002:a37:8b03:: with SMTP id n3mr6571831qkd.493.1573221375073; Fri, 08 Nov 2019 05:56:15 -0800 (PST) Received: from smtp.gmail.com ([2804:d43:422:3955:b4df:7a81:96e1:236e]) by smtp.gmail.com with ESMTPSA id o17sm509058qkg.4.2019.11.08.05.56.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 08 Nov 2019 05:56:14 -0800 (PST) Date: Fri, 8 Nov 2019 10:56:09 -0300 From: Marcelo Schmitt To: jic23@kernel.org, robh@kernel.org Cc: dragos.bogdan@analog.com, alexandru.ardelean@analog.com, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org, devicetree@vger.kernel.org, kernel-usp@googlegroups.com Subject: [PATCH v4 1/2] dt-bindings: iio: adc: Add dt-schema for AD7292 Message-ID: References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180716 Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org Add a devicetree schema for AD7292 monitor and control system. Signed-off-by: Marcelo Schmitt --- Changelog V3 -> V4: - updated SPDX identifier to GPL-2.0-only - changed maxitems constraint on channel property .../bindings/iio/adc/adi,ad7292.yaml | 104 ++++++++++++++++++ MAINTAINERS | 7 ++ 2 files changed, 111 insertions(+) create mode 100644 Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml new file mode 100644 index 000000000000..b68be3aaf587 --- /dev/null +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml @@ -0,0 +1,104 @@ +# SPDX-License-Identifier: GPL-2.0-only +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/iio/adc/adi,ad7292.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Analog Devices AD7292 10-Bit Monitor and Control System + +maintainers: + - Marcelo Schmitt + +description: | + Analog Devices AD7292 10-Bit Monitor and Control System with ADC, DACs, + Temperature Sensor, and GPIOs + + Specifications about the part can be found at: + https://www.analog.com/media/en/technical-documentation/data-sheets/ad7292.pdf + +properties: + compatible: + enum: + - adi,ad7292 + + reg: + maxItems: 1 + + vref-supply: + description: | + The regulator supply for ADC and DAC reference voltage. + + spi-cpha: true + + '#address-cells': + const: 1 + + '#size-cells': + const: 0 + +required: + - compatible + - reg + - spi-cpha + +patternProperties: + "^channel@[0-7]$": + type: object + description: | + Represents the external channels which are connected to the ADC. + See Documentation/devicetree/bindings/iio/adc/adc.txt. + + properties: + reg: + description: | + The channel number. It can have up to 8 channels numbered from 0 to 7. + items: + maximum: 7 + + diff-channels: + description: see Documentation/devicetree/bindings/iio/adc/adc.txt + maxItems: 1 + + required: + - reg + +examples: + - | + spi { + #address-cells = <1>; + #size-cells = <0>; + + ad7292: adc@0 { + compatible = "adi,ad7292"; + reg = <0>; + spi-max-frequency = <25000000>; + vref-supply = <&adc_vref>; + spi-cpha; + + #address-cells = <1>; + #size-cells = <0>; + + channel@0 { + reg = <0>; + diff-channels = <0 1>; + }; + channel@2 { + reg = <2>; + }; + channel@3 { + reg = <3>; + }; + channel@4 { + reg = <4>; + }; + channel@5 { + reg = <5>; + }; + channel@6 { + reg = <6>; + }; + channel@7 { + reg = <7>; + }; + }; + }; diff --git a/MAINTAINERS b/MAINTAINERS index 32bf5f8116d0..5d00e871c4c6 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -813,6 +813,13 @@ S: Supported F: drivers/iio/adc/ad7124.c F: Documentation/devicetree/bindings/iio/adc/adi,ad7124.txt +ANALOG DEVICES INC AD7292 DRIVER +M: Marcelo Schmitt +L: linux-iio@vger.kernel.org +W: http://ez.analog.com/community/linux-device-drivers +S: Supported +F: Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml + ANALOG DEVICES INC AD7606 DRIVER M: Stefan Popa L: linux-iio@vger.kernel.org From patchwork Fri Nov 8 13:56:50 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marcelo Schmitt X-Patchwork-Id: 11234901 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 666F11709 for ; Fri, 8 Nov 2019 13:56:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3A7B721D7F for ; Fri, 8 Nov 2019 13:56:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="N1be/F3M" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726616AbfKHN45 (ORCPT ); Fri, 8 Nov 2019 08:56:57 -0500 Received: from mail-qt1-f193.google.com ([209.85.160.193]:38449 "EHLO mail-qt1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726307AbfKHN45 (ORCPT ); Fri, 8 Nov 2019 08:56:57 -0500 Received: by mail-qt1-f193.google.com with SMTP id p20so6562321qtq.5; Fri, 08 Nov 2019 05:56:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=fr+fOzNosfHP0Tp2y2igWIUUwB2Y8o78v//UEBNfK1s=; b=N1be/F3Mis3T8PsInSziJNPrdJBx8xEXMM0MErZmazCVYtu5+j7VkIIkdtcBy92SO1 6wm61EcWBxV3X3h2uRrvK1Gba8JHQRacLJNFBQfIy1KwyBu8dz2BjgsbMVykPmRrSzWd vzA7b/TNpSE4z50JA5mL7p809NYOiw1Y2zxSbbXMl0zqO28N1wSWmSGAuqXYcooTThT9 CnycNqq2u/W5M5YSm6s6feZdsM4cfYRsN6wRv8pGgmNc53fF4Ps4nt2TIU7ga7RsJFOt w2aDWw+m2Uyx0NbWWg9k9v5B7lO9VGc8LsTDG3m+p4JaA0Rxzq2++tXVhcE8JM3jAFVO Tw3Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=fr+fOzNosfHP0Tp2y2igWIUUwB2Y8o78v//UEBNfK1s=; b=iald6MsH5lqfuwpC2jG+lMsOW465yQttu4/bYyxBYTpYhqm6G+JOGs6lMARa0EinuY hnMb7FrzuMEH8haJ3RUIebWYnaZeJhlfHtKaA66Pncx9LuawJaaWqG+dZUSDAUVDHAKp ialczkmovRLIozEnN/UP1t8K4/86I1mZPYgvPUrap5btoBoOrvcaAfaBUue769WCStE1 OxGbMQNQ3tRFnhy2J3IBk/pJURnosDDqY+9uqgi6HigwZLp3rFn50aStQCL+R7lnvxLe m0IT2TYmRMbyw2x261ZYdvBZnjDNHbhnmSKb6gpDEjBIk9kOSxfj1ws3j41dhm41q/St sePw== X-Gm-Message-State: APjAAAWM8FspiMDqaHwC5gMO0mfAjc36QygsUlt3lUKw7fjYX4LPLEj7 lBbJ+77zmwG4yxSuTIka+MY= X-Google-Smtp-Source: APXvYqy3UFLdD1IGCaShpSzvMAIf1Zl6RtszGRMCL4YJigd/NJHuWMLjuUmEu9v2fmZVd8qfr4Dhbw== X-Received: by 2002:ac8:6641:: with SMTP id j1mr10903266qtp.48.1573221416224; Fri, 08 Nov 2019 05:56:56 -0800 (PST) Received: from smtp.gmail.com ([2804:d43:422:3955:b4df:7a81:96e1:236e]) by smtp.gmail.com with ESMTPSA id w20sm2512800qkj.87.2019.11.08.05.56.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 08 Nov 2019 05:56:55 -0800 (PST) Date: Fri, 8 Nov 2019 10:56:50 -0300 From: Marcelo Schmitt To: jic23@kernel.org, robh@kernel.org Cc: dragos.bogdan@analog.com, alexandru.ardelean@analog.com, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org, devicetree@vger.kernel.org, kernel-usp@googlegroups.com Subject: [PATCH v4 2/2] iio: adc: Add driver support for AD7292 Message-ID: References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180716 Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org The AD7292 is a 10-bit monitor and control system with ADC, DACs, temperature sensor, and GPIOs. Configure AD7292 devices in direct access mode, enabling single-ended ADC readings. Datasheet: Link: https://www.analog.com/media/en/technical-documentation/data-sheets/ad7292.pdf Signed-off-by: Marcelo Schmitt --- Changelog V3 -> V4: - added brackets to shield macro parameters MAINTAINERS | 1 + drivers/iio/adc/Kconfig | 10 ++ drivers/iio/adc/Makefile | 1 + drivers/iio/adc/ad7292.c | 350 +++++++++++++++++++++++++++++++++++++++ 4 files changed, 362 insertions(+) create mode 100644 drivers/iio/adc/ad7292.c diff --git a/MAINTAINERS b/MAINTAINERS index 5d00e871c4c6..5941cfc0d6f7 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -818,6 +818,7 @@ M: Marcelo Schmitt L: linux-iio@vger.kernel.org W: http://ez.analog.com/community/linux-device-drivers S: Supported +F: drivers/iio/adc/ad7292.c F: Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml ANALOG DEVICES INC AD7606 DRIVER diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 632b331429c6..02587c990cb5 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -59,6 +59,16 @@ config AD7291 To compile this driver as a module, choose M here: the module will be called ad7291. +config AD7292 + tristate "Analog Devices AD7292 ADC driver" + depends on SPI + help + Say yes here to build support for Analog Devices AD7292 + 8 Channel ADC with temperature sensor. + + To compile this driver as a module, choose M here: the + module will be called ad7292. + config AD7298 tristate "Analog Devices AD7298 ADC driver" depends on SPI diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index 4779ab3ff8fb..1818f2f66566 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -11,6 +11,7 @@ obj-$(CONFIG_AD7124) += ad7124.o obj-$(CONFIG_AD7173) += ad7173.o obj-$(CONFIG_AD7266) += ad7266.o obj-$(CONFIG_AD7291) += ad7291.o +obj-$(CONFIG_AD7292) += ad7292.o obj-$(CONFIG_AD7298) += ad7298.o obj-$(CONFIG_AD738X) += ad738x.o obj-$(CONFIG_AD7768) += ad7768-1.o diff --git a/drivers/iio/adc/ad7292.c b/drivers/iio/adc/ad7292.c new file mode 100644 index 000000000000..a6798f7dfdb8 --- /dev/null +++ b/drivers/iio/adc/ad7292.c @@ -0,0 +1,350 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Analog Devices AD7292 SPI ADC driver + * + * Copyright 2019 Analog Devices Inc. + */ + +#include +#include +#include +#include +#include + +#include + +#define ADI_VENDOR_ID 0x0018 + +/* AD7292 registers definition */ +#define AD7292_REG_VENDOR_ID 0x00 +#define AD7292_REG_CONF_BANK 0x05 +#define AD7292_REG_CONV_COMM 0x0E +#define AD7292_REG_ADC_CH(x) (0x10 + (x)) + +/* AD7292 configuration bank subregisters definition */ +#define AD7292_BANK_REG_VIN_RNG0 0x10 +#define AD7292_BANK_REG_VIN_RNG1 0x11 +#define AD7292_BANK_REG_SAMP_MODE 0x12 + +#define AD7292_RD_FLAG_MSK(x) (BIT(7) | ((x) & 0x3F)) + +/* AD7292_REG_ADC_CONVERSION */ +#define AD7292_ADC_DATA_MASK GENMASK(15, 6) +#define AD7292_ADC_DATA(x) FIELD_GET(AD7292_ADC_DATA_MASK, x) + +/* AD7292_CHANNEL_SAMPLING_MODE */ +#define AD7292_CH_SAMP_MODE(reg, ch) (((reg) >> 8) & BIT(ch)) + +/* AD7292_CHANNEL_VIN_RANGE */ +#define AD7292_CH_VIN_RANGE(reg, ch) ((reg) & BIT(ch)) + +#define AD7292_VOLTAGE_CHAN(_chan) \ +{ \ + .type = IIO_VOLTAGE, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_SCALE), \ + .indexed = 1, \ + .channel = _chan, \ +} + +static const struct iio_chan_spec ad7292_channels[] = { + AD7292_VOLTAGE_CHAN(0), + AD7292_VOLTAGE_CHAN(1), + AD7292_VOLTAGE_CHAN(2), + AD7292_VOLTAGE_CHAN(3), + AD7292_VOLTAGE_CHAN(4), + AD7292_VOLTAGE_CHAN(5), + AD7292_VOLTAGE_CHAN(6), + AD7292_VOLTAGE_CHAN(7) +}; + +static const struct iio_chan_spec ad7292_channels_diff[] = { + { + .type = IIO_VOLTAGE, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .indexed = 1, + .differential = 1, + .channel = 0, + .channel2 = 1, + }, + AD7292_VOLTAGE_CHAN(2), + AD7292_VOLTAGE_CHAN(3), + AD7292_VOLTAGE_CHAN(4), + AD7292_VOLTAGE_CHAN(5), + AD7292_VOLTAGE_CHAN(6), + AD7292_VOLTAGE_CHAN(7) +}; + +struct ad7292_state { + struct spi_device *spi; + struct regulator *reg; + unsigned short vref_mv; + + __be16 d16 ____cacheline_aligned; + u8 d8[2]; +}; + +static int ad7292_spi_reg_read(struct ad7292_state *st, unsigned int addr) +{ + int ret; + + st->d8[0] = AD7292_RD_FLAG_MSK(addr); + + ret = spi_write_then_read(st->spi, st->d8, 1, &st->d16, 2); + if (ret < 0) + return ret; + + return be16_to_cpu(st->d16); +} + +static int ad7292_spi_subreg_read(struct ad7292_state *st, unsigned int addr, + unsigned int sub_addr, unsigned int len) +{ + unsigned int shift = 16 - (8 * len); + int ret; + + st->d8[0] = AD7292_RD_FLAG_MSK(addr); + st->d8[1] = sub_addr; + + ret = spi_write_then_read(st->spi, st->d8, 2, &st->d16, len); + if (ret < 0) + return ret; + + return (be16_to_cpu(st->d16) >> shift); +} + +static int ad7292_single_conversion(struct ad7292_state *st, + unsigned int chan_addr) +{ + int ret; + + struct spi_transfer t[] = { + { + .tx_buf = &st->d8, + .len = 4, + .delay_usecs = 6, + }, { + .rx_buf = &st->d16, + .len = 2, + }, + }; + + st->d8[0] = chan_addr; + st->d8[1] = AD7292_RD_FLAG_MSK(AD7292_REG_CONV_COMM); + + ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t)); + + if (ret < 0) + return ret; + + return be16_to_cpu(st->d16); +} + +static int ad7292_vin_range_multiplier(struct ad7292_state *st, int channel) +{ + int samp_mode, range0, range1, factor = 1; + + /* + * Every AD7292 ADC channel may have its input range adjusted according + * to the settings at the ADC sampling mode and VIN range subregisters. + * For a given channel, the minimum input range is equal to Vref, and it + * may be increased by a multiplier factor of 2 or 4 according to the + * following rule: + * If channel is being sampled with respect to AGND: + * factor = 4 if VIN range0 and VIN range1 equal 0 + * factor = 2 if only one of VIN ranges equal 1 + * factor = 1 if both VIN range0 and VIN range1 equal 1 + * If channel is being sampled with respect to AVDD: + * factor = 4 if VIN range0 and VIN range1 equal 0 + * Behavior is undefined if any of VIN range doesn't equal 0 + */ + + samp_mode = ad7292_spi_subreg_read(st, AD7292_REG_CONF_BANK, + AD7292_BANK_REG_SAMP_MODE, 2); + + if (samp_mode < 0) + return samp_mode; + + range0 = ad7292_spi_subreg_read(st, AD7292_REG_CONF_BANK, + AD7292_BANK_REG_VIN_RNG0, 2); + + if (range0 < 0) + return range0; + + range1 = ad7292_spi_subreg_read(st, AD7292_REG_CONF_BANK, + AD7292_BANK_REG_VIN_RNG1, 2); + + if (range1 < 0) + return range1; + + if (AD7292_CH_SAMP_MODE(samp_mode, channel)) { + /* Sampling with respect to AGND */ + if (!AD7292_CH_VIN_RANGE(range0, channel)) + factor *= 2; + + if (!AD7292_CH_VIN_RANGE(range1, channel)) + factor *= 2; + + } else { + /* Sampling with respect to AVDD */ + if (AD7292_CH_VIN_RANGE(range0, channel) || + AD7292_CH_VIN_RANGE(range1, channel)) + return -EPERM; + + factor = 4; + } + + return factor; +} + +static int ad7292_read_raw(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + int *val, int *val2, long info) +{ + struct ad7292_state *st = iio_priv(indio_dev); + unsigned int ch_addr; + int ret; + + switch (info) { + case IIO_CHAN_INFO_RAW: + ch_addr = AD7292_REG_ADC_CH(chan->channel); + ret = ad7292_single_conversion(st, ch_addr); + if (ret < 0) + return ret; + + *val = AD7292_ADC_DATA(ret); + + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + /* + * To convert a raw value to standard units, the IIO defines + * this formula: Scaled value = (raw + offset) * scale. + * For the scale to be a correct multiplier for (raw + offset), + * it must be calculated as the input range divided by the + * number of possible distinct input values. Given the ADC data + * is 10 bit long, it may assume 2^10 distinct values. + * Hence, scale = range / 2^10. The IIO_VAL_FRACTIONAL_LOG2 + * return type indicates to the IIO API to divide *val by 2 to + * the power of *val2 when returning from read_raw. + */ + + ret = ad7292_vin_range_multiplier(st, chan->channel); + if (ret < 0) + return ret; + + *val = st->vref_mv * ret; + *val2 = 10; + return IIO_VAL_FRACTIONAL_LOG2; + default: + break; + } + return -EINVAL; +} + +static const struct iio_info ad7292_info = { + .read_raw = ad7292_read_raw, +}; + +static void ad7292_regulator_disable(void *data) +{ + struct ad7292_state *st = data; + + regulator_disable(st->reg); +} + +static int ad7292_probe(struct spi_device *spi) +{ + struct ad7292_state *st; + struct iio_dev *indio_dev; + struct device_node *child; + bool diff_channels = 0; + int ret; + + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); + if (!indio_dev) + return -ENOMEM; + + st = iio_priv(indio_dev); + st->spi = spi; + + ret = ad7292_spi_reg_read(st, AD7292_REG_VENDOR_ID); + if (ret != ADI_VENDOR_ID) { + dev_err(&spi->dev, "Wrong vendor id 0x%x\n", ret); + return -EINVAL; + } + + spi_set_drvdata(spi, indio_dev); + + st->reg = devm_regulator_get_optional(&spi->dev, "vref"); + if (!IS_ERR(st->reg)) { + ret = regulator_enable(st->reg); + if (ret) { + dev_err(&spi->dev, + "Failed to enable external vref supply\n"); + return ret; + } + + ret = devm_add_action_or_reset(&spi->dev, + ad7292_regulator_disable, st); + if (ret) { + regulator_disable(st->reg); + return ret; + } + + ret = regulator_get_voltage(st->reg); + if (ret < 0) + return ret; + + st->vref_mv = ret / 1000; + } else { + /* Use the internal voltage reference. */ + st->vref_mv = 1250; + } + + indio_dev->dev.parent = &spi->dev; + indio_dev->name = spi_get_device_id(spi)->name; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->info = &ad7292_info; + + for_each_available_child_of_node(spi->dev.of_node, child) { + diff_channels = of_property_read_bool(child, "diff-channels"); + if (diff_channels) + break; + } + + if (diff_channels) { + indio_dev->num_channels = ARRAY_SIZE(ad7292_channels_diff); + indio_dev->channels = ad7292_channels_diff; + } else { + indio_dev->num_channels = ARRAY_SIZE(ad7292_channels); + indio_dev->channels = ad7292_channels; + } + + return devm_iio_device_register(&spi->dev, indio_dev); +} + +static const struct spi_device_id ad7292_id_table[] = { + { "ad7292", 0 }, + {} +}; +MODULE_DEVICE_TABLE(spi, ad7292_id_table); + +static const struct of_device_id ad7292_of_match[] = { + { .compatible = "adi,ad7292" }, + { }, +}; +MODULE_DEVICE_TABLE(of, ad7292_of_match); + +static struct spi_driver ad7292_driver = { + .driver = { + .name = "ad7292", + .of_match_table = ad7292_of_match, + }, + .probe = ad7292_probe, + .id_table = ad7292_id_table, +}; +module_spi_driver(ad7292_driver); + +MODULE_AUTHOR("Marcelo Schmitt "); +MODULE_DESCRIPTION("Analog Devices AD7292 ADC driver"); +MODULE_LICENSE("GPL v2");