From patchwork Tue Feb 20 15:34:53 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Ceclan, Dumitru" X-Patchwork-Id: 13564177 Received: from mail-ed1-f46.google.com (mail-ed1-f46.google.com [209.85.208.46]) (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 2938E77625; Tue, 20 Feb 2024 15:36:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.46 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708443368; cv=none; b=HUGkIu8NLKXKggUyHN2IwPXcdvGB/4lIn0p54p0zYwW0PYFQfvgT4iq7wxh7RjMlinhOxZvCAFTRpPwBEN0VxRMrAgb/ZNQoxmXKDsW6roncZGoAErxnJ3ldH5HYrlIKQlJMo4XME97OEYk1oaWCwaS3kyg+AO0MZbcagBaYub4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708443368; c=relaxed/simple; bh=yngViWPOAMHAODTTAwgLH5RffJRA3vHYGb/gjQx44BA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=QN7GKtoX+dGvsHYMkcGA8hxRL7bacb9StkJDJoXCa5Mmj4KhQKu+fSEEuGMSzE5/XbqJTFvLcf1vtBhh4tteC2wUw38tAk3YToWQ5GrdiCMpylsApjX28D5vsBNvIVnWFc0/qoD1cqpg72kGCUlq7YfpcNduyRmNSsRrvbMzx6g= 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=e+DntWSc; arc=none smtp.client-ip=209.85.208.46 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="e+DntWSc" Received: by mail-ed1-f46.google.com with SMTP id 4fb4d7f45d1cf-564d9b0e96dso706754a12.2; Tue, 20 Feb 2024 07:36:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1708443364; x=1709048164; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=geyL8OfscOjPv2YlXwfaUvMZU6dkavwR22sE4+gZy1A=; b=e+DntWScsguJci0a0JpZECFHbaTgHAckoXtbSdNvSMvbmRL/SrH218OgmAdETxiofY K3+8lLN0XV4k8n0fNgSXjPS8S+muVjlPiEOgT03meAPZuvBb7JG2Apu30+w4ozZg2kSW u6rAisvA2HnczDzJF9KUbNV94IwiTocpcer94ZWZmyWd+HNGudSqw8npYubNlnzii5We ckCs2G1Ly5FFUq5mXOCFFfXAkKnB8tIVLtQg+HDrtN9oKNsSInm+DQ9sBj1k5/ir0ae8 5HsoLekMEdJIO0tCuGOc/lDvznwJyWxWNkovi25VNuqCDd+aQhpxrc/7Rmh1j8tGfcuH KQRg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1708443364; x=1709048164; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=geyL8OfscOjPv2YlXwfaUvMZU6dkavwR22sE4+gZy1A=; b=Epf/jzBqEi0qrBilTsD1fVWSMOA5TkQpJKkEqznh8F2F8NuD0IbnCo2rRfCPmfDKTa ZKpUFt8TtEuhC3Z8dWAipmHiUI+QR8NrvP4dl2vjT0EE1IW15vych1MnVmgxtr47qAhF 8mMmkb4cWD1/8m5p8abNc/eAX4TpNmACsI8Dvruke/6FOTlpS9XMzZZSWWYhoUmo8xVe l0qCpEes5y7PriCto2GFAvUmuZw8Ol2SqzC8mYcctriaV4tRBH7T08V+lTJTpmrGIo7p LHmJQOv+RP4uZF8WIB0Ph5guCcsouMdMAhOmWXo+TO7TqP2GRKfXXOP0Wx3uLnKQdVLV 94Pw== X-Forwarded-Encrypted: i=1; AJvYcCUBDsJPsvPVAKNU79NNaRL2n8C64YQTmUHXjoYpl1WLKkBxywxMvkRfzAwnXn3B5sjTloOecXNHth0Pe+dpPFtJqZma+6nSsuHS/0eWxgJIdm0kpcUyeGJa3Pu8zOkV2XfHDAj0RFuwdTC9QCjRt3Ob1d9BbzDbIh8eS+/hHbVfemFeJA== X-Gm-Message-State: AOJu0YzaiXbphNxr/8DUqJC5VV4bY8XJnRFS/MkpAWJjzBPbNmVLgQ9u k5MjuTuQMaY8VH7VhTctMtDOfV1xwaQg3yADrnb4uIQYuFSiuiorod7LEGqQUa+h3hIY X-Google-Smtp-Source: AGHT+IGLMDm3ARrwgLRHtJQorhTGCrr++X65+2urQqfqV1DRT2pDJexdtFgo/FBtACLc10UWEePyIA== X-Received: by 2002:a17:906:2a90:b0:a3e:1a96:a22c with SMTP id l16-20020a1709062a9000b00a3e1a96a22cmr6049808eje.38.1708443364117; Tue, 20 Feb 2024 07:36:04 -0800 (PST) Received: from HYB-hhAwRlzzMZb.ad.analog.com ([5.2.194.157]) by smtp.gmail.com with ESMTPSA id r22-20020a170906281600b00a3d777aa8fesm4039024ejc.69.2024.02.20.07.36.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 20 Feb 2024 07:36:03 -0800 (PST) From: Dumitru Ceclan To: Cc: Lars-Peter Clausen , Jonathan Cameron , Rob Herring , Krzysztof Kozlowski , Conor Dooley , linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Ceclan Dumitru , Dumitru Ceclan Subject: [PATCH v5 5/5] iio: amplifiers: hmc425a: add support for LTC6373 Instrumentation Amplifier Date: Tue, 20 Feb 2024 17:34:53 +0200 Message-ID: <20240220153553.2432-6-mitrutzceclan@gmail.com> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20240220153553.2432-1-mitrutzceclan@gmail.com> References: <20240220153553.2432-1-mitrutzceclan@gmail.com> Precedence: bulk X-Mailing-List: linux-iio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 This adds support for LTC6373 36 V Fully-Differential Programmable-Gain Instrumentation Amplifier with 25 pA Input Bias Current. The user can program the gain to one of seven available settings through a 3-bit parallel interface (A2 to A0). Signed-off-by: Dumitru Ceclan Reviewed-by: Nuno Sa --- drivers/iio/amplifiers/hmc425a.c | 124 ++++++++++++++++++++++++++++++- 1 file changed, 120 insertions(+), 4 deletions(-) diff --git a/drivers/iio/amplifiers/hmc425a.c b/drivers/iio/amplifiers/hmc425a.c index 77872e2dfdfe..50c86c2d28d7 100644 --- a/drivers/iio/amplifiers/hmc425a.c +++ b/drivers/iio/amplifiers/hmc425a.c @@ -2,9 +2,10 @@ /* * HMC425A and similar Gain Amplifiers * - * Copyright 2020 Analog Devices Inc. + * Copyright 2020, 2024 Analog Devices Inc. */ +#include #include #include #include @@ -12,6 +13,7 @@ #include #include #include +#include #include #include #include @@ -20,10 +22,24 @@ #include #include +/* + * The LTC6373 amplifier supports configuring gain using GPIO's with the following + * values (OUTPUT_V / INPUT_V): 0(shutdown), 0.25, 0.5, 1, 2, 4, 8, 16 + * + * Except for the shutdown value, all can be converted to dB using 20 * log10(x) + * From here, it is observed that all values are multiples of the '2' gain setting, + * with the correspondent of 6.020dB. + */ +#define LTC6373_CONVERSION_CONSTANT 6020 +#define LTC6373_MIN_GAIN_CODE 0x6 +#define LTC6373_CONVERSION_MASK GENMASK(2, 0) +#define LTC6373_SHUTDOWN GENMASK(2, 0) + enum hmc425a_type { ID_HMC425A, ID_HMC540S, - ID_ADRF5740 + ID_ADRF5740, + ID_LTC6373, }; struct hmc425a_chip_info { @@ -34,6 +50,8 @@ struct hmc425a_chip_info { int gain_min; int gain_max; int default_gain; + int powerdown_val; + bool has_powerdown; int (*gain_dB_to_code)(int gain, int *code); int (*code_to_gain_dB)(int code, int *val, int *val2); @@ -44,6 +62,7 @@ struct hmc425a_state { const struct hmc425a_chip_info *chip_info; struct gpio_descs *gpios; u32 gain; + bool powerdown; }; static int gain_dB_to_code(struct hmc425a_state *st, int val, int val2, int *code) @@ -58,6 +77,8 @@ static int gain_dB_to_code(struct hmc425a_state *st, int val, int val2, int *cod if (gain > inf->gain_max || gain < inf->gain_min) return -EINVAL; + if (st->powerdown) + return -EPERM; return st->chip_info->gain_dB_to_code(gain, code); } @@ -83,8 +104,17 @@ static int adrf5740_gain_dB_to_code(int gain, int *code) return 0; } +static int ltc6373_gain_dB_to_code(int gain, int *code) +{ + *code = ~(DIV_ROUND_CLOSEST(gain, LTC6373_CONVERSION_CONSTANT) + 3) + & LTC6373_CONVERSION_MASK; + return 0; +} + static int code_to_gain_dB(struct hmc425a_state *st, int *val, int *val2) { + if (st->powerdown) + return -EPERM; return st->chip_info->code_to_gain_dB(st->gain, val, val2); } @@ -114,6 +144,16 @@ static int adrf5740_code_to_gain_dB(int code, int *val, int *val2) return 0; } +static int ltc6373_code_to_gain_dB(int code, int *val, int *val2) +{ + int gain = ((~code & LTC6373_CONVERSION_MASK) - 3) * + LTC6373_CONVERSION_CONSTANT; + + *val = gain / 1000; + *val2 = (gain % 1000) * 1000; + return 0; +} + static int hmc425a_write(struct iio_dev *indio_dev, u32 value) { struct hmc425a_state *st = iio_priv(indio_dev); @@ -191,6 +231,48 @@ static const struct iio_info hmc425a_info = { .write_raw_get_fmt = &hmc425a_write_raw_get_fmt, }; +static ssize_t ltc6373_read_powerdown(struct iio_dev *indio_dev, + uintptr_t private, + const struct iio_chan_spec *chan, + char *buf) +{ + struct hmc425a_state *st = iio_priv(indio_dev); + + return sysfs_emit(buf, "%d\n", st->powerdown); +} + +static ssize_t ltc6373_write_powerdown(struct iio_dev *indio_dev, + uintptr_t private, + const struct iio_chan_spec *chan, + const char *buf, + size_t len) +{ + struct hmc425a_state *st = iio_priv(indio_dev); + bool powerdown; + int code, ret; + + ret = kstrtobool(buf, &powerdown); + if (ret) + return ret; + + mutex_lock(&st->lock); + st->powerdown = powerdown; + code = (powerdown) ? LTC6373_SHUTDOWN : st->gain; + hmc425a_write(indio_dev, code); + mutex_unlock(&st->lock); + return len; +} + +static const struct iio_chan_spec_ext_info ltc6373_ext_info[] = { + { + .name = "powerdown", + .read = ltc6373_read_powerdown, + .write = ltc6373_write_powerdown, + .shared = IIO_SEPARATE, + }, + {} +}; + #define HMC425A_CHAN(_channel) \ { \ .type = IIO_VOLTAGE, \ @@ -200,10 +282,24 @@ static const struct iio_info hmc425a_info = { .info_mask_separate = BIT(IIO_CHAN_INFO_HARDWAREGAIN), \ } +#define LTC6373_CHAN(_channel) \ +{ \ + .type = IIO_VOLTAGE, \ + .output = 1, \ + .indexed = 1, \ + .channel = _channel, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_HARDWAREGAIN), \ + .ext_info = ltc6373_ext_info, \ +} + static const struct iio_chan_spec hmc425a_channels[] = { HMC425A_CHAN(0), }; +static const struct iio_chan_spec ltc6373_channels[] = { + LTC6373_CHAN(0), +}; + static struct hmc425a_chip_info hmc425a_chip_info_tbl[] = { [ID_HMC425A] = { .name = "hmc425a", @@ -238,6 +334,19 @@ static struct hmc425a_chip_info hmc425a_chip_info_tbl[] = { .gain_dB_to_code = adrf5740_gain_dB_to_code, .code_to_gain_dB = adrf5740_code_to_gain_dB, }, + [ID_LTC6373] = { + .name = "ltc6373", + .channels = ltc6373_channels, + .num_channels = ARRAY_SIZE(ltc6373_channels), + .num_gpios = 3, + .gain_min = -12041, /* gain setting x0.25*/ + .gain_max = 24082, /* gain setting x16 */ + .default_gain = LTC6373_MIN_GAIN_CODE, + .powerdown_val = LTC6373_SHUTDOWN, + .has_powerdown = true, + .gain_dB_to_code = ltc6373_gain_dB_to_code, + .code_to_gain_dB = ltc6373_code_to_gain_dB, + }, }; static int hmc425a_probe(struct platform_device *pdev) @@ -278,8 +387,13 @@ static int hmc425a_probe(struct platform_device *pdev) indio_dev->info = &hmc425a_info; indio_dev->modes = INDIO_DIRECT_MODE; - /* Set default gain */ - hmc425a_write(indio_dev, st->gain); + if (st->chip_info->has_powerdown) { + st->powerdown = true; + hmc425a_write(indio_dev, st->chip_info->powerdown_val); + } else { + /* Set default gain */ + hmc425a_write(indio_dev, st->gain); + } return devm_iio_device_register(&pdev->dev, indio_dev); } @@ -292,6 +406,8 @@ static const struct of_device_id hmc425a_of_match[] = { .data = &hmc425a_chip_info_tbl[ID_HMC540S]}, { .compatible = "adi,adrf5740", .data = &hmc425a_chip_info_tbl[ID_ADRF5740]}, + { .compatible = "adi,ltc6373", + .data = &hmc425a_chip_info_tbl[ID_LTC6373]}, {} }; MODULE_DEVICE_TABLE(of, hmc425a_of_match);