From patchwork Wed Oct 2 12:54:45 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: victor.duicu@microchip.com X-Patchwork-Id: 13819777 Received: from esa.microchip.iphmx.com (esa.microchip.iphmx.com [68.232.153.233]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0B5D01D0142; Wed, 2 Oct 2024 12:55:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=68.232.153.233 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727873756; cv=none; b=kpw1ix0C6Je5r/zPGGJFr/Z5gs2XIbCPKnFKx6uAKpVFVtTe/CRek7ObzSXJ6I7i0kVdl41zZ5+SyxJ6GWWzKlJuDDNm6d+fpj7eOMBJZ7p3yIIqVtySwGKA9VD3gobyJefO1zOdEbH23KVePlo85u+xd4z3+xdwud5amZn+QK0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727873756; c=relaxed/simple; bh=BcDRNCBRnAa17mYLsHFdZ52XN2PN8xlbFoQo+wI3gcE=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=qHbjy2Umqdio+kArJ1/X+kq7Bb1Hjf1C6GPORIOHzVvZgedSo9noiP+zOaGOySChqvAgS1jZEifjV7xiRfmw+3EN4FQ2jd9Ulqfza/8oOiSj8Y1PKUnQ0fBlwQJESboZo1BVwdsZez3tkVRgKCLz/d7vaRuDjmsVlTxaCYlqEI0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=microchip.com; spf=pass smtp.mailfrom=microchip.com; dkim=pass (2048-bit key) header.d=microchip.com header.i=@microchip.com header.b=wHCgL4cu; arc=none smtp.client-ip=68.232.153.233 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=microchip.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=microchip.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=microchip.com header.i=@microchip.com header.b="wHCgL4cu" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1727873754; x=1759409754; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=BcDRNCBRnAa17mYLsHFdZ52XN2PN8xlbFoQo+wI3gcE=; b=wHCgL4cu7yxL4a7Ww1CJNdqjOtUi0js0H7hF+l4Iy6Va2Q52JxAuDpEc SaDFmZ6O8LrJLnRAvLCnTWglLxDkUyK40gYS1X0+nWWfhL7VgS777eH7B f7nabLnd723wcPQTmTMDPJmMTwsQXrYxYQlrOaR2mDsADa2PW9oG7MmgV vvEuM8gdOuM/2jB89GegrMxR6LP9wJRWWSgCBDiYFSNW67lUECRa3Ra7z PqskExjxkwpC+5qHWNs87b3V16M3pM9a779yuGyDejK9QVPtoQ5EF/guO uJ6hBjHOJv86tUfbcEvCO/mJBIfs8WGbZuupxlxFBY+K4T/e/tFGvgQzl A==; X-CSE-ConnectionGUID: Va+YVzq4SVeiJMC18iElnA== X-CSE-MsgGUID: 0WF7gG8/QQCFKeai5VLxaQ== X-IronPort-AV: E=Sophos;i="6.11,171,1725346800"; d="scan'208";a="35789130" X-Amp-Result: SKIPPED(no attachment in message) Received: from unknown (HELO email.microchip.com) ([170.129.1.10]) by esa1.microchip.iphmx.com with ESMTP/TLS/ECDHE-RSA-AES128-GCM-SHA256; 02 Oct 2024 05:55:48 -0700 Received: from chn-vm-ex01.mchp-main.com (10.10.85.143) by chn-vm-ex01.mchp-main.com (10.10.85.143) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.35; Wed, 2 Oct 2024 05:55:07 -0700 Received: from vduicu-Virtual-Machine.mshome.net (10.10.85.11) by chn-vm-ex01.mchp-main.com (10.10.85.143) with Microsoft SMTP Server id 15.1.2507.35 via Frontend Transport; Wed, 2 Oct 2024 05:55:05 -0700 From: To: , , CC: , , , Subject: [PATCH v2] iio: adc: pac1921: add ACPI support to pac1921 Date: Wed, 2 Oct 2024 15:54:45 +0300 Message-ID: <20241002125445.7570-1-victor.duicu@microchip.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-iio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Victor Duicu This patch implements ACPI support to Microchip pac1921. The driver can read shunt resistor value and device label from ACPI table. Differences related to previous versions: v2: - remove name variable from priv. Driver reads label attribute with sysfs. - define pac1921_shunt_is_valid function. - move default assignments in pac1921_probe to original position. - roll back coding style changes. - add documentation for DSM(the linked document was used as reference). - remove acpi_match_device in pac1921_match_acpi_device. - remove unnecessary null assignment and comment. - change name of function pac1921_match_of_device to pac1921_parse_of_fw. v1: - initial version for review. Signed-off-by: Victor Duicu --- drivers/iio/adc/pac1921.c | 112 ++++++++++++++++++++++++++++++++++---- 1 file changed, 101 insertions(+), 11 deletions(-) base-commit: fec496684388685647652ab4213454fbabdab099 diff --git a/drivers/iio/adc/pac1921.c b/drivers/iio/adc/pac1921.c index 4c2a1c07bc39..95ade1c4d5e8 100644 --- a/drivers/iio/adc/pac1921.c +++ b/drivers/iio/adc/pac1921.c @@ -67,6 +67,10 @@ enum pac1921_mxsl { #define PAC1921_DEFAULT_DI_GAIN 0 /* 2^(value): 1x gain (HW default) */ #define PAC1921_DEFAULT_NUM_SAMPLES 0 /* 2^(value): 1 sample (HW default) */ +#define PAC1921_ACPI_GET_UOHMS_VALS 0 +#define PAC1921_ACPI_GET_NAME 1 +#define PAC1921_DSM_UUID "f7bb9932-86ee-4516-a236-7a7a742e55cb" + /* * Pre-computed scale factors for BUS voltage * format: IIO_VAL_INT_PLUS_NANO @@ -204,6 +208,14 @@ struct pac1921_priv { } scan; }; +static bool pac1921_shunt_is_valid(u32 shunt_val) +{ + if (shunt_val == 0 || shunt_val > INT_MAX) + return false; + else + return true; +} + /* * Check if first integration after configuration update has completed. * @@ -794,7 +806,7 @@ static ssize_t pac1921_write_shunt_resistor(struct iio_dev *indio_dev, return ret; rshunt_uohm = (u32)val * MICRO + (u32)val_fract; - if (rshunt_uohm == 0 || rshunt_uohm > INT_MAX) + if (!pac1921_shunt_is_valid((u32)rshunt_uohm)) return -EINVAL; guard(mutex)(&priv->lock); @@ -1151,6 +1163,81 @@ static void pac1921_regulator_disable(void *data) regulator_disable(regulator); } +/* + * documentation related to the ACPI device definition + * https://ww1.microchip.com/downloads/aemDocuments/documents/OTH/ApplicationNotes/ApplicationNotes/PAC1934-Integration-Notes-for-Microsoft-Windows-10-and-Windows-11-Driver-Support-DS00002534.pdf + */ +static int pac1921_match_acpi_device(struct i2c_client *client, struct pac1921_priv *priv, + struct iio_dev *indio_dev) +{ + acpi_handle handle; + union acpi_object *rez; + guid_t guid; + char *label; + + guid_parse(PAC1921_DSM_UUID, &guid); + handle = ACPI_HANDLE(&client->dev); + + rez = acpi_evaluate_dsm(handle, &guid, 1, PAC1921_ACPI_GET_UOHMS_VALS, NULL); + if (!rez) + return dev_err_probe(&client->dev, -EINVAL, + "Could not read shunt from ACPI table\n"); + + priv->rshunt_uohm = rez->package.elements[0].integer.value; + ACPI_FREE(rez); + + if (!pac1921_shunt_is_valid(priv->rshunt_uohm)) + return dev_err_probe(&client->dev, -EINVAL, "Invalid shunt resistor: %u\n", + priv->rshunt_uohm); + + pac1921_calc_current_scales(priv); + + rez = acpi_evaluate_dsm(handle, &guid, 1, PAC1921_ACPI_GET_NAME, NULL); + if (!rez) + return dev_err_probe(&client->dev, -EINVAL, + "Could not read name from ACPI table\n"); + + label = devm_kmemdup(&client->dev, rez->package.elements->string.pointer, + (size_t)rez->package.elements->string.length + 1, + GFP_KERNEL); + label[rez->package.elements->string.length] = '\0'; + indio_dev->label = label; + ACPI_FREE(rez); + + return 0; +} + +static int pac1921_parse_of_fw(struct i2c_client *client, struct pac1921_priv *priv, + struct iio_dev *indio_dev) +{ + int ret; + struct device *dev = &client->dev; + + ret = device_property_read_u32(dev, "shunt-resistor-micro-ohms", + &priv->rshunt_uohm); + if (ret) + return dev_err_probe(dev, ret, + "Cannot read shunt resistor property\n"); + + if (!pac1921_shunt_is_valid(priv->rshunt_uohm)) + return dev_err_probe(dev, -EINVAL, "Invalid shunt resistor: %u\n", + priv->rshunt_uohm); + + pac1921_calc_current_scales(priv); + + if (device_property_present(dev, "label")) { + ret = device_property_read_string(dev, "label", + (const char **)&indio_dev->label); + if (ret) + return dev_err_probe(&client->dev, ret, + "Invalid rail-name value\n"); + } else { + indio_dev->label = "pac1921"; + } + + return 0; +} + static int pac1921_probe(struct i2c_client *client) { struct device *dev = &client->dev; @@ -1177,17 +1264,14 @@ static int pac1921_probe(struct i2c_client *client) priv->di_gain = PAC1921_DEFAULT_DI_GAIN; priv->n_samples = PAC1921_DEFAULT_NUM_SAMPLES; - ret = device_property_read_u32(dev, "shunt-resistor-micro-ohms", - &priv->rshunt_uohm); - if (ret) - return dev_err_probe(dev, ret, - "Cannot read shunt resistor property\n"); - if (priv->rshunt_uohm == 0 || priv->rshunt_uohm > INT_MAX) - return dev_err_probe(dev, -EINVAL, - "Invalid shunt resistor: %u\n", - priv->rshunt_uohm); + if (ACPI_HANDLE(&client->dev)) + ret = pac1921_match_acpi_device(client, priv, indio_dev); + else + ret = pac1921_parse_of_fw(client, priv, indio_dev); - pac1921_calc_current_scales(priv); + if (ret < 0) + return dev_err_probe(&client->dev, ret, + "parameter parsing error\n"); priv->vdd = devm_regulator_get(dev, "vdd"); if (IS_ERR(priv->vdd)) @@ -1244,11 +1328,17 @@ static const struct of_device_id pac1921_of_match[] = { }; MODULE_DEVICE_TABLE(of, pac1921_of_match); +static const struct acpi_device_id pac1921_acpi_match[] = { + { "MCHP1921" }, + { } +}; +MODULE_DEVICE_TABLE(acpi, pac1921_acpi_match); static struct i2c_driver pac1921_driver = { .driver = { .name = "pac1921", .pm = pm_sleep_ptr(&pac1921_pm_ops), .of_match_table = pac1921_of_match, + .acpi_match_table = pac1921_acpi_match }, .probe = pac1921_probe, .id_table = pac1921_id,