From nobody Thu Apr 9 11:16:51 2026 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 33101376BEC; Mon, 9 Mar 2026 12:13:12 +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=1773058393; cv=none; b=kylyrYULDtIterchKNsqHKv47t/NQ2y3n1p0rzZEt0Ev0dkIAa9NdCKNpv8a8cxdps7wmAA8lia4Xifi7/pNRa8zV0jHyKFYNjceslWkIlZJIGA7U+CEax3nPhQgT45+NARq34T2mtx9Cip7mKEmwmv/XD3p2ndSIuxyQBiWusk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773058393; c=relaxed/simple; bh=lmww/AnRT4CLgt5Rdb6gYI6yta72w2KvFetRCs2bDTE=; h=From:Date:Subject:MIME-Version:Content-Type:Message-ID:To:CC; b=SjuCHgvVNixm9YKojyp+TrQwYTl/K5JXj/Kpqup+5jPXFXXV6ymSke64RHXAz7vUHbHZdlLNLqjAyAruMBl/AFap33qcaX5enDfOtBXBudDZN/IxzFGazgXMJhUlm636XLM0iVBUauaXoE5bnP4MaQiyCQVO7sK1I5yNjGoXMgg= 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=KjO/liJ5; 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="KjO/liJ5" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1773058392; x=1804594392; h=from:date:subject:mime-version:content-transfer-encoding: message-id:to:cc; bh=lmww/AnRT4CLgt5Rdb6gYI6yta72w2KvFetRCs2bDTE=; b=KjO/liJ5bdVr4QrlGzrE6tFmB0SZQG0mbMv0dXmuNWBbigBmWh7W+QcT nDJ/bfL7bRDnJiMZPL42q7XYrRVynJg+75d8kGL9r7TLo5qEkzcCcxU8N zoV8D7mdrm3wyI/KCW8Dxs0rABUZeTlWKDoLArgTXF7kX2xRkBKIeSFR9 zYOHmf+g6h14TsmdJU3qIq5tNZ51t6pTtvo84zilX84lPlNxn3wn9IqUb yswYNsxKLcWrZV5NQHb0h2DmOh8pR9l4Zrz1CsR2j0BLvumjqTYMd5MyI s5lVAM3Ctj+Y5xKiDxoXS0GN482L3GAkykE4VVTu1ogzjFPD7dxq1fFjD A==; X-CSE-ConnectionGUID: IN4R9I4iQ/2y5EFaLyde3Q== X-CSE-MsgGUID: 7gYo2ZEOTLq1STbCspBBaw== X-IronPort-AV: E=Sophos;i="6.23,109,1770620400"; d="scan'208";a="285784267" X-Amp-Result: SKIPPED(no attachment in message) Received: from unknown (HELO email.microchip.com) ([170.129.1.10]) by esa5.microchip.iphmx.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Mar 2026 05:13:11 -0700 Received: from chn-vm-ex01.mchp-main.com (10.10.87.71) by chn-vm-ex1.mchp-main.com (10.10.87.30) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.2.2562.35; Mon, 9 Mar 2026 05:12:31 -0700 Received: from [127.0.1.1] (10.10.85.11) by chn-vm-ex01.mchp-main.com (10.10.85.143) with Microsoft SMTP Server id 15.1.2507.58 via Frontend Transport; Mon, 9 Mar 2026 05:12:29 -0700 From: Ariana Lazar Date: Mon, 9 Mar 2026 14:12:23 +0200 Subject: [PATCH v2] iio: dac: mcp47feb02: Fix Vref validation [1-999] case Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-ID: <20260309-mcp47feb02-fix1-v2-1-6a5ef30e4b27@microchip.com> X-B4-Tracking: v=1; b=H4sIACa5rmkC/2WNQQ7CIBREr9L8tRigSFNXvYfpQujH/gWFgCGah ruLTVy5fJOZNztkTIQZrt0OCQtlClsDeerArvftgYyWxiC51Lzninkb1eDQcMkcvQSTfFncaAd htIa2iglbfhhvc+OV8jOk93FQxDf9uS5/riKYYFoZLfrWQD5OnmwKdqV4tsHDXGv9ACvqshmyA AAA X-Change-ID: 20260304-mcp47feb02-fix1-20ddf9c71b66 To: Jonathan Cameron , David Lechner , =?utf-8?q?Nuno_S=C3=A1?= , "Andy Shevchenko" CC: Jonathan Cameron , , , Ariana Lazar X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=ed25519-sha256; t=1773058348; l=6037; i=ariana.lazar@microchip.com; s=20250825; h=from:subject:message-id; bh=lmww/AnRT4CLgt5Rdb6gYI6yta72w2KvFetRCs2bDTE=; b=IHC/B/OFNNig9Vt7jwijJ7Iv/lC5jiEQ0Sf8+vXAkBgoKRMei+Q+Z3FkovxmR4GgkuTPOLn2d 6ctmRfl5pX0Aodz2+v7cyGS+uhWzHj0TSq8ljMf2TzQSefkFx4xqAzy X-Developer-Key: i=ariana.lazar@microchip.com; a=ed25519; pk=jmvf1fSxcnzZmXfITM3L94IwutM+wqA1POQHiYyD6Dk= Store reference voltages in uV instead of mV to avoid invalid error code in dev_err_probe() call. Vref variables store the actual value returned by devm_regulator_get_enable_read_voltage() function instead of the results of dividing it by MILLI. The corner case [1-999] divided by MILLI of the voltage reference variable value would become 0 is covered too. Fixes: bf394cc80369 ("iio: dac: adding support for Microchip MCP47FEB02") Link: https://lore.kernel.org/all/aYXvP5FLA5BvkoVX@stanley.mountain/ Signed-off-by: Ariana Lazar --- Changes in v2: - add () to functions mentioned in the commit message - split vref_uV, vref1_uV assigments - Link to v1: https://lore.kernel.org/r/20260305-mcp47feb02-fix1-v1-1-64b61= 3260e09@microchip.com --- drivers/iio/dac/mcp47feb02.c | 49 ++++++++++++++++++++--------------------= ---- 1 file changed, 22 insertions(+), 27 deletions(-) diff --git a/drivers/iio/dac/mcp47feb02.c b/drivers/iio/dac/mcp47feb02.c index b218f0c3a0bd79f43dc9f2da1027f49a04e1975b..5615b4f50e6527023da2f492f12= 268f64e59fab9 100644 --- a/drivers/iio/dac/mcp47feb02.c +++ b/drivers/iio/dac/mcp47feb02.c @@ -65,7 +65,7 @@ #define MCP47FEB02_MAX_SCALES_CH 3 #define MCP47FEB02_DAC_WIPER_UNLOCKED 0 #define MCP47FEB02_NORMAL_OPERATION 0 -#define MCP47FEB02_INTERNAL_BAND_GAP_mV 2440 +#define MCP47FEB02_INTERNAL_BAND_GAP_uV 2440000 #define NV_DAC_ADDR_OFFSET 0x10 =20 enum mcp47feb02_vref_mode { @@ -697,44 +697,40 @@ static const struct iio_chan_spec mcp47febxx_ch_templ= ate =3D { }; =20 static void mcp47feb02_init_scale(struct mcp47feb02_data *data, enum mcp47= feb02_scale scale, - int vref_mV, int scale_avail[]) + int vref_uV, int scale_avail[]) { u32 value_micro, value_int; u64 tmp; =20 - /* vref_mV should not be negative */ - tmp =3D (u64)vref_mV * MICRO >> data->chip_features->resolution; + /* vref_uV should not be negative */ + tmp =3D (u64)vref_uV * MILLI >> data->chip_features->resolution; value_int =3D div_u64_rem(tmp, MICRO, &value_micro); scale_avail[scale * 2] =3D value_int; scale_avail[scale * 2 + 1] =3D value_micro; } =20 -static int mcp47feb02_init_scales_avail(struct mcp47feb02_data *data, int = vdd_mV, - int vref_mV, int vref1_mV) +static int mcp47feb02_init_scales_avail(struct mcp47feb02_data *data, int = vdd_uV, + int vref_uV, int vref1_uV) { - struct device *dev =3D regmap_get_device(data->regmap); int tmp_vref; =20 - mcp47feb02_init_scale(data, MCP47FEB02_SCALE_VDD, vdd_mV, data->scale); + mcp47feb02_init_scale(data, MCP47FEB02_SCALE_VDD, vdd_uV, data->scale); =20 if (data->use_vref) - tmp_vref =3D vref_mV; + tmp_vref =3D vref_uV; else - tmp_vref =3D MCP47FEB02_INTERNAL_BAND_GAP_mV; + tmp_vref =3D MCP47FEB02_INTERNAL_BAND_GAP_uV; =20 mcp47feb02_init_scale(data, MCP47FEB02_SCALE_GAIN_X1, tmp_vref, data->sca= le); mcp47feb02_init_scale(data, MCP47FEB02_SCALE_GAIN_X2, tmp_vref * 2, data-= >scale); =20 if (data->phys_channels >=3D 4) { - mcp47feb02_init_scale(data, MCP47FEB02_SCALE_VDD, vdd_mV, data->scale_1); - - if (data->use_vref1 && vref1_mV <=3D 0) - return dev_err_probe(dev, vref1_mV, "Invalid voltage for Vref1\n"); + mcp47feb02_init_scale(data, MCP47FEB02_SCALE_VDD, vdd_uV, data->scale_1); =20 if (data->use_vref1) - tmp_vref =3D vref1_mV; + tmp_vref =3D vref1_uV; else - tmp_vref =3D MCP47FEB02_INTERNAL_BAND_GAP_mV; + tmp_vref =3D MCP47FEB02_INTERNAL_BAND_GAP_uV; =20 mcp47feb02_init_scale(data, MCP47FEB02_SCALE_GAIN_X1, tmp_vref, data->scale_1); @@ -1080,8 +1076,8 @@ static int mcp47feb02_init_ctrl_regs(struct mcp47feb0= 2_data *data) return 0; } =20 -static int mcp47feb02_init_ch_scales(struct mcp47feb02_data *data, int vdd= _mV, - int vref_mV, int vref1_mV) +static int mcp47feb02_init_ch_scales(struct mcp47feb02_data *data, int vdd= _uV, + int vref_uV, int vref1_uV) { unsigned int i; =20 @@ -1089,7 +1085,7 @@ static int mcp47feb02_init_ch_scales(struct mcp47feb0= 2_data *data, int vdd_mV, struct device *dev =3D regmap_get_device(data->regmap); int ret; =20 - ret =3D mcp47feb02_init_scales_avail(data, vdd_mV, vref_mV, vref1_mV); + ret =3D mcp47feb02_init_scales_avail(data, vdd_uV, vref_uV, vref1_uV); if (ret) return dev_err_probe(dev, ret, "failed to init scales for ch %u\n", i); } @@ -1103,10 +1099,7 @@ static int mcp47feb02_probe(struct i2c_client *clien= t) struct device *dev =3D &client->dev; struct mcp47feb02_data *data; struct iio_dev *indio_dev; - int vref1_mV =3D 0; - int vref_mV =3D 0; - int vdd_mV; - int ret; + int vref1_uV, vref_uV, vdd_uV, ret; =20 indio_dev =3D devm_iio_device_alloc(dev, sizeof(*data)); if (!indio_dev) @@ -1143,11 +1136,12 @@ static int mcp47feb02_probe(struct i2c_client *clie= nt) if (ret < 0) return ret; =20 - vdd_mV =3D ret / MILLI; + vdd_uV =3D ret; =20 + vref_uV =3D 0; ret =3D devm_regulator_get_enable_read_voltage(dev, "vref"); if (ret > 0) { - vref_mV =3D ret / MILLI; + vref_uV =3D ret; data->use_vref =3D true; } else { dev_dbg(dev, "using internal band gap as voltage reference.\n"); @@ -1155,9 +1149,10 @@ static int mcp47feb02_probe(struct i2c_client *clien= t) } =20 if (chip_features->have_ext_vref1) { + vref1_uV =3D 0; ret =3D devm_regulator_get_enable_read_voltage(dev, "vref1"); if (ret > 0) { - vref1_mV =3D ret / MILLI; + vref1_uV =3D ret; data->use_vref1 =3D true; } else { dev_dbg(dev, "using internal band gap as voltage reference 1.\n"); @@ -1169,7 +1164,7 @@ static int mcp47feb02_probe(struct i2c_client *client) if (ret) return dev_err_probe(dev, ret, "Error initialising vref register\n"); =20 - ret =3D mcp47feb02_init_ch_scales(data, vdd_mV, vref_mV, vref1_mV); + ret =3D mcp47feb02_init_ch_scales(data, vdd_uV, vref_uV, vref1_uV); if (ret) return ret; =20 --- base-commit: bfd61205aca379121b1913885d4d06c51857119b change-id: 20260304-mcp47feb02-fix1-20ddf9c71b66 Best regards, --=20 Ariana Lazar