From patchwork Fri Sep 2 13:13:51 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oleksij Rempel X-Patchwork-Id: 12964266 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1B7C6ECAAD5 for ; Fri, 2 Sep 2022 14:15:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238695AbiIBOPw (ORCPT ); Fri, 2 Sep 2022 10:15:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51730 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238944AbiIBOPU (ORCPT ); Fri, 2 Sep 2022 10:15:20 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D3C6814D465 for ; Fri, 2 Sep 2022 06:42:46 -0700 (PDT) Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1oU6Ue-0007Va-Hm; Fri, 02 Sep 2022 15:13:56 +0200 Received: from [2a0a:edc0:0:1101:1d::ac] (helo=dude04.red.stw.pengutronix.de) by drehscheibe.grey.stw.pengutronix.de with esmtp (Exim 4.94.2) (envelope-from ) id 1oU6Ub-003VMs-EQ; Fri, 02 Sep 2022 15:13:55 +0200 Received: from ore by dude04.red.stw.pengutronix.de with local (Exim 4.94.2) (envelope-from ) id 1oU6Uc-006elN-E7; Fri, 02 Sep 2022 15:13:54 +0200 From: Oleksij Rempel To: Jonathan Cameron , Lars-Peter Clausen , Rob Herring , Krzysztof Kozlowski Cc: Oleksij Rempel , kernel@pengutronix.de, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org, devicetree@vger.kernel.org, Andy Shevchenko Subject: [PATCH v4 2/3] iio: adc: tsc2046: add vref support Date: Fri, 2 Sep 2022 15:13:51 +0200 Message-Id: <20220902131352.1586599-2-o.rempel@pengutronix.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220902131352.1586599-1-o.rempel@pengutronix.de> References: <20220902131352.1586599-1-o.rempel@pengutronix.de> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: ore@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-iio@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org If VREF pin is attached, we should use external VREF source instead of the internal. Otherwise we will get wrong measurements on some of channel types. Signed-off-by: Oleksij Rempel --- changes v4: - use vref_reg pointer instead of bool use_internal_vref - move regulator registration to a separate function - rework error handling - add devm_add_action_or_reset --- drivers/iio/adc/ti-tsc2046.c | 54 ++++++++++++++++++++++++++++++++++-- 1 file changed, 52 insertions(+), 2 deletions(-) diff --git a/drivers/iio/adc/ti-tsc2046.c b/drivers/iio/adc/ti-tsc2046.c index 0d9436a69cbfb..5f92754e066be 100644 --- a/drivers/iio/adc/ti-tsc2046.c +++ b/drivers/iio/adc/ti-tsc2046.c @@ -8,6 +8,7 @@ #include #include #include +#include #include #include @@ -175,6 +176,8 @@ struct tsc2046_adc_priv { u32 time_per_bit_ns; struct tsc2046_adc_ch_cfg ch_cfg[TI_TSC2046_MAX_CHAN]; + unsigned int vref_mv; + struct regulator *vref_reg; }; #define TI_TSC2046_V_CHAN(index, bits, name) \ @@ -252,7 +255,9 @@ static u8 tsc2046_adc_get_cmd(struct tsc2046_adc_priv *priv, int ch_idx, case TI_TSC2046_ADDR_AUX: case TI_TSC2046_ADDR_VBAT: case TI_TSC2046_ADDR_TEMP0: - pd |= TI_TSC2046_SER | TI_TSC2046_PD1_VREF_ON; + pd |= TI_TSC2046_SER; + if (!priv->vref_reg) + pd |= TI_TSC2046_PD1_VREF_ON; } return TI_TSC2046_START | FIELD_PREP(TI_TSC2046_ADDR, ch_idx) | pd; @@ -468,7 +473,7 @@ static int tsc2046_adc_read_raw(struct iio_dev *indio_dev, * So, it is better to use external voltage-divider driver * instead, which is calculating complete chain. */ - *val = TI_TSC2046_INT_VREF; + *val = priv->vref_mv; *val2 = chan->scan_type.realbits; return IIO_VAL_FRACTIONAL_LOG2; } @@ -740,6 +745,47 @@ static void tsc2046_adc_parse_fwnode(struct tsc2046_adc_priv *priv) } } +static void tsc2046_adc_regulator_disable(void *data) +{ + struct tsc2046_adc_priv *priv = data; + + regulator_disable(priv->vref_reg); +} + +static int tsc2046_adc_configure_regulator(struct tsc2046_adc_priv *priv) +{ + struct device *dev = &priv->spi->dev; + int ret; + + priv->vref_reg = devm_regulator_get_optional(dev, "vref"); + if (IS_ERR(priv->vref_reg) && PTR_ERR(priv->vref_reg) != -ENODEV) + return PTR_ERR(priv->vref_reg); + + if (IS_ERR_OR_NULL(priv->vref_reg)) { + priv->vref_reg = NULL; + /* Use internal reference */ + priv->vref_mv = TI_TSC2046_INT_VREF; + return 0; + } + + ret = regulator_enable(priv->vref_reg); + if (ret) + return ret; + + ret = devm_add_action_or_reset(dev, tsc2046_adc_regulator_disable, + priv); + if (ret) + return ret; + + ret = regulator_get_voltage(priv->vref_reg); + if (ret < 0) + return ret; + + priv->vref_mv = ret / 1000; + + return 0; +} + static int tsc2046_adc_probe(struct spi_device *spi) { const struct tsc2046_adc_dcfg *dcfg; @@ -781,6 +827,10 @@ static int tsc2046_adc_probe(struct spi_device *spi) indio_dev->num_channels = dcfg->num_channels; indio_dev->info = &tsc2046_adc_info; + ret = tsc2046_adc_configure_regulator(priv); + if (ret) + return ret; + tsc2046_adc_parse_fwnode(priv); ret = tsc2046_adc_setup_spi_msg(priv);