From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B1A9BC433DF for ; Tue, 19 May 2020 12:57:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 97FB42081A for ; Tue, 19 May 2020 12:57:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728887AbgESM5P (ORCPT ); Tue, 19 May 2020 08:57:15 -0400 Received: from mga05.intel.com ([192.55.52.43]:51738 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727057AbgESM5O (ORCPT ); Tue, 19 May 2020 08:57:14 -0400 IronPort-SDR: E2QBmr482Xm1x2Cte/j9hPGXZF5wmzhvMSGUe0h1yZ5/gchdZmHiNvOF20y7/nCXxy1O4TfSBL +hhPBBUjYeEw== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 May 2020 05:57:14 -0700 IronPort-SDR: IGesn6ruI9c5l9UBged3IFqb32A4loP7jb2lhNCucO5P8GEmlPgK4PCkSGnPK1V2I1zFXjC8f9 W4jeP7ggNFVw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,410,1583222400"; d="scan'208";a="373717845" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.40]) by fmsmga001.fm.intel.com with ESMTP; 19 May 2020 05:57:10 -0700 Received: from andy by smile with local (Exim 4.93) (envelope-from ) id 1jb1o1-007dbT-2d; Tue, 19 May 2020 15:57:13 +0300 Date: Tue, 19 May 2020 15:57:13 +0300 From: Andy Shevchenko To: Jonathan Albrieux Cc: linux-kernel@vger.kernel.org, ~postmarketos/upstreaming@lists.sr.ht, "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Greg Kroah-Hartman , Hartmut Knaack , Jilayne Lovejoy , Jonathan Cameron , Kate Stewart , Lars-Peter Clausen , Linus Walleij , "open list:IIO SUBSYSTEM AND DRIVERS" , Peter Meerwald-Stadler , Steve Winslow , Thomas Gleixner , Jonathan Cameron , Allison Randal Subject: Re: [PATCH v3 4/4] iio: magnetometer: ak8975: Add gpio reset support Message-ID: <20200519125713.GI1634618@smile.fi.intel.com> References: <20200519124402.26076-1-jonathan.albrieux@gmail.com> <20200519124402.26076-5-jonathan.albrieux@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200519124402.26076-5-jonathan.albrieux@gmail.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 19, 2020 at 02:43:54PM +0200, Jonathan Albrieux wrote: > According to AK09911 datasheet, if reset gpio is provided then > deassert reset on ak8975_power_on() and assert reset on ak8975_power_off(). > > Without reset's deassertion during ak8975_power_on(), driver's probe fails > on ak8975_who_i_am while() checking for device identity for AK09911 chip. Wrong position of (), but hold on, this is so minor, no need to send a new version because of this. > AK09911 has an active low reset gpio to handle register's reset. > AK09911 datasheed says that, if not used, reset pin should be connected > to VID. This patch emulates this situation. Reviewed-by: Andy Shevchenko > Signed-off-by: Jonathan Albrieux > --- > drivers/iio/magnetometer/ak8975.c | 18 ++++++++++++++++++ > 1 file changed, 18 insertions(+) > > diff --git a/drivers/iio/magnetometer/ak8975.c b/drivers/iio/magnetometer/ak8975.c > index fd368455cd7b..a23422aad97d 100644 > --- a/drivers/iio/magnetometer/ak8975.c > +++ b/drivers/iio/magnetometer/ak8975.c > @@ -358,6 +358,7 @@ struct ak8975_data { > u8 asa[3]; > long raw_to_gauss[3]; > struct gpio_desc *eoc_gpiod; > + struct gpio_desc *reset_gpiod; > int eoc_irq; > wait_queue_head_t data_ready_queue; > unsigned long flags; > @@ -384,6 +385,9 @@ static int ak8975_power_on(const struct ak8975_data *data) > "Failed to enable specified Vid supply\n"); > return ret; > } > + > + gpiod_set_value_cansleep(data->reset_gpiod, 0); > + > /* > * According to the datasheet the power supply rise time is 200us > * and the minimum wait time before mode setting is 100us, in > @@ -396,6 +400,8 @@ static int ak8975_power_on(const struct ak8975_data *data) > /* Disable attached power regulator if any. */ > static void ak8975_power_off(const struct ak8975_data *data) > { > + gpiod_set_value_cansleep(data->reset_gpiod, 1); > + > regulator_disable(data->vid); > regulator_disable(data->vdd); > } > @@ -839,6 +845,7 @@ static int ak8975_probe(struct i2c_client *client, > struct ak8975_data *data; > struct iio_dev *indio_dev; > struct gpio_desc *eoc_gpiod; > + struct gpio_desc *reset_gpiod; > const void *match; > unsigned int i; > int err; > @@ -856,6 +863,16 @@ static int ak8975_probe(struct i2c_client *client, > if (eoc_gpiod) > gpiod_set_consumer_name(eoc_gpiod, "ak_8975"); > > + /* > + * According to AK09911 datasheet, if reset GPIO is provided then > + * deassert reset on ak8975_power_on() and assert reset on > + * ak8975_power_off(). > + */ > + reset_gpiod = devm_gpiod_get_optional(&client->dev, > + "reset", GPIOD_OUT_HIGH); > + if (IS_ERR(reset_gpiod)) > + return PTR_ERR(reset_gpiod); > + > /* Register with IIO */ > indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); > if (indio_dev == NULL) > @@ -866,6 +883,7 @@ static int ak8975_probe(struct i2c_client *client, > > data->client = client; > data->eoc_gpiod = eoc_gpiod; > + data->reset_gpiod = reset_gpiod; > data->eoc_irq = 0; > > err = iio_read_mount_matrix(&client->dev, "mount-matrix", &data->orientation); > -- > 2.17.1 > -- With Best Regards, Andy Shevchenko