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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham 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 735CAECDFB3 for ; Tue, 17 Jul 2018 21:00:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1294F20693 for ; Tue, 17 Jul 2018 21:00:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1294F20693 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=shmanahar.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731023AbeGQVek (ORCPT ); Tue, 17 Jul 2018 17:34:40 -0400 Received: from avasout05.plus.net ([84.93.230.250]:46554 "EHLO avasout05.plus.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729728AbeGQVej (ORCPT ); Tue, 17 Jul 2018 17:34:39 -0400 Received: from hairyalien ([80.229.148.18]) by smtp with SMTP id fX4nf0w0k05ijfX4ofF3fE; Tue, 17 Jul 2018 22:00:12 +0100 X-CM-Score: 0.00 X-CNFS-Analysis: v=2.3 cv=QJJGuDDL c=1 sm=1 tr=0 a=o7Djd4SkmPXITDn8qH+ssQ==:117 a=o7Djd4SkmPXITDn8qH+ssQ==:17 a=IkcTkHD0fZMA:10 a=R9QF1RCXAYgA:10 a=pGLkceISAAAA:8 a=NEAV23lmAAAA:8 a=6TZtSGDV1qYMrcTs3qQA:9 a=nMnXHCmPwxmY64QX:21 a=kPstQwhks1Tn8aqv:21 a=QEXdDO2ut3YA:10 Received: by hairyalien (sSMTP sendmail emulation); Tue, 17 Jul 2018 22:00:05 +0100 Date: Tue, 17 Jul 2018 22:00:05 +0100 From: Nick Dyer To: =?utf-8?B?UGF3ZcWC?= Chmiel Cc: dmitry.torokhov@gmail.com, robh+dt@kernel.org, mark.rutland@arm.com, nicolas.ferre@microchip.com, alexandre.belloni@bootlin.com, linux-input@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/2] Input: atmel_mxt_ts: Add support for optional regulators. Message-ID: <20180717210005.GA21416@hairyalien> References: <1531851386-17840-1-git-send-email-pawel.mikolaj.chmiel@gmail.com> <1531851386-17840-2-git-send-email-pawel.mikolaj.chmiel@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1531851386-17840-2-git-send-email-pawel.mikolaj.chmiel@gmail.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-CMAE-Envelope: MS4wfBnGOlP2wV8Hd5/1i2glJlyVzj4k10NHH6g5g9hZuijbXArqkYfx/oLqKX9xt9esOhJb87EiYHPctvT8mTLV0qtsZLfC738ou5ivZaRKMlKpSBGQYW8l qfJBGYCz9VNX0rnaasi7JCzgdeuTlqcXAhk= Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 17, 2018 at 08:16:25PM +0200, Paweł Chmiel wrote: > This patch adds optional regulators, which can be used to power > up touchscreen. After enabling regulators, we need to wait 150msec. > This value is taken from official driver. > > It was tested on Samsung Galaxy i9000 (based on Samsung S5PV210 SOC). > > Signed-off-by: Paweł Chmiel > --- > Changes from v1: > - Enable regulators only if reset_gpio is present. > - Switch from devm_regulator_get_optional to devm_regulator_get > --- > drivers/input/touchscreen/atmel_mxt_ts.c | 46 ++++++++++++++++++++++++++++++-- > 1 file changed, 44 insertions(+), 2 deletions(-) > > diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c > index 54fe190fd4bc..005f0fee9fc8 100644 > --- a/drivers/input/touchscreen/atmel_mxt_ts.c > +++ b/drivers/input/touchscreen/atmel_mxt_ts.c > @@ -27,6 +27,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -194,10 +195,10 @@ enum t100_type { > > /* Delay times */ > #define MXT_BACKUP_TIME 50 /* msec */ > -#define MXT_RESET_GPIO_TIME 20 /* msec */ > #define MXT_RESET_INVALID_CHG 100 /* msec */ > #define MXT_RESET_TIME 200 /* msec */ > #define MXT_RESET_TIMEOUT 3000 /* msec */ > +#define MXT_REGULATOR_DELAY 150 /* msec */ > #define MXT_CRC_TIMEOUT 1000 /* msec */ > #define MXT_FW_RESET_TIME 3000 /* msec */ > #define MXT_FW_CHG_TIMEOUT 300 /* msec */ > @@ -310,6 +311,8 @@ struct mxt_data { > struct t7_config t7_cfg; > struct mxt_dbg dbg; > struct gpio_desc *reset_gpio; > + struct regulator *vdd_reg; > + struct regulator *avdd_reg; > > /* Cached parameters from object table */ > u16 T5_address; > @@ -3076,6 +3079,22 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id) > return error; > } > > + data->vdd_reg = devm_regulator_get(&client->dev, "vdd"); > + if (IS_ERR(data->vdd_reg)) { > + error = PTR_ERR(data->vdd_reg); > + dev_err(&client->dev, "Failed to get vdd regulator: %d\n", > + error); > + return error; > + } > + > + data->avdd_reg = devm_regulator_get(&client->dev, "avdd"); > + if (IS_ERR(data->avdd_reg)) { > + error = PTR_ERR(data->avdd_reg); > + dev_err(&client->dev, "Failed to get avdd regulator: %d\n", > + error); > + return error; > + } > + > error = devm_request_threaded_irq(&client->dev, client->irq, > NULL, mxt_interrupt, IRQF_ONESHOT, > client->name, data); > @@ -3087,7 +3106,26 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id) > disable_irq(client->irq); > > if (data->reset_gpio) { > - msleep(MXT_RESET_GPIO_TIME); > + error = regulator_enable(data->vdd_reg); > + if (error) { > + dev_err(&client->dev, "Failed to enable vdd regulator: %d\n", > + error); > + return error; > + } > + > + error = regulator_enable(data->avdd_reg); > + if (error) { > + dev_err(&client->dev, "Failed to enable avdd regulator: %d\n", > + error); > + return error; > + } > + > + /* > + * According to maXTouch power sequencing specification, RESET line > + * must be kept low until some time after regulators come up to > + * voltage > + */ > + msleep(MXT_REGULATOR_DELAY); > gpiod_set_value(data->reset_gpio, 1); > msleep(MXT_RESET_INVALID_CHG); Hi Pawel- I see you've borrowed some of the logic from the patch I wrote a while back (see https://github.com/ndyer/linux/commit/8e9687e41ed062 ) The correct behaviour according to Atmel should be: * Make RESET zero * Bring up regulators * Wait for a period to settle (150 msec) * Release RESET * Wait for 100 msec whilst device gets through bootloader * Wait for CHG line assert before reading info block I can't see the first and last steps in your patch at present. The only downside with this approach is that there are a lot of delays during driver probe, but I believe the asynchronous probe stuff that's landed since I wrote the original patch should address that. cheers Nick > } > @@ -3116,6 +3154,10 @@ static int mxt_remove(struct i2c_client *client) > struct mxt_data *data = i2c_get_clientdata(client); > > disable_irq(data->irq); > + if (data->reset_gpio) { > + regulator_disable(data->avdd_reg); > + regulator_disable(data->vdd_reg); > + } > sysfs_remove_group(&client->dev.kobj, &mxt_attr_group); > mxt_free_input_device(data); > mxt_free_object_table(data); > -- > 2.7.4 >