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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3489CC433F5 for ; Tue, 28 Sep 2021 13:33:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1BAD760FF2 for ; Tue, 28 Sep 2021 13:33:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241269AbhI1Nee (ORCPT ); Tue, 28 Sep 2021 09:34:34 -0400 Received: from relay3-d.mail.gandi.net ([217.70.183.195]:46605 "EHLO relay3-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241142AbhI1NeW (ORCPT ); Tue, 28 Sep 2021 09:34:22 -0400 Received: (Authenticated sender: miquel.raynal@bootlin.com) by relay3-d.mail.gandi.net (Postfix) with ESMTPSA id 5C5586000C; Tue, 28 Sep 2021 13:32:40 +0000 (UTC) From: Miquel Raynal To: Jonathan Cameron , Lars-Peter Clausen , Lee Jones Cc: Peter Meerwald-Stadler , Rob Herring , Dmitry Torokhov , bcousson@baylibre.com, Tony Lindgren , linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-omap@vger.kernel.org, Thomas Petazzoni , Vignesh Raghavendra , Lokesh Vutla , Tero Kristo , Ryan Barnett , Grygorii Strashko , Jason Reeder , , Miquel Raynal , Jonathan Cameron Subject: [PATCH v4 21/48] mfd: ti_am335x_tscadc: Reorder the initialization steps Date: Tue, 28 Sep 2021 15:31:16 +0200 Message-Id: <20210928133143.157329-22-miquel.raynal@bootlin.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20210928133143.157329-1-miquel.raynal@bootlin.com> References: <20210928133143.157329-1-miquel.raynal@bootlin.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org TI AM335X TRM [1] states that most of the configuration should be set in the control register in the first place, before actually enabling the hardware with the subsystem enable bit. So far only half of the configuration was made in the first step (before enabling the "subsystem"), which does not make really sense. Also, the probe and the resume patch were acting differently. Let's harmonize all this by following these steps: 1/ Configure the CLKDIV register 2/ Configure the CTRL register 3/ Configure the idle configuration 4/ Really enable the device by rewriting the CTRL register with the subsystem enable bit set. [1] https://www.ti.com/lit/pdf/spruh73 Signed-off-by: Miquel Raynal Reviewed-by: Jonathan Cameron --- drivers/mfd/ti_am335x_tscadc.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c index d1f70224e457..01c2b7d1c18c 100644 --- a/drivers/mfd/ti_am335x_tscadc.c +++ b/drivers/mfd/ti_am335x_tscadc.c @@ -219,8 +219,6 @@ static int ti_tscadc_probe(struct platform_device *pdev) /* Set the control register bits */ ctrl = CNTRLREG_STEPCONFIGWRT | CNTRLREG_STEPID; - regmap_write(tscadc->regmap, REG_CTRL, ctrl); - if (tsc_wires > 0) { tscadc->tsc_wires = tsc_wires; if (tsc_wires == 5) @@ -228,6 +226,7 @@ static int ti_tscadc_probe(struct platform_device *pdev) else ctrl |= CNTRLREG_4WIRE | CNTRLREG_TSCENB; } + regmap_write(tscadc->regmap, REG_CTRL, ctrl); tscadc_idle_config(tscadc); @@ -313,9 +312,9 @@ static int __maybe_unused tscadc_resume(struct device *dev) pm_runtime_get_sync(dev); /* context restore */ - ctrl = CNTRLREG_STEPCONFIGWRT | CNTRLREG_STEPID; - regmap_write(tscadc->regmap, REG_CTRL, ctrl); + regmap_write(tscadc->regmap, REG_CLKDIV, tscadc->clk_div); + ctrl = CNTRLREG_STEPCONFIGWRT | CNTRLREG_STEPID; if (tscadc->tsc_wires > 0) { if (tscadc->tsc_wires == 5) ctrl |= CNTRLREG_5WIRE | CNTRLREG_TSCENB; @@ -323,13 +322,13 @@ static int __maybe_unused tscadc_resume(struct device *dev) ctrl |= CNTRLREG_4WIRE | CNTRLREG_TSCENB; } + regmap_write(tscadc->regmap, REG_CTRL, ctrl); + tscadc_idle_config(tscadc); ctrl |= CNTRLREG_TSCSSENB; regmap_write(tscadc->regmap, REG_CTRL, ctrl); - regmap_write(tscadc->regmap, REG_CLKDIV, tscadc->clk_div); - return 0; } -- 2.27.0