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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 C3899C7618B for ; Thu, 25 Jul 2019 09:46:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8F8C62190F for ; Thu, 25 Jul 2019 09:46:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390800AbfGYJqG (ORCPT ); Thu, 25 Jul 2019 05:46:06 -0400 Received: from relay2-d.mail.gandi.net ([217.70.183.194]:46217 "EHLO relay2-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729162AbfGYJqC (ORCPT ); Thu, 25 Jul 2019 05:46:02 -0400 X-Originating-IP: 92.137.69.152 Received: from localhost (alyon-656-1-672-152.w92-137.abo.wanadoo.fr [92.137.69.152]) (Authenticated sender: gregory.clement@bootlin.com) by relay2-d.mail.gandi.net (Postfix) with ESMTPSA id ED6D040006; Thu, 25 Jul 2019 09:45:58 +0000 (UTC) From: Gregory CLEMENT To: Liam Girdwood , Mark Brown , linux-kernel@vger.kernel.org Cc: Rob Herring , devicetree@vger.kernel.org, Tony Lindgren , linux-omap@vger.kernel.org, Thomas Petazzoni , Gregory CLEMENT Subject: [PATCH 3/3] regulator: twl6030: workaround the VMMC reset behavior Date: Thu, 25 Jul 2019 11:45:42 +0200 Message-Id: <20190725094542.16547-4-gregory.clement@bootlin.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190725094542.16547-1-gregory.clement@bootlin.com> References: <20190725094542.16547-1-gregory.clement@bootlin.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org During reset the VMMC regulator doesn't reach 0V and only drops to 1.8V, furthermore the pulse width is under 200us whereas the SD specification expect 1ms. The WR_S bit allows the TWL6030 to no reset at all the VMMC during warm reset and keep the current voltage. Thanks to this workaround the SD card doesn't reach a undefined reset stage. Actually this behavior is available for all the LDO regulator, so the driver will also allow to use it with any of these regulator. Signed-off-by: Gregory CLEMENT --- drivers/regulator/twl6030-regulator.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/drivers/regulator/twl6030-regulator.c b/drivers/regulator/twl6030-regulator.c index d73c81542ceb..b8100c3cedad 100644 --- a/drivers/regulator/twl6030-regulator.c +++ b/drivers/regulator/twl6030-regulator.c @@ -57,6 +57,9 @@ struct twlreg_info { #define VREG_BC_PROC 3 #define VREG_BC_CLK_RST 4 +/* TWL6030 LDO register values for VREG_VOLTAGE */ +#define TWL6030_VREG_VOLTAGE_WR_S BIT(7) + /* TWL6030 LDO register values for CFG_STATE */ #define TWL6030_CFG_STATE_OFF 0x00 #define TWL6030_CFG_STATE_ON 0x01 @@ -68,9 +71,10 @@ struct twlreg_info { #define TWL6030_CFG_STATE_APP(v) (((v) & TWL6030_CFG_STATE_APP_MASK) >>\ TWL6030_CFG_STATE_APP_SHIFT) -/* Flags for SMPS Voltage reading */ +/* Flags for SMPS Voltage reading and LDO reading*/ #define SMPS_OFFSET_EN BIT(0) #define SMPS_EXTENDED_EN BIT(1) +#define TWL_6030_WARM_RESET BIT(3) /* twl6032 SMPS EPROM values */ #define TWL6030_SMPS_OFFSET 0xB0 @@ -250,6 +254,9 @@ twl6030ldo_set_voltage_sel(struct regulator_dev *rdev, unsigned selector) { struct twlreg_info *info = rdev_get_drvdata(rdev); + if (info->flags & TWL_6030_WARM_RESET) + selector |= TWL6030_VREG_VOLTAGE_WR_S; + return twlreg_write(info, TWL_MODULE_PM_RECEIVER, VREG_VOLTAGE, selector); } @@ -259,6 +266,9 @@ static int twl6030ldo_get_voltage_sel(struct regulator_dev *rdev) struct twlreg_info *info = rdev_get_drvdata(rdev); int vsel = twlreg_read(info, TWL_MODULE_PM_RECEIVER, VREG_VOLTAGE); + if (info->flags & TWL_6030_WARM_RESET) + vsel &= ~TWL6030_VREG_VOLTAGE_WR_S; + return vsel; } @@ -710,6 +720,9 @@ static int twlreg_probe(struct platform_device *pdev) break; } + if (of_get_property(np, "ti,retain-on-reset", NULL)) + info->flags |= TWL_6030_WARM_RESET; + config.dev = &pdev->dev; config.init_data = initdata; config.driver_data = info; -- 2.20.1