From patchwork Wed Apr 16 23:12:29 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 4004521 Return-Path: X-Original-To: patchwork-linux-samsung-soc@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id CE3349F2BA for ; Wed, 16 Apr 2014 23:16:30 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id D90CB201BF for ; Wed, 16 Apr 2014 23:16:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B70C82017B for ; Wed, 16 Apr 2014 23:16:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756024AbaDPXNs (ORCPT ); Wed, 16 Apr 2014 19:13:48 -0400 Received: from mail-qc0-f201.google.com ([209.85.216.201]:52781 "EHLO mail-qc0-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757033AbaDPXMv (ORCPT ); Wed, 16 Apr 2014 19:12:51 -0400 Received: by mail-qc0-f201.google.com with SMTP id c9so1725934qcz.2 for ; Wed, 16 Apr 2014 16:12:50 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=qSd3WiUm8n3jICH2+Qc4aXRAkDME+IrQ87QOZmLgZ3k=; b=FTS1+SdiSyDsZAKIajCgKkrHrIfpYI8mLiSSUKopsAymFOaOAXedivI3dUdTPXoXQi CqfturxU9upR7ZqhfAqVEPJ68YbSoUBsO3QCwcdjpgHQIn32n37Oe9guI7I94M4Fp6T1 0/FwN/XtFoZhyMB0cRWeVGPJILtEZsQLuudCjbmMv3AzldtZGZ5VQ+ah4p1Q/j0RgGuB h47HwmqEmJnu90QXcyqFzojC+npz8nJtxB3uZRmGZJOpRC9wjCpe+dZ1GVg5SQd6tBqK LJKwSGS5ZRPDvio+8Ic0YS0/lNkUIsvgqdFdHTvKghyr13v3GIPU/jDd51P5QfDC2gsQ 8cPg== X-Gm-Message-State: ALoCoQlspTGSDeaKjtSw22NRqlQn8RUDOCIUgc5RckbicQEfxtJFx/Uipie/LK8Qo8aCx4qP4B+KCtPG1M6Uxmj9hukRa7dyVAzM74KyvUEfy12okJCZNWyiGu2r+GYe3vxFlWHujoQF1ok9yZwssutTKiVIR6sM1KTFiD86RRdSnqD85cliaaCioDwXgiBbKE3zis9RLbABzSKgr1ILAyNjq9xQZn0UhQ== X-Received: by 10.58.22.70 with SMTP id b6mr5548125vef.13.1397689970335; Wed, 16 Apr 2014 16:12:50 -0700 (PDT) Received: from corp2gmr1-2.hot.corp.google.com (corp2gmr1-2.hot.corp.google.com [172.24.189.93]) by gmr-mx.google.com with ESMTPS id e40si3305587yhf.0.2014.04.16.16.12.50 for (version=TLSv1.1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 16 Apr 2014 16:12:50 -0700 (PDT) Received: from tictac.mtv.corp.google.com (tictac.mtv.corp.google.com [172.22.72.141]) by corp2gmr1-2.hot.corp.google.com (Postfix) with ESMTP id 1F9945A4282; Wed, 16 Apr 2014 16:12:50 -0700 (PDT) Received: by tictac.mtv.corp.google.com (Postfix, from userid 121310) id C930880655; Wed, 16 Apr 2014 16:12:49 -0700 (PDT) From: Doug Anderson To: Anton Vorontsov Cc: Olof Johansson , Sachin Kamat , ajaykumar.rs@samsung.com, linux-samsung-soc@vger.kernel.org, Doug Anderson , Simon Glass , Michael Spang , Sean Paul , Liam Girdwood , Mark Brown , linux-kernel@vger.kernel.org Subject: [PATCH v3 5/5] regulator: tps65090: Make FETs more reliable by adding retries Date: Wed, 16 Apr 2014 16:12:29 -0700 Message-Id: <1397689950-1568-6-git-send-email-dianders@chromium.org> X-Mailer: git-send-email 1.9.1.423.g4596e3a In-Reply-To: <1397689950-1568-1-git-send-email-dianders@chromium.org> References: <1397689950-1568-1-git-send-email-dianders@chromium.org> Sender: linux-samsung-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@vger.kernel.org X-Spam-Status: No, score=-7.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP An issue was discovered with tps65090 where sometimes the FETs wouldn't actually turn on when requested (they would report overcurrent). The most problematic FET was the one used for the LCD backlight on the Samsung ARM Chromebook (FET1). Problems were especially prevalent when the device was plugged in to AC power (when the backlight voltage was higher). Mitigate the problem by adding retries on the enables of the FETs, which works around the problem fairly effectively. Signed-off-by: Doug Anderson Signed-off-by: Simon Glass Signed-off-by: Michael Spang Signed-off-by: Sean Paul Reviewed-by: Simon Glass --- Changes in v3: - Fixed kernel-doc notation for return Changes in v2: - Separated the overcurrent and retries changes into two patches. - No longer open code fet_is_enabled(). - Fixed tps6090 typo. - For loop => "while true". - Removed a set of braces. drivers/regulator/tps65090-regulator.c | 155 +++++++++++++++++++++++++++++---- 1 file changed, 140 insertions(+), 15 deletions(-) diff --git a/drivers/regulator/tps65090-regulator.c b/drivers/regulator/tps65090-regulator.c index ca04e9f..2057e2e 100644 --- a/drivers/regulator/tps65090-regulator.c +++ b/drivers/regulator/tps65090-regulator.c @@ -17,6 +17,7 @@ */ #include +#include #include #include #include @@ -28,7 +29,13 @@ #include #include +#define MAX_CTRL_READ_TRIES 5 +#define MAX_FET_ENABLE_TRIES 1000 + +#define CTRL_EN_BIT 0 /* Regulator enable bit, active high */ #define CTRL_WT_BIT 2 /* Regulator wait time 0 bit */ +#define CTRL_PG_BIT 4 /* Regulator power good bit, 1=good */ +#define CTRL_TO_BIT 7 /* Regulator timeout bit, 1=wait */ #define MAX_OVERCURRENT_WAIT 3 /* Overcurrent wait must be <= this */ @@ -80,40 +87,158 @@ static int tps65090_reg_set_overcurrent_wait(struct tps65090_regulator *ri, return ret; } -static struct regulator_ops tps65090_reg_contol_ops = { +/** + * tps65090_try_enable_fet - Try to enable a FET + * + * @rdev: Regulator device + * + * Return: 0 if ok, -ENOTRECOVERABLE if the FET power good bit did not get + * set, or some other -ve value if another error occurred (e.g. i2c error) + */ +static int tps65090_try_enable_fet(struct regulator_dev *rdev) +{ + unsigned int control; + int ret, i; + + ret = regmap_update_bits(rdev->regmap, rdev->desc->enable_reg, + rdev->desc->enable_mask, + rdev->desc->enable_mask); + if (ret < 0) { + dev_err(&rdev->dev, "Error in updating reg %#x\n", + rdev->desc->enable_reg); + return ret; + } + + for (i = 0; i < MAX_CTRL_READ_TRIES; i++) { + ret = regmap_read(rdev->regmap, rdev->desc->enable_reg, + &control); + if (ret < 0) + return ret; + + if (!(control & BIT(CTRL_TO_BIT))) + break; + + usleep_range(1000, 1500); + } + if (!(control & BIT(CTRL_PG_BIT))) + return -ENOTRECOVERABLE; + + return 0; +} + +/** + * tps65090_fet_enable - Enable a FET, trying a few times if it fails + * + * Some versions of the tps65090 have issues when turning on the FETs. + * This function goes through several steps to ensure the best chance of the + * FET going on. Specifically: + * - We'll make sure that we bump the "overcurrent wait" to the maximum, which + * increases the chances that we'll turn on properly. + * - We'll retry turning the FET on multiple times (turning off in between). + * + * @rdev: Regulator device + * + * Return: 0 if ok, non-zero if it fails. + */ +static int tps65090_fet_enable(struct regulator_dev *rdev) +{ + int ret, tries; + + /* + * Try enabling multiple times until we succeed since sometimes the + * first try times out. + */ + tries = 0; + while (true) { + ret = tps65090_try_enable_fet(rdev); + if (!ret) + break; + if (ret != -ENOTRECOVERABLE || tries == MAX_FET_ENABLE_TRIES) + goto err; + + /* Try turning the FET off (and then on again) */ + ret = regmap_update_bits(rdev->regmap, rdev->desc->enable_reg, + rdev->desc->enable_mask, 0); + if (ret) + goto err; + + tries++; + } + + if (tries) + dev_warn(&rdev->dev, "reg %#x enable ok after %d tries\n", + rdev->desc->enable_reg, tries); + + return 0; +err: + dev_warn(&rdev->dev, "reg %#x enable failed\n", rdev->desc->enable_reg); + WARN_ON(1); + + return ret; +} + +static struct regulator_ops tps65090_reg_control_ops = { .enable = regulator_enable_regmap, .disable = regulator_disable_regmap, .is_enabled = regulator_is_enabled_regmap, }; +static struct regulator_ops tps65090_fet_control_ops = { + .enable = tps65090_fet_enable, + .disable = regulator_disable_regmap, + .is_enabled = regulator_is_enabled_regmap, +}; + static struct regulator_ops tps65090_ldo_ops = { }; -#define tps65090_REG_DESC(_id, _sname, _en_reg, _ops) \ +#define tps65090_REG_DESC(_id, _sname, _en_reg, _en_bits, _ops) \ { \ .name = "TPS65090_RAILS"#_id, \ .supply_name = _sname, \ .id = TPS65090_REGULATOR_##_id, \ .ops = &_ops, \ .enable_reg = _en_reg, \ - .enable_mask = BIT(0), \ + .enable_val = _en_bits, \ + .enable_mask = _en_bits, \ .type = REGULATOR_VOLTAGE, \ .owner = THIS_MODULE, \ } static struct regulator_desc tps65090_regulator_desc[] = { - tps65090_REG_DESC(DCDC1, "vsys1", 0x0C, tps65090_reg_contol_ops), - tps65090_REG_DESC(DCDC2, "vsys2", 0x0D, tps65090_reg_contol_ops), - tps65090_REG_DESC(DCDC3, "vsys3", 0x0E, tps65090_reg_contol_ops), - tps65090_REG_DESC(FET1, "infet1", 0x0F, tps65090_reg_contol_ops), - tps65090_REG_DESC(FET2, "infet2", 0x10, tps65090_reg_contol_ops), - tps65090_REG_DESC(FET3, "infet3", 0x11, tps65090_reg_contol_ops), - tps65090_REG_DESC(FET4, "infet4", 0x12, tps65090_reg_contol_ops), - tps65090_REG_DESC(FET5, "infet5", 0x13, tps65090_reg_contol_ops), - tps65090_REG_DESC(FET6, "infet6", 0x14, tps65090_reg_contol_ops), - tps65090_REG_DESC(FET7, "infet7", 0x15, tps65090_reg_contol_ops), - tps65090_REG_DESC(LDO1, "vsys-l1", 0, tps65090_ldo_ops), - tps65090_REG_DESC(LDO2, "vsys-l2", 0, tps65090_ldo_ops), + tps65090_REG_DESC(DCDC1, "vsys1", 0x0C, BIT(CTRL_EN_BIT), + tps65090_reg_control_ops), + tps65090_REG_DESC(DCDC2, "vsys2", 0x0D, BIT(CTRL_EN_BIT), + tps65090_reg_control_ops), + tps65090_REG_DESC(DCDC3, "vsys3", 0x0E, BIT(CTRL_EN_BIT), + tps65090_reg_control_ops), + + tps65090_REG_DESC(FET1, "infet1", 0x0F, + BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT), + tps65090_fet_control_ops), + tps65090_REG_DESC(FET2, "infet2", 0x10, + BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT), + tps65090_fet_control_ops), + tps65090_REG_DESC(FET3, "infet3", 0x11, + BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT), + tps65090_fet_control_ops), + tps65090_REG_DESC(FET4, "infet4", 0x12, + BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT), + tps65090_fet_control_ops), + tps65090_REG_DESC(FET5, "infet5", 0x13, + BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT), + tps65090_fet_control_ops), + tps65090_REG_DESC(FET6, "infet6", 0x14, + BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT), + tps65090_fet_control_ops), + tps65090_REG_DESC(FET7, "infet7", 0x15, + BIT(CTRL_EN_BIT) | BIT(CTRL_PG_BIT), + tps65090_fet_control_ops), + + tps65090_REG_DESC(LDO1, "vsys-l1", 0, 0, + tps65090_ldo_ops), + tps65090_REG_DESC(LDO2, "vsys-l2", 0, 0, + tps65090_ldo_ops), }; static inline bool is_dcdc(int id)