From patchwork Thu Mar 16 16:47:03 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Bara X-Patchwork-Id: 1757956 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=2620:137:e000::1:20; helo=out1.vger.email; envelope-from=linux-tegra-owner@vger.kernel.org; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20210112 header.b=o1Imx258; dkim-atps=neutral Received: from out1.vger.email (out1.vger.email [IPv6:2620:137:e000::1:20]) by legolas.ozlabs.org (Postfix) with ESMTP id 4PctTc2BFjz1yWs for ; Fri, 17 Mar 2023 03:47:16 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230378AbjCPQrN (ORCPT ); Thu, 16 Mar 2023 12:47:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41044 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229733AbjCPQrN (ORCPT ); Thu, 16 Mar 2023 12:47:13 -0400 Received: from mail-wr1-x429.google.com (mail-wr1-x429.google.com [IPv6:2a00:1450:4864:20::429]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DDAD2227A0; Thu, 16 Mar 2023 09:47:11 -0700 (PDT) Received: by mail-wr1-x429.google.com with SMTP id m2so2128461wrh.6; Thu, 16 Mar 2023 09:47:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1678985230; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=sL7v6vWIbKHGctooUHR0HwyGIzabAjFcG5L+GNX/WqE=; b=o1Imx2584lNwRwvD/3BzpcRNmMHJFUOWQPVGk9rgiuci7WNnqxW/qsUSIB59E7a8KS /0f1LWhkCG4NxTMR4FF5ZC4uzUl7ztWaIh7AsCbfdI8+to154kOxtLxkuJO91eWRtc/B 8EC4XSDkPTwGzLY7/s2v3Mb5Iq040mQvTuup11ae4RemtKkGE7wDsIAoeCdaI5Sgz3UY QyZKkVGjIPP0gWxTjTPZIaGQnPK+euhFc96eR9ZInXwZlyzV8U/EgccXL6OvLuKjL9a6 a51AwaMoQlRpMVVHwRCt4P0nKo0WUS0XIpBa4N8cCfzuCK/LpTVFHinfZWaRb2U3fss6 66Aw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678985230; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=sL7v6vWIbKHGctooUHR0HwyGIzabAjFcG5L+GNX/WqE=; b=BaUTUUCxlw++6HISpBgBibvkW3oauWj3nx+YGNB0ehvfG/4cQsd/qE91qtgQEfPEiz H1ATGbRQwQuRlPrpnn+nmqS7eoU5gZZ8HLHGPlGK+yx/U70VMzTUH2waAcNEymjXWfK9 A2ebFvsZygHJ3oOh4shQ6QSKlXXDPJ+ZglshCP7IBY/he5hYOyWCUgV4U6sUDmy67Jwb 10qq5MrAhR87XHnYI3cRXIx1jd0R0C/3lW8B98HCxctSb88ZYqm53KFcN7Cewj8gBajU wsgXj2RX8BN1DA/qhqVhuYttpAcNrhRBsKASj6/fOL4ZidUrNiqQHYLCwTS5dRUY8Xxq 2UHg== X-Gm-Message-State: AO0yUKWl+EZ91LhOG1QsITphOyhuS+v4bBgYk1wSE5Sa7UAoObXdf4Ee DLQ41tgFSLxxHlkDAV1CDK4= X-Google-Smtp-Source: AK7set/7pRkmYqkQ59KzvnaR/T7KBxU7LRrTZNImnqqh0kv8hXZ95qwJuwTdLcwObFxls5T3GK9lbw== X-Received: by 2002:a5d:534e:0:b0:2cf:f04b:fb23 with SMTP id t14-20020a5d534e000000b002cff04bfb23mr5121220wrv.59.1678985229966; Thu, 16 Mar 2023 09:47:09 -0700 (PDT) Received: from PCBABN.skidata.net ([91.230.2.244]) by smtp.gmail.com with ESMTPSA id l10-20020a5d560a000000b002cfeffb442bsm5754352wrv.57.2023.03.16.09.47.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 16 Mar 2023 09:47:09 -0700 (PDT) From: Benjamin Bara To: lee@kernel.org Cc: digetx@gmail.com, jonathanh@nvidia.com, treding@nvidia.com, richard.leitner@linux.dev, benjamin.bara@skidata.com, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] mfd: tps6586x: register restart handler Date: Thu, 16 Mar 2023 17:47:03 +0100 Message-Id: <20230316164703.1157813-1-bbara93@gmail.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 X-Spam-Status: No, score=-1.8 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_ENVFROM_END_DIGIT, FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-tegra@vger.kernel.org From: Benjamin Bara The TPS658629-Q1 (unfortunately the only TPS6586x with public data sheet) provides a SOFT RST bit in the SUPPLYENE reg to request a (cold) reboot. Use it to implement and register a restart handler/notifier. The DS does not clarify if only writing the SOFT RST bit has side effects. Therefore, regmap_update_bits() is used. Set an appropriate system_state and disable the IRQs to activate i2c_in_atomic_xfer_mode(). This avoids the following WARNING: [ 12.667612] WARNING: CPU: 1 PID: 1 at kernel/rcu/tree_plugin.h:318 rcu_note_context_switch+0x33c/0x6b0 [ 12.676926] Voluntary context switch within RCU read-side critical section! ... [ 12.742376] schedule_timeout from wait_for_completion_timeout+0x90/0x114 [ 12.749179] wait_for_completion_timeout from tegra_i2c_wait_completion+0x40/0x70 Tested on a TPS658640. Signed-off-by: Benjamin Bara --- drivers/mfd/tps6586x.c | 38 ++++++++++++++++++++++++++++++++++++-- 1 file changed, 36 insertions(+), 2 deletions(-) diff --git a/drivers/mfd/tps6586x.c b/drivers/mfd/tps6586x.c index 2d947f3f606a..e40c664b5f64 100644 --- a/drivers/mfd/tps6586x.c +++ b/drivers/mfd/tps6586x.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -22,6 +23,7 @@ #include #include #include +#include #include #include @@ -29,6 +31,7 @@ #include #define TPS6586X_SUPPLYENE 0x14 +#define SOFT_RST_BIT BIT(0) #define EXITSLREQ_BIT BIT(1) #define SLEEP_MODE_BIT BIT(3) @@ -466,6 +469,23 @@ static void tps6586x_power_off(void) tps6586x_set_bits(tps6586x_dev, TPS6586X_SUPPLYENE, SLEEP_MODE_BIT); } +static int tps6586x_restart_notify(struct notifier_block *this, unsigned long mode, void *data) +{ + /* bring pmic into HARD REBOOT state, disable IRQs for atomic i2c RCU */ + system_state = SYSTEM_RESTART; + local_irq_disable(); + tps6586x_set_bits(tps6586x_dev, TPS6586X_SUPPLYENE, SOFT_RST_BIT); + local_irq_enable(); + + mdelay(500); + return NOTIFY_DONE; +} + +static struct notifier_block tps6586x_restart_handler = { + .notifier_call = tps6586x_restart_notify, + .priority = 200, +}; + static void tps6586x_print_version(struct i2c_client *client, int version) { const char *name; @@ -559,9 +579,16 @@ static int tps6586x_i2c_probe(struct i2c_client *client) goto err_add_devs; } - if (pdata->pm_off && !pm_power_off) { + if (pdata->pm_off) { tps6586x_dev = &client->dev; - pm_power_off = tps6586x_power_off; + if (!pm_power_off) + pm_power_off = tps6586x_power_off; + + ret = register_restart_handler(&tps6586x_restart_handler); + if (ret) { + dev_err(&client->dev, "register restart handler failed: %d\n", ret); + goto err_add_devs; + } } return 0; @@ -582,6 +609,13 @@ static void tps6586x_i2c_remove(struct i2c_client *client) mfd_remove_devices(tps6586x->dev); if (client->irq) free_irq(client->irq, tps6586x); + + if (tps6586x_dev == &client->dev) { + tps6586x_dev = NULL; + unregister_restart_handler(&tps6586x_restart_handler); + if (pm_power_off == tps6586x_power_off) + pm_power_off = NULL; + } } static int __maybe_unused tps6586x_i2c_suspend(struct device *dev)