From patchwork Thu May 29 08:28:05 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andreas Fenkart X-Patchwork-Id: 4263121 Return-Path: X-Original-To: patchwork-linux-mmc@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 D164C9F1E7 for ; Thu, 29 May 2014 08:30:14 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 023FE2026C for ; Thu, 29 May 2014 08:30:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3581F201C7 for ; Thu, 29 May 2014 08:30:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932431AbaE2IaK (ORCPT ); Thu, 29 May 2014 04:30:10 -0400 Received: from mail-ob0-f174.google.com ([209.85.214.174]:64766 "EHLO mail-ob0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755249AbaE2IaJ (ORCPT ); Thu, 29 May 2014 04:30:09 -0400 Received: by mail-ob0-f174.google.com with SMTP id uz6so9757obc.5 for ; Thu, 29 May 2014 01:30:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=g8Hg5JDXnbXr5qedvBExI2sHSZZmix7TjyazB6jEx1c=; b=yTxIpjlD8UYkPywViMHDNGXFLcBXb7bFCSJcKueMq4JsswyepOiQMv/Ip4cZmAc7jb 8h/xQbP7RQLsBAhJdZVxfs57G9lrzkGWY6/JfTBBF8caKPeuZLkKY1F6A1KEMzAyUcE+ cKUYg300FMGvkGDwRBll1mAGp8wKi2LrsQda+mBgrg5GNiym7aznptjmBNyPr3XH2hFX 6Ntq4A0cdssmkcxCeZNeoDAScXuaNws4EKdQhGI9kKcWWO6Fo7b6N7jRQ0Ex3Za8MvZz LRMQtBjJIkrzZWtDX6DMxQ50XueAwVYyyp6V1CNHPerOV/dCbRaiYUlSIPMFBXyZvV9U QOQA== X-Received: by 10.60.173.228 with SMTP id bn4mr6273266oec.27.1401352208498; Thu, 29 May 2014 01:30:08 -0700 (PDT) Received: from localhost (ip-89-176-190-91.net.upcbroadband.cz. [89.176.190.91]) by mx.google.com with ESMTPSA id w9sm16721560obx.15.2014.05.29.01.30.04 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Thu, 29 May 2014 01:30:07 -0700 (PDT) From: Andreas Fenkart To: Tony Lindgren Cc: Chris Ball , Grant Likely , Felipe Balbi , Balaji T K , Andreas Mueller , Sebastian Reichel , zonque@gmail.com, galak@codeaurora.org, linux-doc@vger.kernel.org, linux-mmc@vger.kernel.org, linux-omap@vger.kernel.org, Andreas Fenkart Subject: [PATCH v14 6/6] mmc: omap_hsmmc: Pin remux workaround to support SDIO interrupt on AM335x Date: Thu, 29 May 2014 10:28:05 +0200 Message-Id: <1401352085-22781-7-git-send-email-afenkart@gmail.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1401352085-22781-1-git-send-email-afenkart@gmail.com> References: <1401352085-22781-1-git-send-email-afenkart@gmail.com> Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org X-Spam-Status: No, score=-7.4 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, T_DKIM_INVALID, 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 The am335x can't detect pending cirq in PM runtime suspend. This patch reconfigures dat1 as a GPIO before going to suspend. SDIO interrupts are detected with the GPIO, the GPIO will only wake the module from suspend, SDIO irq detection will still happen through the IP block. Idea of remuxing the pins by Tony Lindgren. Code contributions from Tony Lindgren and Balaji T K Signed-off-by: Andreas Fenkart Signed-off-by: Tony Lindgren Acked-by: Balaji T K diff --git a/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt b/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt index 0233ba7..76bf087 100644 --- a/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt +++ b/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt @@ -57,3 +57,56 @@ Examples: &edma 25>; dma-names = "tx", "rx"; }; + +[workaround for missing swakeup on am33xx] + +This SOC is missing the swakeup line, it will not detect SDIO irq +while in suspend. + + ------ + | PRCM | + ------ + ^ | + swakeup | | fclk + | v + ------ ------- ----- + | card | -- CIRQ --> | hsmmc | -- IRQ --> | CPU | + ------ ------- ----- + +In suspend the fclk is off and the module is disfunctional. Even register reads +will fail. A small logic in the host will request fclk restore, when an +external event is detected. Once the clock is restored, the host detects the +event normally. Since am33xx doesn't have this line it never wakes from +suspend. + +The workaround is to reconfigure the dat1 line as a GPIO upon suspend. To make +this work, we need to set the named pinctrl states "default" and "idle". +Prepare idle to remux dat1 as a gpio, and default to remux it back as sdio +dat1. The MMC driver will then toggle between idle and default state during +runtime. + +In summary: +1. select matching 'compatible' section, see example below. +2. specify pinctrl states "default" and "idle", "sleep" is optional. +3. specify the gpio irq used for detecting sdio irq in suspend + +If configuration is incomplete, a warning message is emitted "falling back to +polling". Also check the "sdio irq mode" in /sys/kernel/debug/mmc0/regs. Mind +not every application needs SDIO irq, e.g. MMC cards. + + mmc1: mmc@48060100 { + compatible = "ti,am33xx-hsmmc"; + ... + pinctrl-names = "default", "idle", "sleep" + pinctrl-0 = <&mmc1_pins>; + pinctrl-1 = <&mmc1_idle>; + pinctrl-2 = <&mmc1_sleep>; + ... + interrupts-extended = <&intc 64 &gpio2 28 0>; + }; + + mmc1_idle : pinmux_cirq_pin { + pinctrl-single,pins = < + 0x0f8 0x3f /* GPIO2_28 */ + >; + }; diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c index 0febb17..35ac2e4 100644 --- a/drivers/mmc/host/omap_hsmmc.c +++ b/drivers/mmc/host/omap_hsmmc.c @@ -1754,15 +1754,33 @@ static int omap_hsmmc_configure_wake_irq(struct omap_hsmmc_host *host) * and need to remux SDIO DAT1 to GPIO for wake-up from idle. */ if (host->pdata->controller_flags & OMAP_HSMMC_SWAKEUP_MISSING) { - ret = -ENODEV; - devm_free_irq(host->dev, host->wake_irq, host); - goto err; + struct pinctrl *p = devm_pinctrl_get(host->dev); + if (!p) { + ret = -ENODEV; + goto err_free_irq; + } + if (IS_ERR(pinctrl_lookup_state(p, PINCTRL_STATE_DEFAULT))) { + dev_info(host->dev, "missing default pinctrl state\n"); + devm_pinctrl_put(p); + ret = -EINVAL; + goto err_free_irq; + } + + if (IS_ERR(pinctrl_lookup_state(p, PINCTRL_STATE_IDLE))) { + dev_info(host->dev, "missing idle pinctrl state\n"); + devm_pinctrl_put(p); + ret = -EINVAL; + goto err_free_irq; + } + devm_pinctrl_put(p); } OMAP_HSMMC_WRITE(host->base, HCTL, OMAP_HSMMC_READ(host->base, HCTL) | IWE); return 0; +err_free_irq: + devm_free_irq(host->dev, host->wake_irq, host); err: dev_warn(host->dev, "no SDIO IRQ support, falling back to polling\n"); host->wake_irq = 0;