From patchwork Sun May 11 11:28:58 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andreas Fenkart X-Patchwork-Id: 4150351 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 1DE119F3EE for ; Sun, 11 May 2014 11:30:52 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 384F5202FE for ; Sun, 11 May 2014 11:30:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 520252028D for ; Sun, 11 May 2014 11:30:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758102AbaEKLas (ORCPT ); Sun, 11 May 2014 07:30:48 -0400 Received: from mail-ve0-f181.google.com ([209.85.128.181]:43956 "EHLO mail-ve0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757805AbaEKLar (ORCPT ); Sun, 11 May 2014 07:30:47 -0400 Received: by mail-ve0-f181.google.com with SMTP id pa12so7345286veb.40 for ; Sun, 11 May 2014 04:30:46 -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=bK7IJoYD2SC37heooTdBQPuelNa2oFMLL2OV2tHSMvg=; b=ZxcaJtAhQyk7lqmxzq/Rrgw+bmj9scdjsa53WK3JKPeBjiq4feZ0XINwnldDO8eQGM EdMbOfpuN5dRTeT43kAMn7p+JE2KusIQcFmw4kxXP3V/dQYPieebgcbs9TYyWX03MEsQ YsPPBW/T28szphruzY19uSl5D3d933h2iH3kf79PEEPqjNN7EvCejTYGHT53hzTwhtB+ IlmM4DuzBTuTuxR2t3X0Flttzehd5ZQa3mBjqsDe/07mIuJq9q9JQiwVJvPt3VkvKcRu 5AqijKttbTxGNaO5HfPOOcnpSAS9xQ5a0XJwyL6S5Ef3m2KoHBHKXh4Kvj/QONhyoxD5 eJyA== X-Received: by 10.52.78.231 with SMTP id e7mr15131663vdx.28.1399807846277; Sun, 11 May 2014 04:30:46 -0700 (PDT) Received: from localhost (ip-89-176-190-91.net.upcbroadband.cz. [89.176.190.91]) by mx.google.com with ESMTPSA id ix8sm7196832vdb.18.2014.05.11.04.30.38 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Sun, 11 May 2014 04:30:45 -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 v11 6/6] mmc: omap_hsmmc: Pin remux workaround to support SDIO interrupt on AM335x Date: Sun, 11 May 2014 13:28:58 +0200 Message-Id: <1399807738-32223-7-git-send-email-afenkart@gmail.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1399807738-32223-1-git-send-email-afenkart@gmail.com> References: <1399807738-32223-1-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 Acked-by: Balaji T K Signed-off-by: Andreas Fenkart Signed-off-by: Tony Lindgren 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 3c8b183..d22ac3f 100644 --- a/drivers/mmc/host/omap_hsmmc.c +++ b/drivers/mmc/host/omap_hsmmc.c @@ -1753,15 +1753,25 @@ 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; + if (IS_ERR(host->dev->pins->default_state)) { + dev_info(host->dev, "missing default pinctrl state\n"); + ret = -EINVAL; + goto err_free_irq; + } + + if (IS_ERR(host->dev->pins->idle_state)) { + dev_info(host->dev, "missing idle pinctrl state\n"); + ret = -EINVAL; + goto err_free_irq; + } } 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;