From patchwork Fri May 23 08:30:34 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andreas Fenkart X-Patchwork-Id: 4229011 Return-Path: X-Original-To: patchwork-linux-mmc@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 2A77CBF90B for ; Fri, 23 May 2014 08:32:08 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 43675202DD for ; Fri, 23 May 2014 08:32:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4CCD820383 for ; Fri, 23 May 2014 08:32:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752197AbaEWIcA (ORCPT ); Fri, 23 May 2014 04:32:00 -0400 Received: from mail-ee0-f53.google.com ([74.125.83.53]:40510 "EHLO mail-ee0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751573AbaEWIb6 (ORCPT ); Fri, 23 May 2014 04:31:58 -0400 Received: by mail-ee0-f53.google.com with SMTP id c13so3342156eek.40 for ; Fri, 23 May 2014 01:31:56 -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=cFPi5oiUAxDte/a15NwaOqOjXmmBBotkveNth4Djtpc=; b=YHp1HnunExaNTDCdwQ8ok3wmDhISbW3Bef5v8b9oIFbh13SEaq8S76NUUUmhlopFbo cEeq5o4bZ6rZ5BsCoU3H84QbWUTkurlwNnuTigAsqDuJhxopn7qUywX2gRj0ZdE7d2CN qAi+ficTxb9bbHvrM4ONb4O8azP7thU99jTQh/DqaZfku2OPMCIioEJkpYeHkHYFNtdl a7zrDXBNcG0YpkWtrY9yM01j0f0DXxVcZEhcM4GApUNNJhQkEqeco1VJXyJUUV0RRetP fixLYmTALQoOUgSkQKKBr61L7TmjsgWBVJ/hRcHeFlMa0io3Q+2Fp+ksvBv+Iz++kflc qp4g== X-Received: by 10.15.26.135 with SMTP id n7mr2054583eeu.71.1400833916522; Fri, 23 May 2014 01:31:56 -0700 (PDT) Received: from localhost (ip-89-176-190-91.net.upcbroadband.cz. [89.176.190.91]) by mx.google.com with ESMTPSA id m44sm6603279eep.6.2014.05.23.01.31.54 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Fri, 23 May 2014 01:31:55 -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 v13 7/7] mmc: omap_hsmmc: Pin remux workaround to support SDIO interrupt on AM335x Date: Fri, 23 May 2014 10:30:34 +0200 Message-Id: <1400833834-15893-8-git-send-email-afenkart@gmail.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1400833834-15893-1-git-send-email-afenkart@gmail.com> References: <1400833834-15893-1-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 760b0ac..1238506 100644 --- a/drivers/mmc/host/omap_hsmmc.c +++ b/drivers/mmc/host/omap_hsmmc.c @@ -1752,15 +1752,25 @@ 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;