From patchwork Tue Jul 24 16:59:05 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 1232631 Return-Path: X-Original-To: patchwork-linux-mmc@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id E87BDDF25A for ; Tue, 24 Jul 2012 16:59:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755583Ab2GXQ7T (ORCPT ); Tue, 24 Jul 2012 12:59:19 -0400 Received: from mail-we0-f202.google.com ([74.125.82.202]:52100 "EHLO mail-we0-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755520Ab2GXQ7S (ORCPT ); Tue, 24 Jul 2012 12:59:18 -0400 Received: by weyr1 with SMTP id r1so402179wey.1 for ; Tue, 24 Jul 2012 09:59:17 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references :x-gm-message-state; bh=FVCAMji7WUTci0JW9HNsJ6AsYimdvF54bOKC2eJoB9c=; b=TNtzPODszyL9z1uPpxR4jLvclqkYs+U2plGY0AcQxCRpFG7TNInEpHSs3jS/CmCUTx 46QcGZkOarZMdlh+eSbTZrMWi2AZKU/AmalpsEQHpOYjUPBKvvqQMD4pv9fVUzUbDVV4 Blp1CTmYE4zOS4J0M59Pg/6TBgcJodBg336Cgy/UGQtfH9inPoP9XJ+JdW0lzcnuleoI jPV0n7cLVRAouRcQALCPuOCqvQWB4IiLDB1ErDqo1lGKt2q27VjJGXJuDu1SaNXGuuxW QnTtSdCcRbYOEmP9vgxu354KxD1TLXZwp3WoFOSV2Evl/haww8Hg+Gr6BXrksiVvK7w8 /zrw== Received: by 10.180.73.146 with SMTP id l18mr847345wiv.4.1343149157536; Tue, 24 Jul 2012 09:59:17 -0700 (PDT) Received: by 10.180.73.146 with SMTP id l18mr847316wiv.4.1343149157471; Tue, 24 Jul 2012 09:59:17 -0700 (PDT) Received: from hpza10.eem.corp.google.com ([74.125.121.33]) by gmr-mx.google.com with ESMTPS id 46si31900eed.1.2012.07.24.09.59.17 (version=TLSv1/SSLv3 cipher=AES128-SHA); Tue, 24 Jul 2012 09:59:17 -0700 (PDT) Received: from peppermint.mtv.corp.google.com (peppermint.mtv.corp.google.com [172.22.162.25]) by hpza10.eem.corp.google.com (Postfix) with ESMTP id 0F99720004E; Tue, 24 Jul 2012 09:59:17 -0700 (PDT) Received: by peppermint.mtv.corp.google.com (Postfix, from userid 121310) id 5BB2A19AA34; Tue, 24 Jul 2012 09:59:16 -0700 (PDT) From: Doug Anderson To: linux-mmc@vger.kernel.org Cc: Chris Ball , Will Newton , James Hogan , Seungwon Jeon , Jaehoon Chung , linux-kernel@vger.kernel.org, Grant Grundler , Olof Johansson , shashidharh@vayavyalabs.com, ki0351.kim@samsung.com, Doug Anderson Subject: [PATCH v3] mmc: dw_mmc: Disable low power mode if SDIO interrupts are used Date: Tue, 24 Jul 2012 09:59:05 -0700 Message-Id: <1343149145-22927-1-git-send-email-dianders@chromium.org> X-Mailer: git-send-email 1.7.7.3 In-Reply-To: References: X-Gm-Message-State: ALoCoQkIHc8eHVJ+WhPgKsmjIIjdZAE/4uHSz68XUZ5BXyLEsBgahp9YSr/+9J63n2MIUU+niOUlsVLshyC8zwICBi4nh4Gn72HqUcytN81/8iUk67OLvknLLew9lYwi6+5bgSKaxf9wgGJFPE8O6ngtydwOv2vK1gtvQmxNDFFfM3M7B0rpapwZhi8AJMZEv4gVKx5zYVKM Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org The documentation for the dw_mmc part says that the low power mode should normally only be set for MMC and SD memory and should be turned off for SDIO cards that need interrupts detected. The best place I could find to do this is when the SDIO interrupt was first enabled. I rely on the fact that dw_mci_setup_bus() will be called when it's time to reenable. Signed-off-by: Doug Anderson Acked-by: Will Newton Reviewed-by: Jaehoon Chung --- Changes in v3: - Commenting fixes requested by Seungwoon Jeon and Jaehoon Chung. - Only pass 'slot' to the low power disable function since whole mmc structure wasn't needed. Changes in v2: - Commenting fixes requested by Grant Grundler. - Be extra certain that we don't re-turn on the low power mode in CLKENA in dw_mci_setup_bus() if SDIO interrupts are enabled. There are no known instances of this happening but it's good to be safe. drivers/mmc/host/dw_mmc.c | 41 ++++++++++++++++++++++++++++++++++++++--- 1 files changed, 38 insertions(+), 3 deletions(-) diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index 72dc3cd..fbe5be3 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -627,6 +627,7 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot) { struct dw_mci *host = slot->host; u32 div; + u32 clk_en_a; if (slot->clock != host->current_speed) { div = host->bus_hz / slot->clock; @@ -659,9 +660,11 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot) mci_send_cmd(slot, SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0); - /* enable clock */ - mci_writel(host, CLKENA, ((SDMMC_CLKEN_ENABLE | - SDMMC_CLKEN_LOW_PWR) << slot->id)); + /* enable clock; only low power if no SDIO */ + clk_en_a = SDMMC_CLKEN_ENABLE << slot->id; + if (!(mci_readl(host, INTMASK) & SDMMC_INT_SDIO(slot->id))) + clk_en_a |= SDMMC_CLKEN_LOW_PWR << slot->id; + mci_writel(host, CLKENA, clk_en_a); /* inform CIU */ mci_send_cmd(slot, @@ -862,6 +865,30 @@ static int dw_mci_get_cd(struct mmc_host *mmc) return present; } +/* + * Disable lower power mode. + * + * Low power mode will stop the card clock when idle. According to the + * description of the CLKENA register we should disable low power mode + * for SDIO cards if we need SDIO interrupts to work. + * + * This function is fast if low power mode is already disabled. + */ +static void dw_mci_disable_low_power(struct dw_mci_slot *slot) +{ + struct dw_mci *host = slot->host; + u32 clk_en_a; + const u32 clken_low_pwr = SDMMC_CLKEN_LOW_PWR << slot->id; + + clk_en_a = mci_readl(host, CLKENA); + + if (clk_en_a & clken_low_pwr) { + mci_writel(host, CLKENA, clk_en_a & ~clken_low_pwr); + mci_send_cmd(slot, SDMMC_CMD_UPD_CLK | + SDMMC_CMD_PRV_DAT_WAIT, 0); + } +} + static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb) { struct dw_mci_slot *slot = mmc_priv(mmc); @@ -871,6 +898,14 @@ static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb) /* Enable/disable Slot Specific SDIO interrupt */ int_mask = mci_readl(host, INTMASK); if (enb) { + /* + * Turn off low power mode if it was enabled. This is a bit of + * a heavy operation and we disable / enable IRQs a lot, so + * we'll leave low power mode disabled and it will get + * re-enabled again in dw_mci_setup_bus(). + */ + dw_mci_disable_low_power(mmc_priv(mmc)); + mci_writel(host, INTMASK, (int_mask | SDMMC_INT_SDIO(slot->id))); } else {