Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753481AbZG3Ltv (ORCPT ); Thu, 30 Jul 2009 07:49:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753332AbZG3Ltu (ORCPT ); Thu, 30 Jul 2009 07:49:50 -0400 Received: from mail-ew0-f214.google.com ([209.85.219.214]:38088 "EHLO mail-ew0-f214.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753242AbZG3Ltt (ORCPT ); Thu, 30 Jul 2009 07:49:49 -0400 Subject: [PATCH] sdio: add CD disable support From: Ohad Ben-Cohen To: Andrew Morton Cc: Philip Langdale , Matt Fleming , ian@mnementh.co.uk, pierre@ossman.eu, linux-kernel@vger.kernel.org, linux-embedded@vger.kernel.org, nico@cam.org, nicolas.ferre@rfo.atmel.com, hskinnemoen@atmel.com, tony@atomide.com, david-b@pacbell.net, manuel.lauss@gmail.com, mirq-l@jasper.es, Adrian Hunter , Madhusudhan Content-Type: text/plain Date: Thu, 30 Jul 2009 14:54:08 +0300 Message-Id: <1248954848.5396.6.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.22.3.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2222 Lines: 87 From: Ohad Ben-Cohen To save power, the pull-up resistor on CD/DAT[3] (pin 1) of the card can be disconnected. This is desired, e.g., with embedded SDIO devices which do not rely on this pin for card detection. Signed-off-by: Ohad Ben-Cohen --- drivers/mmc/core/sdio.c | 32 ++++++++++++++++++++++++++++++++ include/linux/mmc/card.h | 3 ++- 2 files changed, 34 insertions(+), 1 deletions(-) diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c index fb99ccf..4c4c9a9 100644 --- a/drivers/mmc/core/sdio.c +++ b/drivers/mmc/core/sdio.c @@ -165,6 +165,31 @@ static int sdio_enable_wide(struct mmc_card *card) } /* + * Disconnect the pull-up resistor on CD/DAT[3] if requested by the card. + * If card detection is not needed, this can save some power. + */ +static int sdio_disable_cd(struct mmc_card *card) +{ + int ret; + u8 ctrl; + + if (!card->cccr.disable_cd) + return 0; + + ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_IF, 0, &ctrl); + if (ret) + return ret; + + ctrl |= SDIO_BUS_CD_DISABLE; + + ret = mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_IF, ctrl, NULL); + if (ret) + return ret; + + return 0; +} + +/* * Test if the card supports high-speed mode and, if so, switch to it. */ static int sdio_enable_hs(struct mmc_card *card) @@ -392,6 +417,13 @@ int mmc_attach_sdio(struct mmc_host *host, u32 ocr) goto remove; /* + * Disconnect card detection pull-up resistor (if requested by card). + */ + err = sdio_disable_cd(card); + if (err) + goto remove; + + /* * Initialize (but don't add) all present functions. */ for (i = 0;i < funcs;i++) { diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h index 403aa50..82a8488 100644 --- a/include/linux/mmc/card.h +++ b/include/linux/mmc/card.h @@ -62,7 +62,8 @@ struct sdio_cccr { low_speed:1, wide_bus:1, high_power:1, - high_speed:1; + high_speed:1, + disable_cd:1; }; struct sdio_cis { -- 1.5.4.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/