From patchwork Wed Apr 20 09:30:56 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arindam Nath X-Patchwork-Id: 721351 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id p3K9WGP2031314 for ; Wed, 20 Apr 2011 09:32:42 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753741Ab1DTJcl (ORCPT ); Wed, 20 Apr 2011 05:32:41 -0400 Received: from mail-px0-f179.google.com ([209.85.212.179]:46142 "EHLO mail-px0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753702Ab1DTJcl (ORCPT ); Wed, 20 Apr 2011 05:32:41 -0400 Received: by mail-px0-f179.google.com with SMTP id 2so445901pxi.10 for ; Wed, 20 Apr 2011 02:32:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:sender:from:to:cc:subject:date:message-id :x-mailer:in-reply-to:references; bh=T3WsjvpNwhN//h6GgklS6MJEBmQWyBNuICQLL7MudsM=; b=D+aa3rnsjBASvs8EwnFqpGobRKgZplpAqyfmno7/78plEch0gt6/hD0Qi3kAoIoM3E U6oEns9lJ7jhm3ubrmAWpFbHf7+EWyBJk3PnAL14b3EANFZfi43Lhc6KeIC3YkARxaGm CP59BO9UTXqrd612rHfy2btcPOM2QvwW073rk= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:from:to:cc:subject:date:message-id:x-mailer:in-reply-to :references; b=iyFm5m0qtqU9JnvRA8YVE/bqtJf84nkOIr+QN+g/AxiELwTiBEOtLNZx4CI9/OV/Xr yczY1PXfGfGO4oAuJ0XkJ4tey6uV59+fSuTEyaIE6Xd9nnj1TGxlooBGVjT/B+DTkmgB mkD2tkzZ1oSNrshVAHJlfFRCQPnvmclSbJhz0= Received: by 10.68.63.161 with SMTP id h1mr10425949pbs.354.1303291961214; Wed, 20 Apr 2011 02:32:41 -0700 (PDT) Received: from localhost ([122.167.17.41]) by mx.google.com with ESMTPS id a4sm526417pbs.25.2011.04.20.02.32.34 (version=TLSv1/SSLv3 cipher=OTHER); Wed, 20 Apr 2011 02:32:40 -0700 (PDT) From: Arindam Nath To: cjb@laptop.org Cc: linux-mmc@vger.kernel.org, prakity@marvell.com, subhashj@codeaurora.org, zhangfei.gao@gmail.com, henry.su@amd.com, aaron.lu@amd.com, anath.amd@gmail.com, Arindam Nath Subject: [PATCH v3 06/11] mmc: sd: set current limit for uhs cards Date: Wed, 20 Apr 2011 15:00:56 +0530 Message-Id: <1303291861-1788-7-git-send-email-arindam.nath@amd.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1303291861-1788-1-git-send-email-arindam.nath@amd.com> References: <1303291861-1788-1-git-send-email-arindam.nath@amd.com> Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Wed, 20 Apr 2011 09:32:42 +0000 (UTC) We decide on the current limit to be set for the card based on the Capability of Host Controller to provide current at 1.8V signalling, and the maximum current limit of the card as indicated by CMD6 mode 0. We then set the current limit for the card using CMD6 mode 1. As per the Physical Layer Spec v3.01, the current limit switch is only applicable for SDR50, SDR104, and DDR50 bus speed modes. For other UHS-I modes, we set the default current limit of 200mA. Signed-off-by: Arindam Nath --- drivers/mmc/core/sd.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++ drivers/mmc/host/sdhci.c | 10 +++++++ include/linux/mmc/card.h | 9 ++++++ include/linux/mmc/host.h | 4 +++ 4 files changed, 86 insertions(+), 0 deletions(-) diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index ba71654..9af0c94 100644 --- a/drivers/mmc/core/sd.c +++ b/drivers/mmc/core/sd.c @@ -517,6 +517,64 @@ static int sd_set_bus_speed_mode(struct mmc_card *card, u8 *status) return 0; } +static int sd_set_current_limit(struct mmc_card *card, u8 *status) +{ + int current_limit = 0; + int err; + + /* + * Current limit switch is only defined for SDR50, SDR104, and DDR50 + * bus speed modes. For other bus speed modes, we set the default + * current limit of 200mA. + */ + if ((card->sd_bus_speed == UHS_SDR50_BUS_SPEED) || + (card->sd_bus_speed == UHS_SDR104_BUS_SPEED) || + (card->sd_bus_speed == UHS_DDR50_BUS_SPEED)) { + if (card->host->caps & MMC_CAP_MAX_CURRENT_800) { + if (card->sw_caps.sd3_curr_limit & SD_MAX_CURRENT_800) + current_limit = SD_SET_CURRENT_LIMIT_800; + else if (card->sw_caps.sd3_curr_limit & + SD_MAX_CURRENT_600) + current_limit = SD_SET_CURRENT_LIMIT_600; + else if (card->sw_caps.sd3_curr_limit & + SD_MAX_CURRENT_400) + current_limit = SD_SET_CURRENT_LIMIT_400; + else if (card->sw_caps.sd3_curr_limit & + SD_MAX_CURRENT_200) + current_limit = SD_SET_CURRENT_LIMIT_200; + } else if (card->host->caps & MMC_CAP_MAX_CURRENT_600) { + if (card->sw_caps.sd3_curr_limit & SD_MAX_CURRENT_600) + current_limit = SD_SET_CURRENT_LIMIT_600; + else if (card->sw_caps.sd3_curr_limit & + SD_MAX_CURRENT_400) + current_limit = SD_SET_CURRENT_LIMIT_400; + else if (card->sw_caps.sd3_curr_limit & + SD_MAX_CURRENT_200) + current_limit = SD_SET_CURRENT_LIMIT_200; + } else if (card->host->caps & MMC_CAP_MAX_CURRENT_400) { + if (card->sw_caps.sd3_curr_limit & SD_MAX_CURRENT_400) + current_limit = SD_SET_CURRENT_LIMIT_400; + else if (card->sw_caps.sd3_curr_limit & + SD_MAX_CURRENT_200) + current_limit = SD_SET_CURRENT_LIMIT_200; + } else if (card->host->caps & MMC_CAP_MAX_CURRENT_200) { + if (card->sw_caps.sd3_curr_limit & SD_MAX_CURRENT_200) + current_limit = SD_SET_CURRENT_LIMIT_200; + } + } else + current_limit = SD_SET_CURRENT_LIMIT_200; + + err = mmc_sd_switch(card, 1, 3, current_limit, status); + if (err) + return err; + + if (((status[15] >> 4) & 0x0F) != current_limit) + printk(KERN_WARNING "%s: Problem setting current limit!\n", + mmc_hostname(card->host)); + + return 0; +} + /* * UHS-I specific initialization procedure */ @@ -555,6 +613,11 @@ static int mmc_sd_init_uhs_card(struct mmc_card *card) /* Set bus speed mode of the card */ err = sd_set_bus_speed_mode(card, status); + if (err) + goto out; + + /* Set current limit for the card */ + err = sd_set_current_limit(card, status); out: kfree(status); diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 758c9f1..9141c5b 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -2185,6 +2185,16 @@ int sdhci_add_host(struct sdhci_host *host) if (max_current_180 > 150) mmc->caps |= MMC_CAP_SET_XPC_180; + + /* Maximum current capabilities of the host at 1.8V */ + if (max_current_180 >= 800) + mmc->caps |= MMC_CAP_MAX_CURRENT_800; + else if (max_current_180 >= 600) + mmc->caps |= MMC_CAP_MAX_CURRENT_600; + else if (max_current_180 >= 400) + mmc->caps |= MMC_CAP_MAX_CURRENT_400; + else + mmc->caps |= MMC_CAP_MAX_CURRENT_200; } mmc->ocr_avail = ocr_avail; diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h index 4ef6ded..47b5ad3 100644 --- a/include/linux/mmc/card.h +++ b/include/linux/mmc/card.h @@ -105,6 +105,15 @@ struct sd_switch_caps { #define SD_DRIVER_TYPE_C 0x04 #define SD_DRIVER_TYPE_D 0x08 unsigned int sd3_curr_limit; +#define SD_SET_CURRENT_LIMIT_200 0 +#define SD_SET_CURRENT_LIMIT_400 1 +#define SD_SET_CURRENT_LIMIT_600 2 +#define SD_SET_CURRENT_LIMIT_800 3 + +#define SD_MAX_CURRENT_200 (1 << SD_SET_CURRENT_LIMIT_200) +#define SD_MAX_CURRENT_400 (1 << SD_SET_CURRENT_LIMIT_400) +#define SD_MAX_CURRENT_600 (1 << SD_SET_CURRENT_LIMIT_600) +#define SD_MAX_CURRENT_800 (1 << SD_SET_CURRENT_LIMIT_800) }; struct sdio_cccr { diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 6237599..52b5dc9 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -203,6 +203,10 @@ struct mmc_host { #define MMC_CAP_DRIVER_TYPE_A (1 << 23) /* Host supports Driver Type A */ #define MMC_CAP_DRIVER_TYPE_C (1 << 24) /* Host supports Driver Type C */ #define MMC_CAP_DRIVER_TYPE_D (1 << 25) /* Host supports Driver Type D */ +#define MMC_CAP_MAX_CURRENT_200 (1 << 26) /* Host max current limit is 200mA */ +#define MMC_CAP_MAX_CURRENT_400 (1 << 27) /* Host max current limit is 400mA */ +#define MMC_CAP_MAX_CURRENT_600 (1 << 28) /* Host max current limit is 600mA */ +#define MMC_CAP_MAX_CURRENT_800 (1 << 29) /* Host max current limit is 800mA */ mmc_pm_flag_t pm_caps; /* supported pm features */