From patchwork Thu May 5 06:49:02 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arindam Nath X-Patchwork-Id: 756022 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 p456pT1C023109 for ; Thu, 5 May 2011 06:51:29 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751358Ab1EEGv3 (ORCPT ); Thu, 5 May 2011 02:51:29 -0400 Received: from mail-pv0-f174.google.com ([74.125.83.174]:61797 "EHLO mail-pv0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751002Ab1EEGv2 (ORCPT ); Thu, 5 May 2011 02:51:28 -0400 Received: by pvg12 with SMTP id 12so837177pvg.19 for ; Wed, 04 May 2011 23:51:28 -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=wI3iNhXhS3Qdls30+gIIb9pCr8Fzc9XNhebx4HBYtsI=; b=lrTbUfrWKbUDBdHEVG9WzCC6FhEqkis62No78GlOH3bUjhxBOjj7YXObt59Ruzvr45 HYi22i8sQ+OqnHpjeY3MnFIaQTX2nRAuM8IHVL6Z3xw9uu3B+npuWBTRn99Vx3YzQfUK UsZpW39VEvHTL6Nzvoh3A0W16+sxwUTJXHCZ0= 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=tkPtnMzmMSYApyl0CfGk7a8TJuhYwzAk6AGozkppTXL4yb97aQRY0S2ihXn6Qa3WXm B2Los2+F+XyvKQ50D7XVVV4mcvN5+hPznPzCFwFtoUKKIm9PG1HjM69wY0CMWHTtzJEa 9y84qAAvPcNJ9SNtvBrU1FBqdFQj+OCONUfgI= Received: by 10.68.40.98 with SMTP id w2mr2752092pbk.144.1304578288175; Wed, 04 May 2011 23:51:28 -0700 (PDT) Received: from localhost ([122.166.82.113]) by mx.google.com with ESMTPS id m4sm1238637pbb.78.2011.05.04.23.51.19 (version=TLSv1/SSLv3 cipher=OTHER); Wed, 04 May 2011 23:51:27 -0700 (PDT) From: Arindam Nath To: cjb@laptop.org Cc: prakity@marvell.com, zhangfei.gao@gmail.com, subhashj@codeaurora.org, linux-mmc@vger.kernel.org, henry.su@amd.com, aaron.lu@amd.com, anath.amd@gmail.com, Arindam Nath Subject: [PATCH v4 06/15] mmc: sd: set current limit for uhs cards Date: Thu, 5 May 2011 12:19:02 +0530 Message-Id: <1304578151-1775-7-git-send-email-arindam.nath@amd.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1304578151-1775-1-git-send-email-arindam.nath@amd.com> References: <1304578151-1775-1-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]); Thu, 05 May 2011 06:51:29 +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 Reviewed-by: Philip Rakity Tested-by: Philip Rakity --- 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 0491978..9270d82 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 de7e6e9..9176911 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -2217,6 +2217,16 @@ 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 */