From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arindam Nath Subject: [PATCH v2 03/12] mmc: sd: query function modes for uhs cards Date: Fri, 4 Mar 2011 17:02:40 +0530 Message-ID: <1299238369-1768-4-git-send-email-arindam.nath@amd.com> References: <1299238369-1768-1-git-send-email-arindam.nath@amd.com> Return-path: Received: from mail-iw0-f174.google.com ([209.85.214.174]:35883 "EHLO mail-iw0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759397Ab1CDLdp (ORCPT ); Fri, 4 Mar 2011 06:33:45 -0500 Received: by iwn34 with SMTP id 34so1816372iwn.19 for ; Fri, 04 Mar 2011 03:33:45 -0800 (PST) In-Reply-To: <1299238369-1768-1-git-send-email-arindam.nath@amd.com> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: cjb@laptop.org Cc: zhangfei.gao@gmail.com, prakity@marvell.com, subhashj@codeaurora.org, linux-mmc@vger.kernel.org, henry.su@amd.com, aaron.lu@amd.com, anath.amd@gmail.com, Arindam Nath SD cards which conform to Physical Layer Spec v3.01 can support additional Bus Speed Modes, Driver Strength, and Current Limit other than the default values. We use CMD6 mode 0 to read these additional card functions. The values read here will be used during UHS-I initialization steps. Signed-off-by: Arindam Nath --- drivers/mmc/core/sd.c | 99 +++++++++++++++++++++++++++++++++++++++------- include/linux/mmc/card.h | 3 + 2 files changed, 87 insertions(+), 15 deletions(-) diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index 3e82599..a63956b 100644 --- a/drivers/mmc/core/sd.c +++ b/drivers/mmc/core/sd.c @@ -283,25 +283,94 @@ static int mmc_read_switch(struct mmc_card *card) return -ENOMEM; } - err = mmc_sd_switch(card, 0, 0, 1, status); - if (err) { - /* If the host or the card can't do the switch, - * fail more gracefully. */ - if ((err != -EINVAL) - && (err != -ENOSYS) - && (err != -EFAULT)) + if (card->scr.sda_spec3) { + /* First find out the supported Bus Speed Modes. */ + err = mmc_sd_switch(card, 0, 0, 1, status); + if (err) { + /* + * If the host or the card can't do the switch, + * fail more gracefully. + */ + if ((err != -EINVAL) + && (err != -ENOSYS) + && (err != -EFAULT)) + goto out; + + printk(KERN_WARNING "%s: problem reading " + "Bus Speed modes.\n", + mmc_hostname(card->host)); + err = 0; + goto out; + } - printk(KERN_WARNING "%s: problem reading switch " - "capabilities, performance might suffer.\n", - mmc_hostname(card->host)); - err = 0; + card->sw_caps.uhs_bus_mode = status[13]; + + /* Find out Driver Strengths supported by the card */ + err = mmc_sd_switch(card, 0, 2, 1, status); + if (err) { + /* + * If the host or the card can't do the switch, + * fail more gracefully. + */ + if ((err != -EINVAL) + && (err != -ENOSYS) + && (err != -EFAULT)) + goto out; + + printk(KERN_WARNING "%s: problem reading " + "Driver Strength.\n", + mmc_hostname(card->host)); + err = 0; - goto out; - } + goto out; + } - if (status[13] & 0x02) - card->sw_caps.hs_max_dtr = 50000000; + card->sw_caps.uhs_drv_type = status[9]; + + /* Find out Current Limits supported by the card */ + err = mmc_sd_switch(card, 0, 3, 1, status); + if (err) { + /* + * If the host or the card can't do the switch, + * fail more gracefully. + */ + if ((err != -EINVAL) + && (err != -ENOSYS) + && (err != -EFAULT)) + goto out; + + printk(KERN_WARNING "%s: problem reading " + "Current Limit.\n", + mmc_hostname(card->host)); + err = 0; + + goto out; + } + + card->sw_caps.uhs_curr_limit = status[7]; + } else { + err = mmc_sd_switch(card, 0, 0, 1, status); + if (err) { + /* + * If the host or the card can't do the switch, + * fail more gracefully. + */ + if ((err != -EINVAL) + && (err != -ENOSYS) + && (err != -EFAULT)) + goto out; + + printk(KERN_WARNING "%s: problem reading switch " + "capabilities, performance might suffer.\n", + mmc_hostname(card->host)); + err = 0; + goto out; + } + + if (status[13] & 0x02) + card->sw_caps.hs_max_dtr = 50000000; + } out: kfree(status); diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h index 22b0335..7080f22 100644 --- a/include/linux/mmc/card.h +++ b/include/linux/mmc/card.h @@ -75,6 +75,9 @@ struct sd_ssr { struct sd_switch_caps { unsigned int hs_max_dtr; + unsigned int uhs_bus_mode; + unsigned int uhs_drv_type; + unsigned int uhs_curr_limit; }; struct sdio_cccr { -- 1.7.1