From: Arindam Nath <arindam.nath@amd.com>
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 <arindam.nath@amd.com>
Subject: [PATCH v3 06/11] mmc: sd: set current limit for uhs cards
Date: Wed, 20 Apr 2011 15:00:56 +0530 [thread overview]
Message-ID: <1303291861-1788-7-git-send-email-arindam.nath@amd.com> (raw)
In-Reply-To: <1303291861-1788-1-git-send-email-arindam.nath@amd.com>
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 <arindam.nath@amd.com>
---
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 */
--
1.7.1
next prev parent reply other threads:[~2011-04-20 9:32 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-20 9:30 [PATCH v3 00/11] add support for host controller v3.00 Arindam Nath
2011-04-20 9:30 ` [PATCH v3 01/11] mmc: sd: add support for signal voltage switch procedure Arindam Nath
2011-04-27 9:48 ` zhangfei gao
2011-04-27 10:17 ` Nath, Arindam
2011-04-28 3:17 ` zhangfei gao
2011-04-28 5:48 ` Nath, Arindam
2011-04-20 9:30 ` [PATCH v3 02/11] mmc: sd: query function modes for uhs cards Arindam Nath
2011-04-20 9:30 ` [PATCH v3 03/11] mmc: sd: add support for driver type selection Arindam Nath
2011-04-20 9:30 ` [PATCH v3 04/11] mmc: sdhci: reset sdclk before setting high speed enable Arindam Nath
2011-04-20 9:30 ` [PATCH v3 05/11] mmc: sd: add support for uhs bus speed mode selection Arindam Nath
2011-04-20 9:30 ` Arindam Nath [this message]
2011-04-20 9:30 ` [PATCH v3 07/11] mmc: sd: report correct speed and capacity of uhs cards Arindam Nath
2011-04-20 9:30 ` [PATCH v3 08/11] mmc: sd: add support for tuning during uhs initialization Arindam Nath
2011-04-27 18:44 ` Philip Rakity
2011-04-28 6:02 ` Nath, Arindam
2011-04-28 8:29 ` Question about timer in struct sdhci_host Ryan Liu
2011-04-20 9:30 ` [PATCH v3 09/11] mmc: sdhci: enable preset value after uhs initialization Arindam Nath
2011-04-28 5:16 ` zhangfei gao
2011-04-28 5:50 ` Nath, Arindam
2011-04-20 9:31 ` [PATCH v3 10/11] mmc: sdhci: add support for programmable clock mode Arindam Nath
2011-04-20 9:31 ` [PATCH v3 11/11] mmc: sdhci: add support for retuning mode 1 Arindam Nath
2011-04-29 18:40 ` [PATCH v3 00/11] add support for host controller v3.00 Subhash Jadavani
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