Hello Shen
On 6/18/2013 4:32 AM, Shen, Jackey wrote:
On Wed, Jun 12, 2013 at 2:16 PM, Giuseppe CAVALLARO <peppe.cavallaro@xxxxxx> wrote:
Although the HC supports HS200 (eMMC) the caps2 are always zero; this means that
no way to use the super speed mode (when init the card).
If the HC support SDR104, for SD3.0, so it also supports HS200 for eMMC and
this patch just sets the MMC_CAP2_HS200 in the host caps2 field.
Capabilities register defined in "SD Host Controller Standard Specification Version 3.00"
doesn't indicate it support HS200(eMMC). Which specification do you refer to?
indeed looking at the arasan spec SD3.0eMMC4.5 it is not clear this
point. Looking at the "SD tuning Block" HS200 modes is mentioned
but indeed no 'explicit' bit in the Host Capability register.
v2: Since SDR104 and HS200 are effectively the same thing the patch deletes
the defines for HS200 and use SDR104.
Why do you think they are the same thing?
SDR104: 1.8V signaling, Frequency up to 208 MHz, up to 104MB/sec
HS200: 1.8/1.2V IO voltage, Frequency 0-200MHz, up to 200MB/sec, bus width 4-bit/8-bit
The patch fixes the caps2 where there was a dead check on a
flags always sets to 0.
Hmm, the point is how to use HS200. We performed some tests
and, maybe, Youssef on copy can give you more details on this.
From the HC cap register bit 33, I think we can understand if SDR104
and HS200 are supported and then frq and bus width are then verified
by commands and configuration.
BR
Peppe
Reported-by: Youssef Triki <youssef.triki@xxxxxx>
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@xxxxxx>
Cc: Philip Rakity <prakity@xxxxxxxxxx>
---
drivers/mmc/host/sdhci.c | 14 +++++++++-----
include/linux/mmc/sdhci.h | 2 +-
2 files changed, 10 insertions(+), 6 deletions(-)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 2ea429c..b8bb3b3 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1846,7 +1846,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
*/
if (((ctrl & SDHCI_CTRL_UHS_MASK) == SDHCI_CTRL_UHS_SDR50) &&
(host->flags & SDHCI_SDR50_NEEDS_TUNING ||
- host->flags & SDHCI_HS200_NEEDS_TUNING))
+ host->flags & SDHCI_SDR104_NEEDS_TUNING))
requires_tuning_nonuhs = true;
if (((ctrl & SDHCI_CTRL_UHS_MASK) == SDHCI_CTRL_UHS_SDR104) ||
@@ -2962,9 +2962,13 @@ int sdhci_add_host(struct sdhci_host *host)
mmc->caps |= MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25;
/* SDR104 supports also implies SDR50 support */
- if (caps[1] & SDHCI_SUPPORT_SDR104)
+ if (caps[1] & SDHCI_SUPPORT_SDR104) {
mmc->caps |= MMC_CAP_UHS_SDR104 | MMC_CAP_UHS_SDR50;
- else if (caps[1] & SDHCI_SUPPORT_SDR50)
+ /* SD3.0: SDR104 is supported so (for eMMC) the caps2
+ * field can be promoted to support HS200.
+ */
+ mmc->caps2 |= MMC_CAP2_HS200;
+ } else if (caps[1] & SDHCI_SUPPORT_SDR50)
mmc->caps |= MMC_CAP_UHS_SDR50;
if (caps[1] & SDHCI_SUPPORT_DDR50)
@@ -2974,9 +2978,9 @@ int sdhci_add_host(struct sdhci_host *host)
if (caps[1] & SDHCI_USE_SDR50_TUNING)
host->flags |= SDHCI_SDR50_NEEDS_TUNING;
- /* Does the host need tuning for HS200? */
+ /* Does the host need tuning for SDR104 / HS200? */
if (mmc->caps2 & MMC_CAP2_HS200)
- host->flags |= SDHCI_HS200_NEEDS_TUNING;
+ host->flags |= SDHCI_SDR104_NEEDS_TUNING;
/* Driver Type(s) (A, C, D) supported by the host */
if (caps[1] & SDHCI_DRIVER_TYPE_A)
diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h
index b838ffc..0b1d7f4 100644
--- a/include/linux/mmc/sdhci.h
+++ b/include/linux/mmc/sdhci.h
@@ -126,7 +126,7 @@ struct sdhci_host {
#define SDHCI_AUTO_CMD23 (1<<7) /* Auto CMD23 support */
#define SDHCI_PV_ENABLED (1<<8) /* Preset value enabled */
#define SDHCI_SDIO_IRQ_ENABLED (1<<9) /* SDIO irq enabled */
-#define SDHCI_HS200_NEEDS_TUNING (1<<10) /* HS200 needs tuning */
+#define SDHCI_SDR104_NEEDS_TUNING (1<<10) /* SDR104/HS200 needs tuning */
#define SDHCI_USING_RETUNING_TIMER (1<<11) /* Host is using a retuning timer for the card */
unsigned int version; /* SDHCI spec. version */
--
1.7.4.4
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