mmc: meson-gx: add support for HS400 mode

Commit Message

Heiner Kallweit Jan. 26, 2017, 10:12 p.m. UTC

Add support for HS400 mode.

Successfully tested on a Odroid C2 (S905 GXBB).

Signed-off-by: Heiner Kallweit <[e-mail]>
---
 drivers/mmc/host/meson-gx-mmc.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

Comments

Kevin Hilman Jan. 27, 2017, 6:55 p.m. UTC | #1

Heiner Kallweit <[e-mail]> writes:

> Add support for HS400 mode.
>
> Successfully tested on a Odroid C2 (S905 GXBB).
>
> Signed-off-by: Heiner Kallweit <[e-mail]>

Excellent!  Thanks for the patch.

Reviewed-by: Kevin Hilman <[e-mail]>
Tested-by: Kevin Hilman <[e-mail]>

Some folks on IRC had reported that eMMC wasn't working on some boards
(like Amlogic P200) and with this patch, it's working again for me on P200.

@Andreas: does this patch fix your R-box Pro?

Kevin

> ---
>  drivers/mmc/host/meson-gx-mmc.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
>
> diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
> index 030425be..be45d57d 100644
> --- a/drivers/mmc/host/meson-gx-mmc.c
> +++ b/drivers/mmc/host/meson-gx-mmc.c
> @@ -83,6 +83,7 @@
>  #define   CFG_RC_CC_MASK 0xf
>  #define   CFG_STOP_CLOCK BIT(22)
>  #define   CFG_CLK_ALWAYS_ON BIT(18)
> +#define   CFG_CHK_DS BIT(20)
>  #define   CFG_AUTO_CLK BIT(23)
>  
>  #define SD_EMMC_STATUS 0x48
> @@ -412,6 +413,16 @@ static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>  	val &= ~(CFG_RC_CC_MASK << CFG_RC_CC_SHIFT);
>  	val |= ilog2(SD_EMMC_CFG_CMD_GAP) << CFG_RC_CC_SHIFT;
>  
> +	val &= ~CFG_DDR;
> +	if (ios->timing == MMC_TIMING_UHS_DDR50 ||
> +	    ios->timing == MMC_TIMING_MMC_DDR52 ||
> +	    ios->timing == MMC_TIMING_MMC_HS400)
> +		val |= CFG_DDR;
> +
> +	val &= ~CFG_CHK_DS;
> +	if (ios->timing == MMC_TIMING_MMC_HS400)
> +		val |= CFG_CHK_DS;
> +
>  	writel(val, host->regs + SD_EMMC_CFG);
>  
>  	if (val != orig)

Neil Armstrong Feb. 6, 2017, 9:32 a.m. UTC | #2

On 01/27/2017 07:55 PM, Kevin Hilman wrote:
> Heiner Kallweit <[e-mail]> writes:
> 
>> Add support for HS400 mode.
>>
>> Successfully tested on a Odroid C2 (S905 GXBB).
>>
>> Signed-off-by: Heiner Kallweit <[e-mail]>
> 
> Excellent!  Thanks for the patch.
> 
> Reviewed-by: Kevin Hilman <[e-mail]>
> Tested-by: Kevin Hilman <[e-mail]>
> 
> Some folks on IRC had reported that eMMC wasn't working on some boards
> (like Amlogic P200) and with this patch, it's working again for me on P200.
> 
> @Andreas: does this patch fix your R-box Pro?
> 
> Kevin

Hi Heiner,

Actually activating HS400 and DDR modes should need DT attributes to actually enable them
in the MMC core code, and it seems the hardware needs some timings adjustment to use these
modes. If you consider they are enabled by U-boot, good but it won't always be the case !

Ulf, what is exactly needed to support these modes ?
In other drivers and Amlogic own driver, they have support for the some calibration
commands handling.

Neil

> 
>> ---
>>  drivers/mmc/host/meson-gx-mmc.c | 11 +++++++++++
>>  1 file changed, 11 insertions(+)
>>
>> diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
>> index 030425be..be45d57d 100644
>> --- a/drivers/mmc/host/meson-gx-mmc.c
>> +++ b/drivers/mmc/host/meson-gx-mmc.c
>> @@ -83,6 +83,7 @@
>>  #define   CFG_RC_CC_MASK 0xf
>>  #define   CFG_STOP_CLOCK BIT(22)
>>  #define   CFG_CLK_ALWAYS_ON BIT(18)
>> +#define   CFG_CHK_DS BIT(20)
>>  #define   CFG_AUTO_CLK BIT(23)
>>  
>>  #define SD_EMMC_STATUS 0x48
>> @@ -412,6 +413,16 @@ static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>>  	val &= ~(CFG_RC_CC_MASK << CFG_RC_CC_SHIFT);
>>  	val |= ilog2(SD_EMMC_CFG_CMD_GAP) << CFG_RC_CC_SHIFT;
>>  
>> +	val &= ~CFG_DDR;
>> +	if (ios->timing == MMC_TIMING_UHS_DDR50 ||
>> +	    ios->timing == MMC_TIMING_MMC_DDR52 ||
>> +	    ios->timing == MMC_TIMING_MMC_HS400)
>> +		val |= CFG_DDR;
>> +
>> +	val &= ~CFG_CHK_DS;
>> +	if (ios->timing == MMC_TIMING_MMC_HS400)
>> +		val |= CFG_CHK_DS;
>> +
>>  	writel(val, host->regs + SD_EMMC_CFG);
>>  
>>  	if (val != orig)

Heiner Kallweit Feb. 6, 2017, 6:28 p.m. UTC | #3

Am 06.02.2017 um 10:32 schrieb Neil Armstrong:
> On 01/27/2017 07:55 PM, Kevin Hilman wrote:
>> Heiner Kallweit <[e-mail]> writes:
>>
>>> Add support for HS400 mode.
>>>
>>> Successfully tested on a Odroid C2 (S905 GXBB).
>>>
>>> Signed-off-by: Heiner Kallweit <[e-mail]>
>>
>> Excellent!  Thanks for the patch.
>>
>> Reviewed-by: Kevin Hilman <[e-mail]>
>> Tested-by: Kevin Hilman <[e-mail]>
>>
>> Some folks on IRC had reported that eMMC wasn't working on some boards
>> (like Amlogic P200) and with this patch, it's working again for me on P200.
>>
>> @Andreas: does this patch fix your R-box Pro?
>>
>> Kevin
> 
> Hi Heiner,
> 
> Actually activating HS400 and DDR modes should need DT attributes to actually enable them
> in the MMC core code, and it seems the hardware needs some timings adjustment to use these
> modes. If you consider they are enabled by U-boot, good but it won't always be the case !
> 
Sure, to enable HS400 the related DT property needs to be set. I did this for my tests.
HS400 worked out of the box with 200MHz and a Hardkernel 8GB eMMC card.
However with a Hardkernel 128GB card I have issues with 200MHz even in SDR mode.
So yes, it seems at least tuning support needs to be added to the driver.

By the way: With the current mainline driver I have terrible performance, reads in
the range 10-15 MB/s. Even the uboot driver is faster, at least it states that it
reads the kernel image with 40 MB/s.

> Ulf, what is exactly needed to support these modes ?
> In other drivers and Amlogic own driver, they have support for the some calibration
> commands handling.
> 
Chip-internal calibration support sounds nice, however I have only the Amlogic driver
as basis and the pure register description in the Hardkernel-provided S905GXBB spec.
The spec misses more detailed information on how the calibration support works and
how the registers are supposed to be used.

> Neil
> 
>>
>>> ---
>>>  drivers/mmc/host/meson-gx-mmc.c | 11 +++++++++++
>>>  1 file changed, 11 insertions(+)
>>>
>>> diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
>>> index 030425be..be45d57d 100644
>>> --- a/drivers/mmc/host/meson-gx-mmc.c
>>> +++ b/drivers/mmc/host/meson-gx-mmc.c
>>> @@ -83,6 +83,7 @@
>>>  #define   CFG_RC_CC_MASK 0xf
>>>  #define   CFG_STOP_CLOCK BIT(22)
>>>  #define   CFG_CLK_ALWAYS_ON BIT(18)
>>> +#define   CFG_CHK_DS BIT(20)
>>>  #define   CFG_AUTO_CLK BIT(23)
>>>  
>>>  #define SD_EMMC_STATUS 0x48
>>> @@ -412,6 +413,16 @@ static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>>>  	val &= ~(CFG_RC_CC_MASK << CFG_RC_CC_SHIFT);
>>>  	val |= ilog2(SD_EMMC_CFG_CMD_GAP) << CFG_RC_CC_SHIFT;
>>>  
>>> +	val &= ~CFG_DDR;
>>> +	if (ios->timing == MMC_TIMING_UHS_DDR50 ||
>>> +	    ios->timing == MMC_TIMING_MMC_DDR52 ||
>>> +	    ios->timing == MMC_TIMING_MMC_HS400)
>>> +		val |= CFG_DDR;
>>> +
>>> +	val &= ~CFG_CHK_DS;
>>> +	if (ios->timing == MMC_TIMING_MMC_HS400)
>>> +		val |= CFG_CHK_DS;
>>> +
>>>  	writel(val, host->regs + SD_EMMC_CFG);
>>>  
>>>  	if (val != orig)
> 
>

Patch

diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index 030425be..be45d57d 100644
--- a/drivers/mmc/host/meson-gx-mmc.c
+++ b/drivers/mmc/host/meson-gx-mmc.c
@@ -83,6 +83,7 @@ 
 #define   CFG_RC_CC_MASK 0xf
 #define   CFG_STOP_CLOCK BIT(22)
 #define   CFG_CLK_ALWAYS_ON BIT(18)
+#define   CFG_CHK_DS BIT(20)
 #define   CFG_AUTO_CLK BIT(23)
 
 #define SD_EMMC_STATUS 0x48
@@ -412,6 +413,16 @@  static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 	val &= ~(CFG_RC_CC_MASK << CFG_RC_CC_SHIFT);
 	val |= ilog2(SD_EMMC_CFG_CMD_GAP) << CFG_RC_CC_SHIFT;
 
+	val &= ~CFG_DDR;
+	if (ios->timing == MMC_TIMING_UHS_DDR50 ||
+	    ios->timing == MMC_TIMING_MMC_DDR52 ||
+	    ios->timing == MMC_TIMING_MMC_HS400)
+		val |= CFG_DDR;
+
+	val &= ~CFG_CHK_DS;
+	if (ios->timing == MMC_TIMING_MMC_HS400)
+		val |= CFG_CHK_DS;
+
 	writel(val, host->regs + SD_EMMC_CFG);
 
 	if (val != orig)