[PATCH] mmc : export hw reset function info to user

[PATCH] mmc : export hw reset function info to user

[Namjae Jeon]

user app should know whether hw reset function is enable to use it.
so I try to add sysfs file of hw reset function like enhanced area.

Signed-off-by: Namjae Jeon <linkinjeon@gmail.com>
---
 drivers/mmc/core/mmc.c   |    6 ++++++
 include/linux/mmc/card.h |    1 +
 include/linux/mmc/mmc.h  |    1 +
 3 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 10f5a19..06c3ffc 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -355,6 +355,10 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
 	card->ext_csd.raw_trim_mult =
 		ext_csd[EXT_CSD_TRIM_MULT];
 	if (card->ext_csd.rev >= 4) {
+		/* HW reset function feature support.
+		/* user can know it is enable through sysfs interface.
+		card->ext_csd.raw_hw_reset_function =
+			ext_csd[EXT_CSD_RST_FUNCTION];
 		/*
 		 * Enhanced area feature support -- check whether the eMMC
 		 * card has the Enhanced area enabled.  If so, export enhanced
@@ -499,6 +503,7 @@ MMC_DEV_ATTR(serial, "0x%08x\n", card->cid.serial);
 MMC_DEV_ATTR(enhanced_area_offset, "%llu\n",
 		card->ext_csd.enhanced_area_offset);
 MMC_DEV_ATTR(enhanced_area_size, "%u\n", card->ext_csd.enhanced_area_size);
+MMC_DEV_ATTR(raw_hw_reset_function, "0x%02x\n", card->ext_csd.raw_hw_reset_function);
 
 static struct attribute *mmc_std_attrs[] = {
 	&dev_attr_cid.attr,
@@ -514,6 +519,7 @@ static struct attribute *mmc_std_attrs[] = {
 	&dev_attr_serial.attr,
 	&dev_attr_enhanced_area_offset.attr,
 	&dev_attr_enhanced_area_size.attr,
+	&dev_attr_raw_hw_reset_function.attr,
 	NULL,
 };
 
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index b460fc2..237bceb 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -65,6 +65,7 @@ struct mmc_ext_csd {
 	unsigned int		enhanced_area_size;	/* Units: KB */
 	unsigned int		boot_size;		/* in bytes */
 	u8			raw_partition_support;	/* 160 */
+	u8                      raw_hw_reset_function;  /* 162 */
 	u8			raw_erased_mem_count;	/* 181 */
 	u8			raw_ext_csd_structure;	/* 194 */
 	u8			raw_card_type;		/* 196 */
diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index 5a794cb..233c932 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -272,6 +272,7 @@ struct _mmc_csd {
 
 #define EXT_CSD_PARTITION_ATTRIBUTE	156	/* R/W */
 #define EXT_CSD_PARTITION_SUPPORT	160	/* RO */
+#define EXT_CSD_RST_FUNCTION           162     /* R/W */
 #define EXT_CSD_WR_REL_PARAM		166	/* RO */
 #define EXT_CSD_ERASE_GROUP_DEF		175	/* R/W */
 #define EXT_CSD_PART_CONFIG		179	/* R/W */
-- 
1.7.4.4

Re: [PATCH] mmc : export hw reset function info to user

[Andrei Warkentin]

Hi Namjae, others,

----- Original Message -----
> From: "Namjae Jeon" <linkinjeon@gmail.com>
> To: cjb@laptop.org, linux-mmc@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org, "Namjae Jeon" <linkinjeon@gmail.com>
> Sent: Sunday, September 18, 2011 11:20:25 AM
> Subject: [PATCH] mmc : export hw reset function info to user
> 
> user app should know whether hw reset function is enable to use it.
> so I try to add sysfs file of hw reset function like enhanced area.
> 

If we're going to be adding a bunch of attributes from ext_csd, why not
just allow dumping the entire ext_csd in a semi-readable form? Via something like 
hex_dump_to_buffer. This will allow easy human an machine parsing, and be more 
lightweight then adding a sysfs attr for each EXT_CSD byte (of which there are a lot).

I'm basing this on the thought that the only clients of these attrbutes would
either be developers or engineers involved with MMC media, or very specialized
software.

Thoughts?

A

Re: [PATCH] mmc : export hw reset function info to user

[NamJae Jeon]

2011/9/20 Andrei Warkentin <awarkentin@vmware.com>:
> Hi Namjae, others,
>
> ----- Original Message -----
>> From: "Namjae Jeon" <linkinjeon@gmail.com>
>> To: cjb@laptop.org, linux-mmc@vger.kernel.org
>> Cc: linux-kernel@vger.kernel.org, "Namjae Jeon" <linkinjeon@gmail.com>
>> Sent: Sunday, September 18, 2011 11:20:25 AM
>> Subject: [PATCH] mmc : export hw reset function info to user
>>
>> user app should know whether hw reset function is enable to use it.
>> so I try to add sysfs file of hw reset function like enhanced area.
>>
>
> If we're going to be adding a bunch of attributes from ext_csd, why not
> just allow dumping the entire ext_csd in a semi-readable form? Via something like
> hex_dump_to_buffer. This will allow easy human an machine parsing, and be more
> lightweight then adding a sysfs attr for each EXT_CSD byte (of which there are a lot).
>
> I'm basing this on the thought that the only clients of these attrbutes would
> either be developers or engineers involved with MMC media, or very specialized
> software.
>
> Thoughts?
>
> A
>

Hi. Andrei.

We can see all dump of ext_csd by using debugfs like this.

mount -t debugfs /dev/mmcblk0 /mnt/
cat /mnt/mmc0/mmc0\:0001/ext_csd

If user take care of it by showing all dump of ext_csd, we may be
comfortable more without having to worry.
But most of them that they do not know a lot of information.
If we provide some information they need them user friendly, I think
that user can use more easily mmc.

Thanks.

Re: [PATCH] mmc : export hw reset function info to user

[Adrian Hunter]

On 18/09/11 18:20, Namjae Jeon wrote:
> user app should know whether hw reset function is enable to use it.
> so I try to add sysfs file of hw reset function like enhanced area.

This conflicts with my patches:

http://marc.info/?l=linux-mmc&m=131462534514277&w=2
http://marc.info/?l=linux-mmc&m=131462534614281&w=2
http://marc.info/?l=linux-mmc&m=131462534714284&w=2
http://marc.info/?l=linux-mmc&m=131462534814287&w=2
http://marc.info/?l=linux-mmc&m=131462535014290&w=2
http://marc.info/?l=linux-mmc&m=131462535214297&w=2

>
> Signed-off-by: Namjae Jeon<linkinjeon@gmail.com>
> ---
>   drivers/mmc/core/mmc.c   |    6 ++++++
>   include/linux/mmc/card.h |    1 +
>   include/linux/mmc/mmc.h  |    1 +
>   3 files changed, 8 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> index 10f5a19..06c3ffc 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -355,6 +355,10 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
>   	card->ext_csd.raw_trim_mult =
>   		ext_csd[EXT_CSD_TRIM_MULT];
>   	if (card->ext_csd.rev>= 4) {
> +		/* HW reset function feature support.
> +		/* user can know it is enable through sysfs interface.
> +		card->ext_csd.raw_hw_reset_function =
> +			ext_csd[EXT_CSD_RST_FUNCTION];
>   		/*
>   		 * Enhanced area feature support -- check whether the eMMC
>   		 * card has the Enhanced area enabled.  If so, export enhanced
> @@ -499,6 +503,7 @@ MMC_DEV_ATTR(serial, "0x%08x\n", card->cid.serial);
>   MMC_DEV_ATTR(enhanced_area_offset, "%llu\n",
>   		card->ext_csd.enhanced_area_offset);
>   MMC_DEV_ATTR(enhanced_area_size, "%u\n", card->ext_csd.enhanced_area_size);
> +MMC_DEV_ATTR(raw_hw_reset_function, "0x%02x\n", card->ext_csd.raw_hw_reset_function);
>
>   static struct attribute *mmc_std_attrs[] = {
>   	&dev_attr_cid.attr,
> @@ -514,6 +519,7 @@ static struct attribute *mmc_std_attrs[] = {
>   	&dev_attr_serial.attr,
>   	&dev_attr_enhanced_area_offset.attr,
>   	&dev_attr_enhanced_area_size.attr,
> +	&dev_attr_raw_hw_reset_function.attr,
>   	NULL,
>   };
>
> diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
> index b460fc2..237bceb 100644
> --- a/include/linux/mmc/card.h
> +++ b/include/linux/mmc/card.h
> @@ -65,6 +65,7 @@ struct mmc_ext_csd {
>   	unsigned int		enhanced_area_size;	/* Units: KB */
>   	unsigned int		boot_size;		/* in bytes */
>   	u8			raw_partition_support;	/* 160 */
> +	u8                      raw_hw_reset_function;  /* 162 */
>   	u8			raw_erased_mem_count;	/* 181 */
>   	u8			raw_ext_csd_structure;	/* 194 */
>   	u8			raw_card_type;		/* 196 */
> diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
> index 5a794cb..233c932 100644
> --- a/include/linux/mmc/mmc.h
> +++ b/include/linux/mmc/mmc.h
> @@ -272,6 +272,7 @@ struct _mmc_csd {
>
>   #define EXT_CSD_PARTITION_ATTRIBUTE	156	/* R/W */
>   #define EXT_CSD_PARTITION_SUPPORT	160	/* RO */
> +#define EXT_CSD_RST_FUNCTION           162     /* R/W */
>   #define EXT_CSD_WR_REL_PARAM		166	/* RO */
>   #define EXT_CSD_ERASE_GROUP_DEF		175	/* R/W */
>   #define EXT_CSD_PART_CONFIG		179	/* R/W */