2012/2/6 Jaehoon Chung <jh80.chung@xxxxxxxxxxx>:
> Hi Mr.Jeon.
>
> On 02/06/2012 01:19 PM, Namjae Jeon wrote:
>
>> Hi. Jaehoon.
>>
>> I have questions.
>>
>> 1. Would you explain why we need on/off function of this CMD23 at runtime ?
>
> Now..operation mode is set at compile time..That means if we use the pre-defined mode,
> must always use the pre-defined mode.
> Packed-cmd, Data-tag, Context-Id..etc..almost features need to use CMD23.
> But in vendor side, some card need to use the open-ended in order to update the firmware code.
> (or not)
> If we use the cmd23, to update the firmware code maybe need to rebuild..it's worthless.
> So i added this patch.
First, Thanks for your explaination.
If possible, you can add this description in patch header so that the
other understand.
>
>> 2. While frequently reading/writing, Have you tested by being
>> enabling/disbling CMD23 using this function ?
>
> Yes..i tested that case..and working well.
>
>> 3. Why is irq disable needed when calling mmc_change_operation_mode ?
>> If are we just using spin_lock ?
>
> that value is how we process the request, so i think that need spin_lock_irq().
> Well..spin_lock()? i think that..
if it can replace spin_lock, it is better to avoid using irq disble.
if surely needed, it should be explained.
>
>> 4. When do we use host->pre_defined_op value after setting it ?
>
> Just the setting value..to show the value..any other opinion.
> If you have the other approach, i will change.
I didn't find this value usage in patch. if it is not using in this
patch and other elsewhere, plz remove it.
>
> Best Regards,
> Jaehoon Chung
>
>>
>> Thanks.
>>
>> 2012/2/6 Jaehoon Chung <jh80.chung@xxxxxxxxxxx>:
>>> This patch is support the sysfs for operation mode.
>>>
>>> There are two operation modes(open-ended/pre-defined).
>>> Now, operation mode is selected only one at the compile time.
>>>
>>> But using this patch, we can change the operation mode with node at runtime.
>>>
>>> * pre-defined mode
>>> echo 1 > /sys/class/mmc_host/mmc0/pre_defined_op
>>> * open-ended mode
>>> echo 0 > /sys/class/mmc_host/mmc0/pre_defined_op
>>>
>>> Signed-off-by: Jaehoon Chung <jh80.chung@xxxxxxxxxxx>
>>> Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
>>> ---
>>> Changelog V4:
>>> - Add the explanation in Documentation/mmc/mmc-dev-attrs.txt
>>> Changelog V3:
>>> - Add the mmc_change_operation_mode()
>>> Changelog v2:
>>> - Add the check point in mmc_cmd23_store()
>>> (If host controller didn't support CMD23, need not to change the ops-mode.)
>>>
>>> Documentation/mmc/mmc-dev-attrs.txt | 16 ++++++++++++++
>>> drivers/mmc/card/block.c | 19 +++++++++++++++++
>>> drivers/mmc/core/host.c | 39 +++++++++++++++++++++++++++++++++++
>>> include/linux/mmc/card.h | 1 +
>>> include/linux/mmc/host.h | 3 ++
>>> 5 files changed, 78 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/Documentation/mmc/mmc-dev-attrs.txt b/Documentation/mmc/mmc-dev-attrs.txt
>>> index 22ae844..e7ba3b6 100644
>>> --- a/Documentation/mmc/mmc-dev-attrs.txt
>>> +++ b/Documentation/mmc/mmc-dev-attrs.txt
>>> @@ -74,3 +74,19 @@ This attribute appears only if CONFIG_MMC_CLKGATE is enabled.
>>> clkgate_delay Tune the clock gating delay with desired value in milliseconds.
>>>
>>> echo <desired delay> > /sys/class/mmc_host/mmcX/clkgate_delay
>>> +
>>> +SD and MMC Operation Mode Attribute
>>> +==========================================
>>> +
>>> +SD and MMC can support the two operation mode.
>>> +(Pre-defined(CMD23)/Open-ended operation mode)
>>> +
>>> +This attribute can change the operation mode at runtime if card is supported the CMD23.
>>> +
>>> + pre_defined_op Support the pre-defined mode if set 1.
>>> +
>>> +1) Open-ended mode
>>> +echo 0 > /sys/class/mmc_host/mmcX/pre_defined_op
>>> +
>>> +2) Pre-defined mode
>>> +echo 1 > /sys/class/mmc_host/mmcX/pre_defined_op
>>> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
>>> index a7c75d8..2c1981c 100644
>>> --- a/drivers/mmc/card/block.c
>>> +++ b/drivers/mmc/card/block.c
>>> @@ -1766,6 +1766,25 @@ static const struct mmc_fixup blk_fixups[] =
>>> END_FIXUP
>>> };
>>>
>>> +void mmc_change_operation_mode(struct mmc_card *card, int val)
>>> +{
>>> + struct mmc_blk_data *md = mmc_get_drvdata(card);
>>> +
>>> + if (mmc_host_cmd23(card->host)) {
>>> + if (mmc_card_mmc(card) ||
>>> + (mmc_card_sd(card) &&
>>> + card->scr.cmds & SD_SCR_CMD23_SUPPORT)) {
>>> + if (val) {
>>> + md->flags |= MMC_BLK_CMD23;
>>> + card->host->pre_defined_op = val;
>>> + } else {
>>> + md->flags &= ~MMC_BLK_CMD23;
>>> + card->host->pre_defined_op = val;
>>> + }
>>> + }
>>> + }
>>> +}
>>> +
>>> static int mmc_blk_probe(struct mmc_card *card)
>>> {
>>> struct mmc_blk_data *md, *part_md;
>>> diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
>>> index 30055f2..7dab0dc 100644
>>> --- a/drivers/mmc/core/host.c
>>> +++ b/drivers/mmc/core/host.c
>>> @@ -293,6 +293,41 @@ static inline void mmc_host_clk_sysfs_init(struct mmc_host *host)
>>>
>>> #endif
>>>
>>> +static ssize_t mmc_cmd23_show(struct device *dev,
>>> + struct device_attribute *attr, char *buf)
>>> +{
>>> + struct mmc_host *host = cls_dev_to_mmc_host(dev);
>>> + return snprintf(buf, PAGE_SIZE, "%d\n", host->pre_defined_op);
>>> +}
>>> +
>>> +static ssize_t mmc_cmd23_store(struct device *dev,
>>> + struct device_attribute *attr, const char *buf, size_t count)
>>> +{
>>> + struct mmc_host *host = cls_dev_to_mmc_host(dev);
>>> + int value;
>>> + unsigned long flags;
>>> +
>>> + if (kstrtoint(buf, 0, &value))
>>> + return -EINVAL;
>>> +
>>> + spin_lock_irqsave(&host->lock, flags);
>>> + mmc_change_operation_mode(host->card, value);
>>> + spin_unlock_irqrestore(&host->lock, flags);
>>> + return count;
>>> +}
>>> +
>>> +static inline void mmc_host_cmd23_sysfs_init(struct mmc_host *host)
>>> +{
>>> + host->pre_defined_attr.show = mmc_cmd23_show;
>>> + host->pre_defined_attr.store = mmc_cmd23_store;
>>> + sysfs_attr_init(&host->pre_defined_attr.attr);
>>> + host->pre_defined_attr.attr.name = "pre_defined_op";
>>> + host->pre_defined_attr.attr.mode = S_IRUGO | S_IWUSR;
>>> + if (device_create_file(&host->class_dev, &host->pre_defined_attr))
>>> + pr_err("%s: Failed to create pre_defined_op sysfs entry\n",
>>> + mmc_hostname(host));
>>> +}
>>> +
>>> /**
>>> * mmc_alloc_host - initialise the per-host structure.
>>> * @extra: sizeof private data structure
>>> @@ -381,6 +416,10 @@ int mmc_add_host(struct mmc_host *host)
>>> #endif
>>> mmc_host_clk_sysfs_init(host);
>>>
>>> + if (host->caps & MMC_CAP_CMD23)
>>> + host->pre_defined_op = 1;
>>> + mmc_host_cmd23_sysfs_init(host);
>>> +
>>> mmc_start_host(host);
>>> register_pm_notifier(&host->pm_notify);
>>>
>>> diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
>>> index 1a1ca71..b36d408 100644
>>> --- a/include/linux/mmc/card.h
>>> +++ b/include/linux/mmc/card.h
>>> @@ -489,5 +489,6 @@ extern void mmc_unregister_driver(struct mmc_driver *);
>>>
>>> extern void mmc_fixup_device(struct mmc_card *card,
>>> const struct mmc_fixup *table);
>>> +extern void mmc_change_operation_mode(struct mmc_card *card, int val);
>>>
>>> #endif /* LINUX_MMC_CARD_H */
>>> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
>>> index 20d7c82..59a30bf 100644
>>> --- a/include/linux/mmc/host.h
>>> +++ b/include/linux/mmc/host.h
>>> @@ -259,6 +259,9 @@ struct mmc_host {
>>> MMC_CAP2_HS200_1_2V_SDR)
>>> #define MMC_CAP2_BROKEN_VOLTAGE (1 << 7) /* Use the broken voltage */
>>>
>>> + struct device_attribute pre_defined_attr;
>>> + int pre_defined_op; /* CMD23 should be use or not */
>>> +
>>> mmc_pm_flag_t pm_caps; /* supported pm features */
>>> unsigned int power_notify_type;
>>> #define MMC_HOST_PW_NOTIFY_NONE 0
>>> --
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