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
--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
