[PATCH] mmc: sleep notification

Avi Shchislowski
2015-03-10T10:10:12Z

This patch is implements the new additional state of
Power_Off_Notification – SLEEP_NOTIFICATION.
Until now, the implementation of Power_Off_Notification
supported only three modes – POWERED_ON (0x01),
POWER_OFF_SHORT (0x02) and POWER_OFF_LONG (0x03).

As part of eMMC5.0 before moving to Sleep state hosts may set the
POWER_OFF_NOTIFICATION byte to SLEEP_NOTIFICATION (0x04).
After setting SLEEP_NOTIFICATION, host should wait for
the busy line to be de-asserted.
The max timeout allowed for busy line de-assertion defined
in SLEEP_NOTIFICATION_TIME byte in EXT_CSD [216].
HPI may interrupt the SLEEP_NOTIFICATION operation.
In that case POWER_OFF_NOTIFICATION byte will restore to POWERED_ON.

Signed-off-by: Alex Lemberg <alex.lemberg@sandisk.com>
Signed-off-by: Avi Shchislowski <avi.shchislowski@sandisk.com>
---
drivers/mmc/card/block.c | 19 +++++-
drivers/mmc/core/core.c | 16 +++++-
drivers/mmc/core/core.h | 2 +
drivers/mmc/core/mmc.c | 143 +++++++++++++++++++++++++++++++++++++++++++---
include/linux/mmc/card.h | 6 ++
include/linux/mmc/host.h | 1 +
include/linux/mmc/mmc.h | 2 +
7 files changed, 180 insertions(+), 9 deletions(-)

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 4409d79..f511ecc3 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -2010,9 +2010,26 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
unsigned long flags;
unsigned int cmd_flags = req ? req->cmd_flags : 0;

- if (req && !mq->mqrq_prev->req)
+ if (unlikely(req && mmc_card_mmc(card) &&
+ (card->ext_csd.power_off_notification ==
+ EXT_CSD_SLEEP_NOTIFICATION))) {
+ /* restoring the power_off_notification
+ * field's state to as it was before so
+ * that the sleep notification will be
+ * able to resume later
+ */
+ card->ext_csd.power_off_notification = EXT_CSD_POWER_ON;
+ }
+
+ if (req && !mq->mqrq_prev->req) {
/* claim host only for the first request */
mmc_get_card(card);
+ if (unlikely(req &&
+ mmc_card_doing_sleep_notify(card))) {
+ mmc_interrupt_hpi(card);
+ mmc_card_clr_sleep_notify(card);
+ }
+ }

ret = mmc_blk_part_switch(card, md);
if (ret) {
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 5bda29b..a090593 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -271,7 +271,8 @@ void mmc_start_bkops(struct mmc_card *card, bool from_exception)

BUG_ON(!card);

- if (!card->ext_csd.bkops_en || mmc_card_doing_bkops(card))
+ if (!card->ext_csd.bkops_en || mmc_card_doing_bkops(card) ||
+ mmc_card_doing_sleep_notify(card))
return;

err = mmc_read_bkops_status(card);
@@ -2630,6 +2631,19 @@ int mmc_pm_notify(struct notifier_block *notify_block,
err = host->bus_ops->pre_suspend(host);
if (!err)
break;
+ if (host->card && host->bus_ops->suspend) {
+ err = mmc_sleep_notify(host->card);
+ /* We assume that HPI was sent
+ * in case of -ETIMEDOUT error,
+ * so suspend flow can be continued
+ */
+ if (err && err != -ETIMEDOUT) {
+ pr_err("%s:sleep notify err=%d\n",
+ __func__, err);
+ return -EBUSY;
+ }
+ break;
+ }

/* Calling bus_ops->remove() with a claimed host can deadlock */
host->bus_ops->remove(host);
diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h
index d76597c..b6b4431 100644
--- a/drivers/mmc/core/core.h
+++ b/drivers/mmc/core/core.h
@@ -14,6 +14,7 @@
#include <linux/delay.h>

#define MMC_CMD_RETRIES 3
+#define MMC_SLEEP_NOTIFY_MAX_TIME 0x17

struct mmc_bus_ops {
void (*remove)(struct mmc_host *);
@@ -33,6 +34,7 @@ void mmc_attach_bus(struct mmc_host *host, const struct mmc_bus_ops *ops);
void mmc_detach_bus(struct mmc_host *host);

void mmc_init_erase(struct mmc_card *card);
+int mmc_sleep_notify(struct mmc_card *card);

void mmc_set_chip_select(struct mmc_host *host, int mode);
void mmc_set_clock(struct mmc_host *host, unsigned int hz);
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 02ad792..1d97d24 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -57,6 +57,11 @@ static const unsigned int tacc_mant[] = {
__res & __mask; \
})

+#define GET_SLEEP_NOTIFY_TIME(value) \
+ (10 * (1 << (unsigned int)(value)))
+#define GET_SLEEP_NOTIFY_TIME_MSEC(value) \
+ (DIV_ROUND_UP(GET_SLEEP_NOTIFY_TIME(value), 1000))
+
/*
* Given the decoded CSD structure, decode the raw CID to our CID structure.
*/
@@ -571,6 +576,8 @@ static int mmc_decode_ext_csd(struct mmc_card *card, u8 *ext_csd)
card->ext_csd.ffu_capable =
(ext_csd[EXT_CSD_SUPPORTED_MODE] & 0x1) &&
!(ext_csd[EXT_CSD_FW_CONFIG] & 0x1);
+ card->ext_csd.sleep_notify_time =
+ ext_csd[EXT_CSD_SLEEP_NOTIFICATION_TIME];
}
out:
return err;
@@ -1468,6 +1475,15 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
card->ext_csd.hpi_en = 1;
}

+ /* sleep notify enable/disable for eMMC 5.0 and above */
+ if ((card->ext_csd.rev >= 7) && card->ext_csd.hpi_en &&
+ (card->host->caps2 & MMC_CAP2_SLEEP_NOTIFY) &&
+ card->ext_csd.sleep_notify_time > 0 &&
+ card->ext_csd.sleep_notify_time <=
+ MMC_SLEEP_NOTIFY_MAX_TIME) {
+ card->can_sleep_notify = 1;
+ }
+
/*
* If cache size is higher than 0, this indicates
* the existence of cache and it can be turned on.
@@ -1576,6 +1592,33 @@ static int mmc_sleep(struct mmc_host *host)
return err;
}

+/*
+ * check if device is in program state (busy)
+ */
+static bool mmc_device_prg_state(struct mmc_card *card)
+{
+ int rc;
+ u32 status;
+ bool state;
+
+ mmc_get_card(card);
+ rc = mmc_send_status(card, &status);
+ if (rc) {
+ pr_err("%s: Get card status fail. rc=%d\n",
+ mmc_hostname(card->host), rc);
+ state = false;
+ goto out;
+ }
+
+ if (R1_CURRENT_STATE(status) == R1_STATE_PRG)
+ state = true;
+ else
+ state = false;
+out:
+ mmc_put_card(card);
+ return state;
+}
+
static int mmc_can_poweroff_notify(const struct mmc_card *card)
{
return card &&
@@ -1585,22 +1628,108 @@ static int mmc_can_poweroff_notify(const struct mmc_card *card)

static int mmc_poweroff_notify(struct mmc_card *card, unsigned int notify_type)
{
- unsigned int timeout = card->ext_csd.generic_cmd6_time;
+ unsigned int timeout_ms = card->ext_csd.generic_cmd6_time;
int err;
+ bool use_busy_signal;

/* Use EXT_CSD_POWER_OFF_SHORT as default notification type. */
if (notify_type == EXT_CSD_POWER_OFF_LONG)
- timeout = card->ext_csd.power_off_longtime;
+ timeout_ms = card->ext_csd.power_off_longtime;
+ else if (notify_type == EXT_CSD_SLEEP_NOTIFICATION) {
+ /* calculate the maximum timeout for the
+ * switch command when notifying the device
+ * that it is about to move to sleep */
+ timeout_ms = GET_SLEEP_NOTIFY_TIME_MSEC(
+ card->ext_csd.sleep_notify_time);
+ }

+ /* do not wait on busy signal in case of
+ * Sleep Notification - to let host get
+ * another requests
+ */
+ use_busy_signal = (notify_type == EXT_CSD_SLEEP_NOTIFICATION) ?
+ false : true;
err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
EXT_CSD_POWER_OFF_NOTIFICATION,
- notify_type, timeout, true, false, false);
- if (err)
+ notify_type, timeout_ms,
+ use_busy_signal, false, false);
+ if (!err) {
+ card->ext_csd.power_off_notification = notify_type;
+ } else {
pr_err("%s: Power Off Notification timed out, %u\n",
- mmc_hostname(card->host), timeout);
+ mmc_hostname(card->host), timeout_ms);
+ }
+
+ return err;
+}

- /* Disable the power off notification after the switch operation. */
- card->ext_csd.power_off_notification = EXT_CSD_NO_POWER_NOTIFICATION;
+int mmc_sleep_notify(struct mmc_card *card)
+{
+ int err = 0;
+ bool is_busy = 0;
+ unsigned long prg_wait = 0;
+
+ if (!card->can_sleep_notify || !mmc_can_poweroff_notify(card))
+ return 0;
+
+ if (!mmc_card_doing_sleep_notify(card)) {
+ mmc_get_card(card);
+ mmc_card_set_sleep_notify(card);
+ err = mmc_poweroff_notify(card,
+ EXT_CSD_SLEEP_NOTIFICATION);
+ mmc_put_card(card);
+ if (err) {
+ pr_err("%s: mmc_poweroff_notify failed with %d\n",
+ __func__, err);
+ goto out;
+ }
+
+ prg_wait = jiffies +
+ msecs_to_jiffies(GET_SLEEP_NOTIFY_TIME_MSEC(
+ card->ext_csd.sleep_notify_time));
+ }
+
+ /*
+ * Loop will run until:
+ * 1. Device is no more in Busy state
+ * 2. Sleep notification is not interrupted by HPI & IO request
+ */
+ do {
+ /* added some delay to avoid sending card status too often */
+ msleep(20);
+ err = 0;
+ /* Stop polling in case sleep notification was HPIed already */
+ if (!mmc_card_doing_sleep_notify(card)) {
+ is_busy = mmc_device_prg_state(card);
+ if (is_busy)
+ err = -EBUSY;
+ break;
+ }
+ is_busy = mmc_device_prg_state(card);
+ if (is_busy && time_after(jiffies, prg_wait)) {
+ /*
+ * making sure we are still in busy before
+ * sending HPI due to timeout error
+ */
+ is_busy = mmc_device_prg_state(card);
+ if (is_busy) {
+ if (mmc_card_doing_sleep_notify(card)) {
+ card->ext_csd.power_off_notification =
+ EXT_CSD_POWER_ON;
+ mmc_interrupt_hpi(card);
+ }
+ err = -ETIMEDOUT;
+ break;
+ }
+ }
+ } while (is_busy);
+
+out:
+ mmc_card_clr_sleep_notify(card);
+ if (err) {
+ pr_err("%s: mmc_poweroff_notify for sleep failed with %d\n",
+ mmc_hostname(card->host), err);
+ }

return err;
}
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 4d69c00..6998344 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -62,6 +62,7 @@ struct mmc_ext_csd {
unsigned int sa_timeout; /* Units: 100ns */
unsigned int generic_cmd6_time; /* Units: 10ms */
unsigned int power_off_longtime; /* Units: ms */
+ unsigned int sleep_notify_time; /* Units: us */
u8 power_off_notification; /* state */
unsigned int hs_max_dtr;
unsigned int hs200_max_dtr;
@@ -262,6 +263,7 @@ struct mmc_card {
#define MMC_CARD_REMOVED (1<<4) /* card has been removed */
#define MMC_STATE_DOING_BKOPS (1<<5) /* card is doing BKOPS */
#define MMC_STATE_SUSPENDED (1<<6) /* card is suspended */
+#define MMC_STATE_SLEEP_NOTIFY (1<<7) /* card in sleep notify */
unsigned int quirks; /* card quirks */
#define MMC_QUIRK_LENIENT_FN0 (1<<0) /* allow SDIO FN0 writes outside of the VS CCCR range */
#define MMC_QUIRK_BLKSZ_FOR_BYTE_MODE (1<<1) /* use func->cur_blksize */
@@ -309,6 +311,7 @@ struct mmc_card {
struct dentry *debugfs_root;
struct mmc_part part[MMC_NUM_PHY_PARTITION]; /* physical partitions */
unsigned int nr_parts;
+ u8 can_sleep_notify; /* sleep_notify on/off */
};

/*
@@ -427,6 +430,7 @@ static inline void __maybe_unused remove_quirk(struct mmc_card *card, int data)
#define mmc_card_removed(c) ((c) && ((c)->state & MMC_CARD_REMOVED))
#define mmc_card_doing_bkops(c) ((c)->state & MMC_STATE_DOING_BKOPS)
#define mmc_card_suspended(c) ((c)->state & MMC_STATE_SUSPENDED)
+#define mmc_card_doing_sleep_notify(c) ((c)->state & MMC_STATE_SLEEP_NOTIFY)

#define mmc_card_set_present(c) ((c)->state |= MMC_STATE_PRESENT)
#define mmc_card_set_readonly(c) ((c)->state |= MMC_STATE_READONLY)
@@ -437,6 +441,8 @@ static inline void __maybe_unused remove_quirk(struct mmc_card *card, int data)
#define mmc_card_clr_doing_bkops(c) ((c)->state &= ~MMC_STATE_DOING_BKOPS)
#define mmc_card_set_suspended(c) ((c)->state |= MMC_STATE_SUSPENDED)
#define mmc_card_clr_suspended(c) ((c)->state &= ~MMC_STATE_SUSPENDED)
+#define mmc_card_set_sleep_notify(c) ((c)->state |= MMC_STATE_SLEEP_NOTIFY)
+#define mmc_card_clr_sleep_notify(c) ((c)->state &= ~MMC_STATE_SLEEP_NOTIFY)

/*
* Quirk add/remove for MMC products.
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 9f32270..4c0542a 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -291,6 +291,7 @@ struct mmc_host {
MMC_CAP2_HS400_1_2V)
#define MMC_CAP2_HSX00_1_2V (MMC_CAP2_HS200_1_2V_SDR | MMC_CAP2_HS400_1_2V)
#define MMC_CAP2_SDIO_IRQ_NOTHREAD (1 << 17)
+#define MMC_CAP2_SLEEP_NOTIFY (1 << 18) /* sleep notify supported */

mmc_pm_flag_t pm_caps; /* supported pm features */

diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index 49ad7a9..69bda9a 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -314,6 +314,7 @@ struct _mmc_csd {
#define EXT_CSD_PWR_CL_52_360 202 /* RO */
#define EXT_CSD_PWR_CL_26_360 203 /* RO */
#define EXT_CSD_SEC_CNT 212 /* RO, 4 bytes */
+#define EXT_CSD_SLEEP_NOTIFICATION_TIME 216 /* RO */
#define EXT_CSD_S_A_TIMEOUT 217 /* RO */
#define EXT_CSD_REL_WR_SEC_C 222 /* RO */
#define EXT_CSD_HC_WP_GRP_SIZE 221 /* RO */
@@ -408,6 +409,7 @@ struct _mmc_csd {
#define EXT_CSD_POWER_ON 1
#define EXT_CSD_POWER_OFF_SHORT 2
#define EXT_CSD_POWER_OFF_LONG 3
+#define EXT_CSD_SLEEP_NOTIFICATION 4

#define EXT_CSD_PWR_CL_8BIT_MASK 0xF0 /* 8 bit PWR CLS */
#define EXT_CSD_PWR_CL_4BIT_MASK 0x0F /* 8 bit PWR CLS */
--
1.7.9.5