diff options
| -rw-r--r-- | drivers/mmc/core/core.c | 177 | ||||
| -rw-r--r-- | drivers/mmc/core/host.c | 1 | ||||
| -rw-r--r-- | drivers/mmc/core/host.h | 2 | ||||
| -rw-r--r-- | include/linux/mmc/host.h | 47 |
4 files changed, 221 insertions, 6 deletions
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index e22d2b5576e..fb24a096dba 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -344,6 +344,101 @@ unsigned int mmc_align_data_size(struct mmc_card *card, unsigned int sz) EXPORT_SYMBOL(mmc_align_data_size); /** + * mmc_host_enable - enable a host. + * @host: mmc host to enable + * + * Hosts that support power saving can use the 'enable' and 'disable' + * methods to exit and enter power saving states. For more information + * see comments for struct mmc_host_ops. + */ +int mmc_host_enable(struct mmc_host *host) +{ + if (!(host->caps & MMC_CAP_DISABLE)) + return 0; + + if (host->en_dis_recurs) + return 0; + + if (host->nesting_cnt++) + return 0; + + cancel_delayed_work_sync(&host->disable); + + if (host->enabled) + return 0; + + if (host->ops->enable) { + int err; + + host->en_dis_recurs = 1; + err = host->ops->enable(host); + host->en_dis_recurs = 0; + + if (err) { + pr_debug("%s: enable error %d\n", + mmc_hostname(host), err); + return err; + } + } + host->enabled = 1; + return 0; +} +EXPORT_SYMBOL(mmc_host_enable); + +static int mmc_host_do_disable(struct mmc_host *host, int lazy) +{ + if (host->ops->disable) { + int err; + + host->en_dis_recurs = 1; + err = host->ops->disable(host, lazy); + host->en_dis_recurs = 0; + + if (err < 0) { + pr_debug("%s: disable error %d\n", + mmc_hostname(host), err); + return err; + } + if (err > 0) { + unsigned long delay = msecs_to_jiffies(err); + + mmc_schedule_delayed_work(&host->disable, delay); + } + } + host->enabled = 0; + return 0; +} + +/** + * mmc_host_disable - disable a host. + * @host: mmc host to disable + * + * Hosts that support power saving can use the 'enable' and 'disable' + * methods to exit and enter power saving states. For more information + * see comments for struct mmc_host_ops. + */ +int mmc_host_disable(struct mmc_host *host) +{ + int err; + + if (!(host->caps & MMC_CAP_DISABLE)) + return 0; + + if (host->en_dis_recurs) + return 0; + + if (--host->nesting_cnt) + return 0; + + if (!host->enabled) + return 0; + + err = mmc_host_do_disable(host, 0); + return err; +} +EXPORT_SYMBOL(mmc_host_disable); + +/** * __mmc_claim_host - exclusively claim a host * @host: mmc host to claim * @abort: whether or not the operation should be aborted @@ -379,11 +474,81 @@ int __mmc_claim_host(struct mmc_host *host, atomic_t *abort) wake_up(&host->wq); spin_unlock_irqrestore(&host->lock, flags); remove_wait_queue(&host->wq, &wait); + if (!stop) + mmc_host_enable(host); return stop; } EXPORT_SYMBOL(__mmc_claim_host); +static int mmc_try_claim_host(struct mmc_host *host) +{ + int claimed_host = 0; + unsigned long flags; + + spin_lock_irqsave(&host->lock, flags); + if (!host->claimed) { + host->claimed = 1; + claimed_host = 1; + } + spin_unlock_irqrestore(&host->lock, flags); + return claimed_host; +} + +static void mmc_do_release_host(struct mmc_host *host) +{ + unsigned long flags; + + spin_lock_irqsave(&host->lock, flags); + host->claimed = 0; + spin_unlock_irqrestore(&host->lock, flags); + + wake_up(&host->wq); +} + +void mmc_host_deeper_disable(struct work_struct *work) +{ + struct mmc_host *host = + container_of(work, struct mmc_host, disable.work); + + /* If the host is claimed then we do not want to disable it anymore */ + if (!mmc_try_claim_host(host)) + return; + mmc_host_do_disable(host, 1); + mmc_do_release_host(host); +} + +/** + * mmc_host_lazy_disable - lazily disable a host. + * @host: mmc host to disable + * + * Hosts that support power saving can use the 'enable' and 'disable' + * methods to exit and enter power saving states. For more information + * see comments for struct mmc_host_ops. + */ +int mmc_host_lazy_disable(struct mmc_host *host) +{ + if (!(host->caps & MMC_CAP_DISABLE)) + return 0; + + if (host->en_dis_recurs) + return 0; + + if (--host->nesting_cnt) + return 0; + + if (!host->enabled) + return 0; + + if (host->disable_delay) { + mmc_schedule_delayed_work(&host->disable, + msecs_to_jiffies(host->disable_delay)); + return 0; + } else + return mmc_host_do_disable(host, 1); +} +EXPORT_SYMBOL(mmc_host_lazy_disable); + /** * mmc_release_host - release a host * @host: mmc host to release @@ -393,15 +558,11 @@ EXPORT_SYMBOL(__mmc_claim_host); */ void mmc_release_host(struct mmc_host *host) { - unsigned long flags; - WARN_ON(!host->claimed); - spin_lock_irqsave(&host->lock, flags); - host->claimed = 0; - spin_unlock_irqrestore(&host->lock, flags); + mmc_host_lazy_disable(host); - wake_up(&host->wq); + mmc_do_release_host(host); } EXPORT_SYMBOL(mmc_release_host); @@ -953,6 +1114,8 @@ void mmc_stop_host(struct mmc_host *host) spin_unlock_irqrestore(&host->lock, flags); #endif + if (host->caps & MMC_CAP_DISABLE) + cancel_delayed_work(&host->disable); cancel_delayed_work(&host->detect); mmc_flush_scheduled_work(); @@ -981,6 +1144,8 @@ void mmc_stop_host(struct mmc_host *host) */ int mmc_suspend_host(struct mmc_host *host, pm_message_t state) { + if (host->caps & MMC_CAP_DISABLE) + cancel_delayed_work(&host->disable); cancel_delayed_work(&host->detect); mmc_flush_scheduled_work(); diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c index 5e945e64ead..a268d12f1af 100644 --- a/drivers/mmc/core/host.c +++ b/drivers/mmc/core/host.c @@ -83,6 +83,7 @@ struct mmc_host *mmc_alloc_host(int extra, struct device *dev) spin_lock_init(&host->lock); init_waitqueue_head(&host->wq); INIT_DELAYED_WORK(&host->detect, mmc_rescan); + INIT_DELAYED_WORK_DEFERRABLE(&host->disable, mmc_host_deeper_disable); /* * By default, hosts do not support SGIO or large requests. diff --git a/drivers/mmc/core/host.h b/drivers/mmc/core/host.h index c2dc3d2d9f9..8c87e1109a3 100644 --- a/drivers/mmc/core/host.h +++ b/drivers/mmc/core/host.h @@ -14,5 +14,7 @@ int mmc_register_host_class(void); void mmc_unregister_host_class(void); +void mmc_host_deeper_disable(struct work_struct *work); + #endif diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 3e7615e9087..338a9b3d51e 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -51,6 +51,35 @@ struct mmc_ios { }; struct mmc_host_ops { + /* + * Hosts that support power saving can use the 'enable' and 'disable' + * methods to exit and enter power saving states. 'enable' is called + * when the host is claimed and 'disable' is called (or scheduled with + * a delay) when the host is released. The 'disable' is scheduled if + * the disable delay set by 'mmc_set_disable_delay()' is non-zero, + * otherwise 'disable' is called immediately. 'disable' may be + * scheduled repeatedly, to permit ever greater power saving at the + * expense of ever greater latency to re-enable. Rescheduling is + * determined by the return value of the 'disable' method. A positive + * value gives the delay in milliseconds. + * + * In the case where a host function (like set_ios) may be called + * with or without the host claimed, enabling and disabling can be + * done directly and will nest correctly. Call 'mmc_host_enable()' and + * 'mmc_host_lazy_disable()' for this purpose, but note that these + * functions must be paired. + * + * Alternatively, 'mmc_host_enable()' may be paired with + * 'mmc_host_disable()' which calls 'disable' immediately. In this + * case the 'disable' method will be called with 'lazy' set to 0. + * This is mainly useful for error paths. + * + * Because lazy disable may be called from a work queue, the 'disable' + * method must claim the host when 'lazy' != 0, which will work + * correctly because recursion is detected and handled. + */ + int (*enable)(struct mmc_host *host); + int (*disable)(struct mmc_host *host, int lazy); void (*request)(struct mmc_host *host, struct mmc_request *req); /* * Avoid calling these three functions too often or in a "fast path", @@ -118,6 +147,7 @@ struct mmc_host { #define MMC_CAP_SPI (1 << 4) /* Talks only SPI protocols */ #define MMC_CAP_NEEDS_POLL (1 << 5) /* Needs polling for card-detection */ #define MMC_CAP_8_BIT_DATA (1 << 6) /* Can the host do 8 bit transfers */ +#define MMC_CAP_DISABLE (1 << 7) /* Can the host be disabled */ /* host specific block data */ unsigned int max_seg_size; /* see blk_queue_max_segment_size */ @@ -142,6 +172,13 @@ struct mmc_host { unsigned int removed:1; /* host is being removed */ #endif + /* Only used with MMC_CAP_DISABLE */ + int enabled; /* host is enabled */ + int nesting_cnt; /* "enable" nesting count */ + int en_dis_recurs; /* detect recursion */ + unsigned int disable_delay; /* disable delay in msecs */ + struct delayed_work disable; /* disabling work */ + struct mmc_card *card; /* device attached to this host */ wait_queue_head_t wq; @@ -197,5 +234,15 @@ struct regulator; int mmc_regulator_get_ocrmask(struct regulator *supply); int mmc_regulator_set_ocr(struct regulator *supply, unsigned short vdd_bit); +int mmc_host_enable(struct mmc_host *host); +int mmc_host_disable(struct mmc_host *host); +int mmc_host_lazy_disable(struct mmc_host *host); + +static inline void mmc_set_disable_delay(struct mmc_host *host, + unsigned int disable_delay) +{ + host->disable_delay = disable_delay; +} + #endif |