diff options
| author | Anton Vorontsov <avorontsov@ru.mvista.com> | 2008-06-17 18:17:15 +0400 |
|---|---|---|
| committer | Pierre Ossman <drzeus@drzeus.cx> | 2008-07-15 14:14:41 +0200 |
| commit | 28f52482b41edc88cdf575aa6ed414c6e116ce10 (patch) | |
| tree | 541acd881953e43113f3653ac482a83ab7afa017 | |
| parent | 150a55683b6b0ccb66aae75a10a3a514340c7c03 (diff) | |
mmc: add support for card-detection polling
Some hosts (and boards that use mmc_spi) do not use interrupts on the CD
line, so they can't trigger mmc_detect_change. We want to poll the card
and see if there was a change. 1 second poll interval seems resonable.
This patch also implements .get_cd() host operation, that could be used
by the hosts that are able to report card-detect status without need to
talk MMC.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
| -rw-r--r-- | drivers/mmc/core/core.c | 12 | ||||
| -rw-r--r-- | include/linux/mmc/host.h | 11 |
2 files changed, 20 insertions, 3 deletions
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index 01ced4c5a61..ede5d1e2e20 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -638,6 +638,9 @@ void mmc_rescan(struct work_struct *work) */ mmc_bus_put(host); + if (host->ops->get_cd && host->ops->get_cd(host) == 0) + goto out; + mmc_claim_host(host); mmc_power_up(host); @@ -652,7 +655,7 @@ void mmc_rescan(struct work_struct *work) if (!err) { if (mmc_attach_sdio(host, ocr)) mmc_power_off(host); - return; + goto out; } /* @@ -662,7 +665,7 @@ void mmc_rescan(struct work_struct *work) if (!err) { if (mmc_attach_sd(host, ocr)) mmc_power_off(host); - return; + goto out; } /* @@ -672,7 +675,7 @@ void mmc_rescan(struct work_struct *work) if (!err) { if (mmc_attach_mmc(host, ocr)) mmc_power_off(host); - return; + goto out; } mmc_release_host(host); @@ -683,6 +686,9 @@ void mmc_rescan(struct work_struct *work) mmc_bus_put(host); } +out: + if (host->caps & MMC_CAP_NEEDS_POLL) + mmc_schedule_delayed_work(&host->detect, HZ); } void mmc_start_host(struct mmc_host *host) diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 7ab962fa1d7..6188e19d233 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -51,8 +51,18 @@ struct mmc_ios { struct mmc_host_ops { void (*request)(struct mmc_host *host, struct mmc_request *req); + /* + * Avoid calling these three functions too often or in a "fast path", + * since underlaying controller might implement them in an expensive + * and/or slow way. + * + * Also note that these functions might sleep, so don't call them + * in the atomic contexts! + */ void (*set_ios)(struct mmc_host *host, struct mmc_ios *ios); int (*get_ro)(struct mmc_host *host); + int (*get_cd)(struct mmc_host *host); + void (*enable_sdio_irq)(struct mmc_host *host, int enable); }; @@ -94,6 +104,7 @@ struct mmc_host { #define MMC_CAP_SD_HIGHSPEED (1 << 3) /* Can do SD high-speed timing */ #define MMC_CAP_SDIO_IRQ (1 << 4) /* Can signal pending SDIO IRQs */ #define MMC_CAP_SPI (1 << 5) /* Talks only SPI protocols */ +#define MMC_CAP_NEEDS_POLL (1 << 6) /* Needs polling for card-detection */ /* host specific block data */ unsigned int max_seg_size; /* see blk_queue_max_segment_size */ |