lkml.org 
[lkml]   [2008]   [Jun]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[PATCH 1/3] 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>
    ---
    drivers/mmc/core/core.c | 12 +++++++++---
    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 01ced4c..ede5d1e 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 7ab962f..6188e19 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 */
    --
    1.5.5.4


    \
     
     \ /
      Last update: 2008-06-17 16:19    [W:0.022 / U:1.220 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site