[PATCH 2/3] mmc_spi: add support for card-detection polling

From: Anton Vorontsov
Date: Thu May 22 2008 - 14:19:15 EST


If platform_data lacks init() callback (solely used to request
card-detect interrupt), we mark the host as MMC_CAP_NEEDS_POLL.

get_cd() host operation provided to optimize polling.

Signed-off-by: Anton Vorontsov <avorontsov@xxxxxxxxxxxxx>
---
drivers/mmc/host/mmc_spi.c | 18 ++++++++++++++++--
include/linux/spi/mmc_spi.h | 6 ++++++
2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/mmc_spi.c b/drivers/mmc/host/mmc_spi.c
index 3550858..f0f86b1 100644
--- a/drivers/mmc/host/mmc_spi.c
+++ b/drivers/mmc/host/mmc_spi.c
@@ -1131,11 +1131,20 @@ static int mmc_spi_get_ro(struct mmc_host *mmc)
return 0;
}

+static int mmc_spi_get_cd(struct mmc_host *mmc)
+{
+ struct mmc_spi_host *host = mmc_priv(mmc);
+
+ if (host->pdata && host->pdata->get_cd)
+ return host->pdata->get_cd(mmc->parent);
+ return -ENOSYS;
+}

static const struct mmc_host_ops mmc_spi_ops = {
.request = mmc_spi_request,
.set_ios = mmc_spi_set_ios,
.get_ro = mmc_spi_get_ro,
+ .get_cd = mmc_spi_get_cd,
};


@@ -1323,13 +1332,18 @@ static int mmc_spi_probe(struct spi_device *spi)
if (status != 0)
goto fail_add_host;

- dev_info(&spi->dev, "SD/MMC host %s%s%s%s\n",
+ if (host->pdata && !host->pdata->init)
+ mmc->caps |= MMC_CAP_NEEDS_POLL;
+
+ dev_info(&spi->dev, "SD/MMC host %s%s%s%s%s\n",
mmc->class_dev.bus_id,
host->dma_dev ? "" : ", no DMA",
(host->pdata && host->pdata->get_ro)
? "" : ", no WP",
(host->pdata && host->pdata->setpower)
- ? "" : ", no poweroff");
+ ? "" : ", no poweroff",
+ (mmc->caps & MMC_CAP_NEEDS_POLL)
+ ? ", cd polling" : "");
return 0;

fail_add_host:
diff --git a/include/linux/spi/mmc_spi.h b/include/linux/spi/mmc_spi.h
index d5ca78b..23c6923 100644
--- a/include/linux/spi/mmc_spi.h
+++ b/include/linux/spi/mmc_spi.h
@@ -23,6 +23,12 @@ struct mmc_spi_platform_data {
/* sense switch on sd cards */
int (*get_ro)(struct device *);

+ /*
+ * If board does not use CD interrupts, driver can optimize polling
+ * using this function.
+ */
+ int (*get_cd)(struct device *);
+
/* how long to debounce card detect, in msecs */
u16 detect_delay;

--
1.5.5.1

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