mmc: sdhci: add platform get_max_timeout_count hook

Currently the max timeout count is hardcode to 1 << 27 for calcuate
the max_busy_timeout, however, for some platforms the max timeout
count may not be 1 << 27, e.g. i.MX uSDHC is 1 << 28.
Thus 1 << 27 is not correct for such platform.

It is also possible that other platforms may have different values.
To be flexible, we add a get_max_timeout_count hook to get the correct
maximum timeout value for these platforms.

Reviewed-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Dong Aisheng <b29396@freescale.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 4cc2ff9..2ba9c4b 100644 (file)
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1197,7 +1197,10 @@ clock_set:
                if (host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK) {
                        host->timeout_clk = host->mmc->actual_clock / 1000;
                        host->mmc->max_busy_timeout =
-                               (1 << 27) / host->timeout_clk;
+                                       host->ops->get_max_timeout_count ?
+                                       host->ops->get_max_timeout_count(host) :
+                                       1 << 27;
+                       host->mmc->max_busy_timeout /= host->timeout_clk;
                }
        }
 
@@ -2937,7 +2940,9 @@ int sdhci_add_host(struct sdhci_host *host)
        if (host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)
                host->timeout_clk = mmc->f_max / 1000;
 
-       mmc->max_busy_timeout = (1 << 27) / host->timeout_clk;
+       mmc->max_busy_timeout = host->ops->get_max_timeout_count ?
+                       host->ops->get_max_timeout_count(host) : 1 << 27;
+       mmc->max_busy_timeout /= host->timeout_clk;
 
        mmc->caps |= MMC_CAP_SDIO_IRQ | MMC_CAP_ERASE | MMC_CAP_CMD23;
        mmc->caps2 |= MMC_CAP2_SDIO_IRQ_NOTHREAD;

diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 4a5cd5e..b130509 100644 (file)
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -281,6 +281,7 @@ struct sdhci_ops {
        unsigned int    (*get_max_clock)(struct sdhci_host *host);
        unsigned int    (*get_min_clock)(struct sdhci_host *host);
        unsigned int    (*get_timeout_clock)(struct sdhci_host *host);
+       unsigned int    (*get_max_timeout_count)(struct sdhci_host *host);
        void            (*set_bus_width)(struct sdhci_host *host, int width);
        void (*platform_send_init_74_clocks)(struct sdhci_host *host,
                                             u8 power_mode);