mmc: core: Allow hosts to specify non-support for SD commands

There are host drivers which needs to valdiate for non-supported SD
commands and returnn error code for such requests.

To improve and simplify the behaviour, let's invent MMC_CAP2_NO_SD
which these host drivers can set to tell the mmc core to skip sending SD
commands during card initialization.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

2 files changed, 7 insertions, 3 deletions

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 1d24b3ad2a5d..4c823df8deb4 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -2498,15 +2498,18 @@ static int mmc_rescan_try_freq(struct mmc_host *host, unsigned freq)
 
         mmc_go_idle(host);
 
-        mmc_send_if_cond(host, host->ocr_avail);
+        if (!(host->caps2 & MMC_CAP2_NO_SD))
+                mmc_send_if_cond(host, host->ocr_avail);
 
         /* Order's important: probe SDIO, then SD, then MMC */
         if (!(host->caps2 & MMC_CAP2_NO_SDIO))
                 if (!mmc_attach_sdio(host))
                         return 0;
 
-        if (!mmc_attach_sd(host))
-                return 0;
+        if (!(host->caps2 & MMC_CAP2_NO_SD))
+                if (!mmc_attach_sd(host))
+                        return 0;
+
         if (!mmc_attach_mmc(host))
                 return 0;
 
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index d72c0c34c21d..c22476d23b84 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -309,6 +309,7 @@ struct mmc_host {
 #define MMC_CAP2_NO_WRITE_PROTECT (1 << 18)     /* No physical write protect pin, assume that card is always read-write */
 #define MMC_CAP2_NO_SDIO        (1 << 19)       /* Do not send SDIO commands during initialization */
 #define MMC_CAP2_HS400_ES       (1 << 20)       /* Host supports enhanced strobe */
+#define MMC_CAP2_NO_SD          (1 << 21)       /* Do not send SD commands during initialization */
 
         mmc_pm_flag_t           pm_caps;        /* supported pm features */