mmc: sdio: Fix SDIO 3.0 UHS-I initialization sequence

According to UHS-I initialization sequence for SDIO 3.0 cards,
the host must set bit[24] (S18R) of OCR register during OCR
handshake to know whether the SDIO card is capable of doing
1.8V I/O.

Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Reviewed-by: Johan Rudholm <johan.rudholm@stericsson.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index 34ad4c877c1ffbaf33fe7d7a262215605df55d84..9565d38d91a440233f76312f65750c127239cdca 100644 (file)
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -157,10 +157,7 @@ static int sdio_read_cccr(struct mmc_card *card, u32 ocr)
                        if (ret)
                                goto out;
 
-                       if (card->host->caps &
-                               (MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 |
-                                MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104 |
-                                MMC_CAP_UHS_DDR50)) {
+                       if (mmc_host_uhs(card->host)) {
                                if (data & SDIO_UHS_DDR50)
                                        card->sw_caps.sd3_bus_mode
                                                |= SD_MODE_UHS_DDR50;
@@ -478,8 +475,7 @@ static int sdio_set_bus_speed_mode(struct mmc_card *card)
         * If the host doesn't support any of the UHS-I modes, fallback on
         * default speed.
         */
-       if (!(card->host->caps & (MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 |
-           MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104 | MMC_CAP_UHS_DDR50)))
+       if (!mmc_host_uhs(card->host))
                return 0;
 
        bus_speed = SDIO_SPEED_SDR12;
@@ -645,11 +641,7 @@ static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr,
         * systems that claim 1.8v signalling in fact do not support
         * it.
         */
-       if ((ocr & R4_18V_PRESENT) &&
-               (host->caps &
-                       (MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 |
-                        MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104 |
-                        MMC_CAP_UHS_DDR50))) {
+       if ((ocr & R4_18V_PRESENT) && mmc_host_uhs(host)) {
                err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180,
                                true);
                if (err) {
@@ -1022,6 +1014,10 @@ static int mmc_sdio_power_restore(struct mmc_host *host)
                goto out;
        }
 
+       if (mmc_host_uhs(host))
+               /* to query card if 1.8V signalling is supported */
+               host->ocr |= R4_18V_PRESENT;
+
        ret = mmc_sdio_init_card(host, host->ocr, host->card,
                                mmc_card_keep_power(host));
        if (!ret && host->sdio_irqs)
@@ -1087,6 +1083,10 @@ int mmc_attach_sdio(struct mmc_host *host)
        /*
         * Detect and init the card.
         */
+       if (mmc_host_uhs(host))
+               /* to query card if 1.8V signalling is supported */
+               host->ocr |= R4_18V_PRESENT;
+
        err = mmc_sdio_init_card(host, host->ocr, NULL, 0);
        if (err) {
                if (err == -EAGAIN) {

diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 61a10c17aabd98df129c091bc82697b5faa0b09d..c89a1bb87fa5b4a655a76da23a87602bd4738a92 100644 (file)
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -434,6 +434,14 @@ static inline int mmc_boot_partition_access(struct mmc_host *host)
        return !(host->caps2 & MMC_CAP2_BOOTPART_NOACC);
 }
 
+static inline int mmc_host_uhs(struct mmc_host *host)
+{
+       return host->caps &
+               (MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 |
+                MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104 |
+                MMC_CAP_UHS_DDR50);
+}
+
 #ifdef CONFIG_MMC_CLKGATE
 void mmc_host_clk_hold(struct mmc_host *host);
 void mmc_host_clk_release(struct mmc_host *host);