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>

2 files changed, 19 insertions, 11 deletions

diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index 55a49d066dbd..c7b7b923c433 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -162,10 +162,7 @@ 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;
@@ -483,8 +480,7 @@ 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;
@@ -650,11 +646,7 @@ 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) {
@@ -1041,6 +1033,10 @@ 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)
@@ -1106,6 +1102,10 @@ 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 6830b56dce09..7c5be5810a84 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -470,6 +470,14 @@ 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);