[PATCH v5 05/14] mmc: sdhci: Disable 1.8v modes (HS200/HS400/UHS) if controller can't support 1.8v

From: Kishon Vijay Abraham I
Date: Fri Apr 27 2018 - 07:47:56 EST


The SDHCI controller in a SoC might support HS200/HS400 (indicated
using mmc-hs200-1_8v/mmc-hs400-1_8v dt property), but if the board is
modeled such that the IO lines are not connected to 1.8v then
HS200/HS400 cannot be supported. Disable HS200/HS400 if the board
does not have 1.8v connected to the IO lines. Also Disable DDR/UHS in 1.8v
if the IO lines are not connected to 1.8v.

Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
Acked-by: Tony Lindgren <tony@xxxxxxxxxxx>
---
drivers/mmc/host/sdhci.c | 10 ++++++++++
include/linux/mmc/host.h | 4 ++++
2 files changed, 14 insertions(+)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 2ededa7f43df..0f3cdca3e769 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -3672,6 +3672,16 @@ int sdhci_setup_host(struct sdhci_host *host)
if (host->quirks2 & SDHCI_QUIRK2_NO_1_8_V) {
host->caps1 &= ~(SDHCI_SUPPORT_SDR104 | SDHCI_SUPPORT_SDR50 |
SDHCI_SUPPORT_DDR50);
+ /*
+ * The SDHCI controller in a SoC might support HS200/HS400
+ * (indicated using mmc-hs200-1_8v/mmc-hs400-1_8v dt property),
+ * but if the board is modeled such that the IO lines are not
+ * connected to 1.8v then HS200/HS400 cannot be supported.
+ * Disable HS200/HS400 if the board does not have 1.8v connected
+ * to the IO lines. (Applicable for other modes in 1.8v)
+ */
+ mmc->caps2 &= ~(MMC_CAP2_HSX00_1_8V | MMC_CAP2_HS400_ES);
+ mmc->caps &= ~(MMC_CAP_1_8V_DDR | MMC_CAP_UHS);
}

/* Any UHS-I mode in caps implies SDR12 and SDR25 support. */
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 7c6eaf63f5ce..8f1859044db1 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -320,6 +320,9 @@ struct mmc_host {
#define MMC_CAP_UHS_SDR50 (1 << 18) /* Host supports UHS SDR50 mode */
#define MMC_CAP_UHS_SDR104 (1 << 19) /* Host supports UHS SDR104 mode */
#define MMC_CAP_UHS_DDR50 (1 << 20) /* Host supports UHS DDR50 mode */
+#define MMC_CAP_UHS (MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 | \
+ MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104 | \
+ MMC_CAP_UHS_DDR50)
/* (1 << 21) is free for reuse */
#define MMC_CAP_DRIVER_TYPE_A (1 << 23) /* Host supports Driver Type A */
#define MMC_CAP_DRIVER_TYPE_C (1 << 24) /* Host supports Driver Type C */
@@ -345,6 +348,7 @@ struct mmc_host {
#define MMC_CAP2_HS400_1_2V (1 << 16) /* Can support HS400 1.2V */
#define MMC_CAP2_HS400 (MMC_CAP2_HS400_1_8V | \
MMC_CAP2_HS400_1_2V)
+#define MMC_CAP2_HSX00_1_8V (MMC_CAP2_HS200_1_8V_SDR | MMC_CAP2_HS400_1_8V)
#define MMC_CAP2_HSX00_1_2V (MMC_CAP2_HS200_1_2V_SDR | MMC_CAP2_HS400_1_2V)
#define MMC_CAP2_SDIO_IRQ_NOTHREAD (1 << 17)
#define MMC_CAP2_NO_WRITE_PROTECT (1 << 18) /* No physical write protect pin, assume that card is always read-write */
--
2.17.0