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

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Date:   Fri, 27 Apr 2018 17:17:14 +0530
From:   Kishon Vijay Abraham I <kishon@...com>
To:     Ulf Hansson <ulf.hansson@...aro.org>,
        Adrian Hunter <adrian.hunter@...el.com>
CC:     Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        <linux-mmc@...r.kernel.org>, <devicetree@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>, <linux-omap@...r.kernel.org>,
        <kishon@...com>
Subject: [PATCH v5 05/14] mmc: sdhci: Disable 1.8v modes (HS200/HS400/UHS) if controller can't support 1.8v

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@...com>
Acked-by: Tony Lindgren <tony@...mide.com>
---
 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