[RFC PATCH 1/7] mmc: sdhci: add quirk for broken 3.0V support

[Vincent Yang]

This patch defines a quirk for platforms unable
to enable 3.0V support.
It is a preparation and will be used by Fujitsu
SDHCI controller f_sdh30 driver.

Signed-off-by: Vincent Yang <Vincent.Yang at tw.fujitsu.com>
---
 drivers/mmc/host/sdhci.c  | 3 +++
 include/linux/mmc/sdhci.h | 2 ++
 2 files changed, 5 insertions(+)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 47055f3..523075f 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -3069,6 +3069,9 @@ int sdhci_add_host(struct sdhci_host *host)
 	}
 #endif /* CONFIG_REGULATOR */
 
+	if (host->quirks2 & SDHCI_QUIRK2_NO_3_0_V)
+		caps[0] &= ~SDHCI_CAN_VDD_300;
+
 	/*
 	 * According to SD Host Controller spec v3.00, if the Host System
 	 * can afford more than 150mA, Host Driver should set XPC to 1. Also
diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h
index 08abe99..cac0958 100644
--- a/include/linux/mmc/sdhci.h
+++ b/include/linux/mmc/sdhci.h
@@ -98,6 +98,8 @@ struct sdhci_host {
 #define SDHCI_QUIRK2_BROKEN_HS200			(1<<6)
 /* Controller does not support DDR50 */
 #define SDHCI_QUIRK2_BROKEN_DDR50			(1<<7)
+/* The system physically doesn't support 3.0v, even if the host does */
+#define SDHCI_QUIRK2_NO_3_0_V				(1<<8)
 
 	int irq;		/* Device IRQ */
 	void __iomem *ioaddr;	/* Mapped address */
-- 
1.9.0