[PATCH v2 2/2] x86: edison: Don't take SD card detect pin into consideration

[Andy Shevchenko]

There are two PCB designs in the wild which use the opposite
signaling for SD card detection. This makes U-Boot working
in one case and failing in the other. Quirk this out by
disconnecting SD card detection pin from the PCB by switching
it to mode 3. In the disconnected state the read value is always
the same and inverted to what we are expecting in the code.

BugLink: https://github.com/edison-fw/meta-intel-edison/issues/136
Signed-off-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
---
v2: added tag, updated commit message and comments in DTS (Bin)
 arch/x86/dts/edison.dts | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/arch/x86/dts/edison.dts b/arch/x86/dts/edison.dts
index 2c8cf6c07102..b3658b8c3049 100644
--- a/arch/x86/dts/edison.dts
+++ b/arch/x86/dts/edison.dts
@@ -94,6 +94,12 @@
 	sdcard: mmc at ff3fa000 {
 		compatible = "intel,sdhci-tangier";
 		reg = <0xff3fa000 0x1000>;
+		/*
+		 * In the disconnected state of the SD Card Detection pin
+		 * the read value is always the same and inverted to what
+		 * we are expecting in the code.
+		 */
+		cd-inverted;
 	};
 
 	pmu: power at ff00b000 {
@@ -131,6 +137,17 @@
 		compatible = "intel,pinctrl-tangier";
 		reg = <0xff0c0000 0x8000>;
 
+		/*
+		 * Disconnect SD card detection pin, so it won't affect
+		 * the reality on two different PCB designs where it's
+		 * using the opposite signaling: Edison/Arduino uses
+		 * Active Low, while SparkFun went with Active High.
+		 */
+		sd_cd at 0 {
+			pad-offset = <37>;
+			mode-func = <3>;
+		};
+
 		/*
 		 * Initial configuration came from the firmware.
 		 * Which quite likely has been used in the phones, where I2C #8,
-- 
2.33.0