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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/Documentation/devicetree/bindings/mmc/mmc-pwrseq-emmc.txt
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
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+* The simple eMMC hardware reset provider
+
+The purpose of this driver is to perform standard eMMC hw reset
+procedure, as descibed by Jedec 4.4 specification. This procedure is
+performed just after MMC core enabled power to the given mmc host (to
+fix possible issues if bootloader has left eMMC card in initialized or
+unknown state), and before performing complete system reboot (also in
+case of emergency reboot call). The latter is needed on boards, which
+doesn't have hardware reset logic connected to emmc card and (limited or
+broken) ROM bootloaders are unable to read second stage from the emmc
+card if the card is left in unknown or already initialized state.
+
+Required properties:
+- compatible : contains "mmc-pwrseq-emmc".
+- reset-gpios : contains a GPIO specifier. The reset GPIO is asserted
+ and then deasserted to perform eMMC card reset. To perform
+ reset procedure as described in Jedec 4.4 specification, the
+ gpio line should be defined as GPIO_ACTIVE_LOW.
+
+Example:
+
+ sdhci0_pwrseq {
+ compatible = "mmc-pwrseq-emmc";
+ reset-gpios = <&gpio1 12 GPIO_ACTIVE_LOW>;
+ }