From: Jon Mayo <jmayo@nvidia.com>
Date: Thu, 7 Apr 2011 22:40:45 +0000 (-0700)
Subject: HACK: ARM: tegra: pinmux: drive strength just for DDC
X-Git-Tag: firefly_0821_release~9834^2~16
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=abcdca12e9273c0f3752ba7ca378b1ecb818f280;p=firefly-linux-kernel-4.4.55.git

HACK: ARM: tegra: pinmux: drive strength just for DDC

When programming DDC pingroup, use 20 for the pull up drive strength
offset instead of 12 (offset for pull down drive strength.)

Change-Id: I7e5c2d8c998556513f8b16d6510d6596763bcc87
Signed-off-by: Jon Mayo <jmayo@nvidia.com>
Signed-off-by: Erik Gilling <konkers@android.com>
---

diff --git a/arch/arm/mach-tegra/pinmux.c b/arch/arm/mach-tegra/pinmux.c
index f80d507671bc..3316c49db3cc 100644
--- a/arch/arm/mach-tegra/pinmux.c
+++ b/arch/arm/mach-tegra/pinmux.c
@@ -459,8 +459,22 @@ static int tegra_drive_pinmux_set_pull_up(enum tegra_drive_pingroup pg,
 	spin_lock_irqsave(&mux_lock, flags);
 
 	reg = pg_readl(drive_pingroups[pg].reg);
-	reg &= ~(0x1f << 12);
-	reg |= pull_up << 12;
+
+	/*
+	 * 12 is the wrong offset for pull_up drive strength.  This is
+	 * a hack for stingray to only use the correct offset for the
+	 * DDC lines to avoid changing drive strengths across the board
+	 * before cutting a release kernel.  This should be updated to
+	 * use the correct offset on the release is cut.
+	 */
+
+	if (pg == TEGRA_DRIVE_PINGROUP_DDC) {
+		reg &= ~(0x1f << 20);
+		reg |= pull_up << 20;
+	} else {
+		reg &= ~(0x1f << 12);
+		reg |= pull_up << 12;
+	}
 	pg_writel(reg, drive_pingroups[pg].reg);
 
 	spin_unlock_irqrestore(&mux_lock, flags);