Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/arm/mach-omap2/omap-iommu.c b/arch/arm/mach-omap2/omap-iommu.c
new file mode 100644
index 0000000..f1a6ece
--- /dev/null
+++ b/arch/arm/mach-omap2/omap-iommu.c
@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * OMAP IOMMU quirks for various TI SoCs
+ *
+ * Copyright (C) 2015-2019 Texas Instruments Incorporated - http://www.ti.com/
+ *      Suman Anna <s-anna@ti.com>
+ */
+
+#include <linux/platform_device.h>
+#include <linux/err.h>
+
+#include "omap_hwmod.h"
+#include "omap_device.h"
+#include "powerdomain.h"
+
+int omap_iommu_set_pwrdm_constraint(struct platform_device *pdev, bool request,
+				    u8 *pwrst)
+{
+	struct powerdomain *pwrdm;
+	struct omap_device *od;
+	u8 next_pwrst;
+
+	od = to_omap_device(pdev);
+	if (!od)
+		return -ENODEV;
+
+	if (od->hwmods_cnt != 1)
+		return -EINVAL;
+
+	pwrdm = omap_hwmod_get_pwrdm(od->hwmods[0]);
+	if (!pwrdm)
+		return -EINVAL;
+
+	if (request)
+		*pwrst = pwrdm_read_next_pwrst(pwrdm);
+
+	if (*pwrst > PWRDM_POWER_RET)
+		return 0;
+
+	next_pwrst = request ? PWRDM_POWER_ON : *pwrst;
+
+	return pwrdm_set_next_pwrst(pwrdm, next_pwrst);
+}