ARM: Layerscape: PPA: Disable CAAM JR used by secure firmware

JR3 is used by the secure firmware. We have to remove the node from
the Linux device tree to prevent Linux from using it.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 19 insertions, 0 deletions

diff --git a/arch/arm/mach-layerscape/ppa.c b/arch/arm/mach-layerscape/ppa.c
index 6070451020..c5eba35b33 100644
--- a/arch/arm/mach-layerscape/ppa.c
+++ b/arch/arm/mach-layerscape/ppa.c
@@ -18,14 +18,33 @@
 int ppa_entry(const void *, u32 *, u32 *);
 void dma_flush_range(void *ptr, size_t size);
 
+#define SEC_JR3_OFFSET                     0x40000
+
 static int of_psci_do_fixup(struct device_node *root, void *unused)
 {
 	unsigned long psci_version;
+	struct device_node *np;
 	struct arm_smccc_res res = {};
 
 	arm_smccc_smc(ARM_PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0, 0, 0, 0, 0, &res);
 	psci_version = res.a0;
 
+	for_each_compatible_node_from(np, root, NULL, "fsl,sec-v4.0-job-ring") {
+		const void *reg;
+		int na = of_n_addr_cells(np);
+		u64 offset;
+
+		reg = of_get_property(np, "reg", NULL);
+		if (!reg)
+			continue;
+
+		offset = of_read_number(reg, na);
+		if (offset != SEC_JR3_OFFSET)
+			continue;
+
+		of_delete_node(np);
+	}
+
 	return of_psci_fixup(root, psci_version);
 }