imx8m: fixup thermal trips

Fixup thermal trips in Linux device tree according to SoC thermal
grade.

Signed-off-by: Andrejs Cainikovs <andrejs.cainikovs@toradex.com>
Reviewed-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Tested-by: Adam Ford <aford173@gmail.com>
diff --git a/arch/arm/mach-imx/imx8m/soc.c b/arch/arm/mach-imx/imx8m/soc.c
index 5933535..e4e5607 100644
--- a/arch/arm/mach-imx/imx8m/soc.c
+++ b/arch/arm/mach-imx/imx8m/soc.c
@@ -1203,6 +1203,48 @@
 	return 0;
 }
 
+static int fixup_thermal_trips(void *blob, const char *name)
+{
+	int minc, maxc;
+	int node, trip;
+
+	node = fdt_path_offset(blob, "/thermal-zones");
+	if (node < 0)
+		return node;
+
+	node = fdt_subnode_offset(blob, node, name);
+	if (node < 0)
+		return node;
+
+	node = fdt_subnode_offset(blob, node, "trips");
+	if (node < 0)
+		return node;
+
+	get_cpu_temp_grade(&minc, &maxc);
+
+	fdt_for_each_subnode(trip, blob, node) {
+		const char *type;
+		int temp, ret;
+
+		type = fdt_getprop(blob, trip, "type", NULL);
+		if (!type)
+			continue;
+
+		temp = 0;
+		if (!strcmp(type, "critical"))
+			temp = 1000 * maxc;
+		else if (!strcmp(type, "passive"))
+			temp = 1000 * (maxc - 10);
+		if (temp) {
+			ret = fdt_setprop_u32(blob, trip, "temperature", temp);
+			if (ret)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+
 int ft_system_setup(void *blob, struct bd_info *bd)
 {
 #ifdef CONFIG_IMX8MQ
@@ -1345,6 +1387,13 @@
 #endif
 
 	cleanup_nodes_for_efi(blob);
+
+	if (fixup_thermal_trips(blob, "cpu-thermal"))
+		printf("Failed to update cpu-thermal trip(s)");
+	if (IS_ENABLED(CONFIG_IMX8MP) &&
+	    fixup_thermal_trips(blob, "soc-thermal"))
+		printf("Failed to update soc-thermal trip(s)");
+
 	return 0;
 }
 #endif