stm32mp: syscon: manage clock when present in device tree

Enable the clocks during syscon probe when they are present in device tree.

This patch avoids a freeze when the SYSCFG clock is not enabled by
TF-A / OP-TEE.
Signed-off-by: NPatrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: NPatrice Chotard <patrice.chotard@foss.st.com>

arch/arm/mach-stm32mp/syscon.c

@@ -4,6 +4,7 @@
  */
 
 #include <common.h>
+#include <clk.h>
 #include <dm.h>
 #include <syscon.h>
 #include <asm/arch/stm32.h>
@@ -14,9 +15,22 @@ static const struct udevice_id stm32mp_syscon_ids[] = {
 	{ }
 };
 
+static int stm32mp_syscon_probe(struct udevice *dev)
+{
+	struct clk_bulk clk_bulk;
+	int ret;
+
+	ret = clk_get_bulk(dev, &clk_bulk);
+	if (!ret)
+		clk_enable_bulk(&clk_bulk);
+
+	return 0;
+}
+
 U_BOOT_DRIVER(syscon_stm32mp) = {
 	.name = "stmp32mp_syscon",
 	.id = UCLASS_SYSCON,
 	.of_match = stm32mp_syscon_ids,
 	.bind = dm_scan_fdt_dev,
+	.probe = stm32mp_syscon_probe,
 };