ARM: rmobile: Implement PMIC reset on V2H Blanche

Add code to reset the board through PMIC, by writing the required
PMIC registers in the CPU reset handler.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
diff --git a/board/renesas/blanche/blanche.c b/board/renesas/blanche/blanche.c
index 7232370..471d80f 100644
--- a/board/renesas/blanche/blanche.c
+++ b/board/renesas/blanche/blanche.c
@@ -20,6 +20,7 @@
 #include <dm.h>
 #include <dm/platform_data/serial_sh.h>
 #include <env.h>
+#include <hang.h>
 #include <i2c.h>
 #include <linux/errno.h>
 #include <malloc.h>
@@ -355,4 +356,23 @@
 
 void reset_cpu(ulong addr)
 {
+	struct udevice *dev;
+	const u8 pmic_bus = 6;
+	const u8 pmic_addr = 0x58;
+	u8 data;
+	int ret;
+
+	ret = i2c_get_chip_for_busnum(pmic_bus, pmic_addr, 1, &dev);
+	if (ret)
+		hang();
+
+	ret = dm_i2c_read(dev, 0x13, &data, 1);
+	if (ret)
+		hang();
+
+	data |= BIT(1);
+
+	ret = dm_i2c_write(dev, 0x13, &data, 1);
+	if (ret)
+		hang();
 }