rockchip: rk3036: Add Soc reset driver

We can reset the Soc using some CRU (clock/reset unit) register.
Add support for this.

Signed-off-by: Lin Huang <hl@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>

arch/arm/mach-rockchip/rk3036/Makefile

+#
+# (C) Copyright 2015 Rockchip Electronics Co., Ltd
+#
+# SPDX-License-Identifier:     GPL-2.0+
+#
+
+ifndef CONFIG_SPL_BUILD
+obj-y += reset_rk3036.o
+endif
+

arch/arm/mach-rockchip/rk3036/reset_rk3036.c

+/*
+ * (C) Copyright 2015 Rockchip Electronics Co., Ltd
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <reset.h>
+#include <asm/io.h>
+#include <asm/arch/clock.h>
+#include <asm/arch/cru_rk3036.h>
+#include <asm/arch/hardware.h>
+#include <linux/err.h>
+
+int rk3036_reset_request(struct udevice *dev, enum reset_t type)
+{
+	struct rk3036_cru *cru = rockchip_get_cru();
+
+	if (IS_ERR(cru))
+		return PTR_ERR(cru);
+	switch (type) {
+	case RESET_WARM:
+		writel(0xeca8, &cru->cru_glb_srst_snd_value);
+		break;
+	case RESET_COLD:
+		writel(0xfdb9, &cru->cru_glb_srst_fst_value);
+		break;
+	default:
+		return -EPROTONOSUPPORT;
+	}
+
+	return -EINPROGRESS;
+}
+
+static struct reset_ops rk3036_reset = {
+	.request	= rk3036_reset_request,
+};
+
+U_BOOT_DRIVER(reset_rk3036) = {
+	.name	= "rk3036_reset",
+	.id	= UCLASS_RESET,
+	.ops	= &rk3036_reset,
+};