reset: MedaiTek: add reset controller driver for MediaTek SoCs

This patch adds reset controller driver for MediaTek SoCs.

Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>

arch/arm/include/asm/arch-mediatek/reset.h

@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2018 MediaTek Inc.
+ */
+
+#ifndef __MEDIATEK_RESET_H
+#define __MEDIATEK_RESET_H
+
+#include <dm.h>
+
+int mediatek_reset_bind(struct udevice *pdev, u32 regofs, u32 num_regs);
+
+#endif	/* __MEDIATEK_RESET_H */

drivers/reset/Kconfig

@@ -106,4 +106,11 @@ config RESET_SOCFPGA
 	help
 	  Support for reset controller on SoCFPGA platform.
 
+config RESET_MEDIATEK
+	bool "Reset controller driver for MediaTek SoCs"
+	depends on DM_RESET && ARCH_MEDIATEK && CLK
+	default y
+	help
+	  Support for reset controller on MediaTek SoCs.
+
 endmenu

drivers/reset/Makefile

@@ -17,3 +17,4 @@ obj-$(CONFIG_AST2500_RESET) += ast2500-reset.o
 obj-$(CONFIG_RESET_ROCKCHIP) += reset-rockchip.o
 obj-$(CONFIG_RESET_MESON) += reset-meson.o
 obj-$(CONFIG_RESET_SOCFPGA) += reset-socfpga.o
+obj-$(CONFIG_RESET_MEDIATEK) += reset-mediatek.o

drivers/reset/reset-mediatek.c

@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2018 MediaTek Inc.
+ *
+ * Author: Ryder Lee <ryder.lee@mediatek.com>
+ *	   Weijie Gao <weijie.gao@mediatek.com>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dm/lists.h>
+#include <regmap.h>
+#include <reset-uclass.h>
+#include <syscon.h>
+
+struct mediatek_reset_priv {
+	struct regmap *regmap;
+	u32 regofs;
+	u32 nr_resets;
+};
+
+static int mediatek_reset_request(struct reset_ctl *reset_ctl)
+{
+	return 0;
+}
+
+static int mediatek_reset_free(struct reset_ctl *reset_ctl)
+{
+	return 0;
+}
+
+static int mediatek_reset_assert(struct reset_ctl *reset_ctl)
+{
+	struct mediatek_reset_priv *priv = dev_get_priv(reset_ctl->dev);
+	int id = reset_ctl->id;
+
+	if (id >= priv->nr_resets)
+		return -EINVAL;
+
+	return regmap_update_bits(priv->regmap,
+		priv->regofs + ((id / 32) << 2), BIT(id % 32), BIT(id % 32));
+}
+
+static int mediatek_reset_deassert(struct reset_ctl *reset_ctl)
+{
+	struct mediatek_reset_priv *priv = dev_get_priv(reset_ctl->dev);
+	int id = reset_ctl->id;
+
+	if (id >= priv->nr_resets)
+		return -EINVAL;
+
+	return regmap_update_bits(priv->regmap,
+		priv->regofs + ((id / 32) << 2), BIT(id % 32), 0);
+}
+
+struct reset_ops mediatek_reset_ops = {
+	.request = mediatek_reset_request,
+	.free = mediatek_reset_free,
+	.rst_assert = mediatek_reset_assert,
+	.rst_deassert = mediatek_reset_deassert,
+};
+
+static int mediatek_reset_probe(struct udevice *dev)
+{
+	struct mediatek_reset_priv *priv = dev_get_priv(dev);
+
+	if (!priv->regofs && !priv->nr_resets)
+		return -EINVAL;
+
+	priv->regmap = syscon_node_to_regmap(dev_ofnode(dev));
+	if (IS_ERR(priv->regmap))
+		return PTR_ERR(priv->regmap);
+
+	return 0;
+}
+
+int mediatek_reset_bind(struct udevice *pdev, u32 regofs, u32 num_regs)
+{
+	struct udevice *rst_dev;
+	struct mediatek_reset_priv *priv;
+	int ret;
+
+	ret = device_bind_driver_to_node(pdev, "mediatek_reset", "reset",
+					 dev_ofnode(pdev), &rst_dev);
+	if (ret)
+		return ret;
+
+	priv = malloc(sizeof(struct mediatek_reset_priv));
+	priv->regofs = regofs;
+	priv->nr_resets = num_regs * 32;
+	rst_dev->priv = priv;
+
+	return 0;
+}
+
+U_BOOT_DRIVER(mediatek_reset) = {
+	.name = "mediatek_reset",
+	.id = UCLASS_RESET,
+	.probe = mediatek_reset_probe,
+	.ops = &mediatek_reset_ops,
+	.priv_auto_alloc_size = sizeof(struct mediatek_reset_priv),
+};

include/dt-bindings/reset/mtk-reset.h

@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2018 MediaTek Inc.
+ */
+
+#ifndef _DT_BINDINGS_MTK_RESET_H_
+#define _DT_BINDINGS_MTK_RESET_H_
+
+/* ETHSYS */
+#define ETHSYS_PPE_RST			31
+#define ETHSYS_EPHY_RST			24
+#define ETHSYS_GMAC_RST			23
+#define ETHSYS_ESW_RST			16
+#define ETHSYS_FE_RST			6
+#define ETHSYS_MCM_RST			2
+#define ETHSYS_SYS_RST			0
+
+#endif /* _DT_BINDINGS_MTK_RESET_H_ */