[PATCH v2 1/3] ARM: mediatek: Add Reset Controller for MediaTek SoC

[Flora Fu]

Add a driver in reset controller.

Signed-off-by: Flora Fu <flora.fu at mediatek.com>
---
 drivers/reset/Makefile    |   1 +
 drivers/reset/reset-mtk.c | 131 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 132 insertions(+)
 create mode 100644 drivers/reset/reset-mtk.c

diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index 60fed3d..adcebdf 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -2,3 +2,4 @@ obj-$(CONFIG_RESET_CONTROLLER) += core.o
 obj-$(CONFIG_ARCH_SOCFPGA) += reset-socfpga.o
 obj-$(CONFIG_ARCH_SUNXI) += reset-sunxi.o
 obj-$(CONFIG_ARCH_STI) += sti/
+obj-$(CONFIG_ARCH_MEDIATEK) += reset-mtk.o
diff --git a/drivers/reset/reset-mtk.c b/drivers/reset/reset-mtk.c
new file mode 100644
index 0000000..7d792ec
--- /dev/null
+++ b/drivers/reset/reset-mtk.c
@@ -0,0 +1,131 @@
+/*
+ * Copyright (c) 2014 MediaTek Inc.
+ * Author: Flora.Fu <flora.fu at mediatek.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/reset-controller.h>
+
+struct mtk_reset_data {
+	struct regmap *regmap;
+	u32 resetbase;
+	u32 num_regs;
+	struct reset_controller_dev rcdev;
+};
+
+static int mtk_reset_assert(struct reset_controller_dev *rcdev,
+			      unsigned long id)
+{
+	struct regmap *regmap;
+	u32 addr;
+	u32 mask;
+	struct mtk_reset_data *data = container_of(rcdev,
+						     struct mtk_reset_data,
+						     rcdev);
+	regmap = data->regmap;
+	addr = data->resetbase + ((id / 32) << 2);
+	mask = BIT(id % 32);
+
+	return regmap_update_bits(regmap, addr, mask, mask);
+}
+
+static int mtk_reset_deassert(struct reset_controller_dev *rcdev,
+				unsigned long id)
+{
+	struct regmap *regmap;
+	u32 addr;
+	u32 mask;
+	struct mtk_reset_data *data = container_of(rcdev,
+						     struct mtk_reset_data,
+						     rcdev);
+
+	regmap = data->regmap;
+	addr = data->resetbase + ((id / 32) << 2);
+	mask = BIT(id % 32);
+
+	return regmap_update_bits(regmap, addr, mask, ~mask);
+}
+
+static struct reset_control_ops mtk_reset_ops = {
+	.assert = mtk_reset_assert,
+	.deassert = mtk_reset_deassert,
+};
+
+static int mtk_reset_probe(struct platform_device *pdev)
+{
+	struct mtk_reset_data *data;
+	struct device_node *np = pdev->dev.of_node;
+	struct device_node *syscon_np;
+	u32 reg[2];
+	int ret;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	syscon_np = of_get_parent(np);
+	data->regmap = syscon_node_to_regmap(syscon_np);
+	of_node_put(syscon_np);
+	if (IS_ERR(data->regmap)) {
+		dev_err(&pdev->dev, "couldn't get syscon-reset regmap\n");
+		return PTR_ERR(data->regmap);
+	}
+	ret = of_property_read_u32_array(np, "reg", reg, 2);
+	if (ret) {
+		dev_err(&pdev->dev, "couldn't read reset base from syscon!\n");
+		return -EINVAL;
+	}
+
+	data->resetbase = reg[0];
+	data->num_regs = reg[1] >> 2;
+	data->rcdev.owner = THIS_MODULE;
+	data->rcdev.nr_resets = data->num_regs * 32;
+	data->rcdev.ops = &mtk_reset_ops;
+	data->rcdev.of_node = pdev->dev.of_node;
+
+	return reset_controller_register(&data->rcdev);
+}
+
+static int mtk_reset_remove(struct platform_device *pdev)
+{
+	struct mtk_reset_data *data = platform_get_drvdata(pdev);
+
+	reset_controller_unregister(&data->rcdev);
+
+	return 0;
+}
+
+static const struct of_device_id mtk_reset_dt_ids[] = {
+	{ .compatible = "mediatek,reset", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, mtk_reset_dt_ids);
+
+static struct platform_driver mtk_reset_driver = {
+	.probe = mtk_reset_probe,
+	.remove = mtk_reset_remove,
+	.driver = {
+		.name = "mtk-reset",
+		.owner = THIS_MODULE,
+		.of_match_table = mtk_reset_dt_ids,
+	},
+};
+
+module_platform_driver(mtk_reset_driver);
+
+MODULE_AUTHOR("Flora Fu <flora.fu at mediatek.com>");
+MODULE_DESCRIPTION("MediaTek SoC Generic Reset Controller");
+MODULE_LICENSE("GPL");
-- 
1.8.1.1.dirty