Re: [PATCH v9 2/6] clk: hisilicon: add CRG driver for hi3519 soc

diff --git a/drivers/clk/hisilicon/reset.c b/drivers/clk/hisilicon/reset.c
new file mode 100644
index 0000000..50e00e7
--- /dev/null
+++ b/drivers/clk/hisilicon/reset.c

@@ -0,0 +1,124 @@
+/*
+ * Hisilicon Reset Controller Driver
+ *
+ * Copyright (c) 2015-2016 HiSilicon Technologies Co., Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/reset-controller.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#define	HISI_RESET_BIT_MASK	0x1f
+#define	HISI_RESET_OFFSET_SHIFT	8
+#define	HISI_RESET_OFFSET_MASK	0xffff00
+
+struct hisi_reset_controller {
+	spinlock_t	lock;
+	void __iomem	*membase;
+	struct reset_controller_dev	rcdev;
+};
+
+
+#define to_hisi_reset_controller(rcdev)  \
+	container_of(rcdev, struct hisi_reset_controller, rcdev)
+
+static int hisi_reset_of_xlate(struct reset_controller_dev *rcdev,
+			const struct of_phandle_args *reset_spec)
+{
+	u32 offset;
+	u8 bit;
+
+	if (WARN_ON(reset_spec->args_count != rcdev->of_reset_n_cells))
+		return -EINVAL;

+	offset = (reset_spec->args[0] << HISI_RESET_OFFSET_SHIFT)
+		& HISI_RESET_OFFSET_MASK;
+	bit = reset_spec->args[1] & HISI_RESET_BIT_MASK;
+	return (offset | bit);
+}
+
+static int hisi_reset_assert(struct reset_controller_dev *rcdev,
+			      unsigned long id)
+{
+	struct hisi_reset_controller *rstc = to_hisi_reset_controller(rcdev);
+	unsigned long flags;
+	u32 offset, reg;
+	u8 bit;
+
+	offset = (id & HISI_RESET_OFFSET_MASK) >> HISI_RESET_OFFSET_SHIFT;
+	bit = id & HISI_RESET_BIT_MASK;
+
+	spin_lock_irqsave(&rstc->lock, flags);
+
+	reg = readl(rstc->membase + offset);
+	writel(reg | BIT(bit), rstc->membase + offset);
+
+	spin_unlock_irqrestore(&rstc->lock, flags);
+
+	return 0;
+}
+
+static int hisi_reset_deassert(struct reset_controller_dev *rcdev,
+				unsigned long id)
+{
+	struct hisi_reset_controller *rstc = to_hisi_reset_controller(rcdev);
+	unsigned long flags;
+	u32 offset, reg;
+	u8 bit;
+
+	offset = (id & HISI_RESET_OFFSET_MASK) >> HISI_RESET_OFFSET_SHIFT;
+	bit = id & HISI_RESET_BIT_MASK;
+
+	spin_lock_irqsave(&rstc->lock, flags);
+
+	reg = readl(rstc->membase + offset);
+	writel(reg & ~BIT(bit), rstc->membase + offset);
+
+	spin_unlock_irqrestore(&rstc->lock, flags);
+
+	return 0;
+}
+
+static struct reset_control_ops hisi_reset_ops = {
+	.assert		= hisi_reset_assert,
+	.deassert	= hisi_reset_deassert,
+};