[PATCH 1/3] reset: hisilicon: add reset controller driver for hisilicon SOCs

From: Jiancheng Xue
Date: Sat Apr 23 2016 - 03:51:57 EST


In most of hisilicon SOCs, reset controller and clock provider are
combined together as a block named CRG (Clock and Reset Generator).
This patch mainly implements the reset function.

Signed-off-by: Jiancheng Xue <xuejiancheng@xxxxxxxxxxxxx>
Acked-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
---
drivers/clk/hisilicon/Kconfig | 7 +++
drivers/clk/hisilicon/Makefile | 1 +
drivers/clk/hisilicon/reset.c | 134 +++++++++++++++++++++++++++++++++++++++++
drivers/clk/hisilicon/reset.h | 36 +++++++++++
4 files changed, 178 insertions(+)
create mode 100644 drivers/clk/hisilicon/reset.c
create mode 100644 drivers/clk/hisilicon/reset.h

diff --git a/drivers/clk/hisilicon/Kconfig b/drivers/clk/hisilicon/Kconfig
index e434854..3cd349c 100644
--- a/drivers/clk/hisilicon/Kconfig
+++ b/drivers/clk/hisilicon/Kconfig
@@ -5,6 +5,13 @@ config COMMON_CLK_HI6220
help
Build the Hisilicon Hi6220 clock driver based on the common clock framework.

+config RESET_HISI
+ bool "HiSilicon Reset Controller Driver"
+ depends on ARCH_HISI || COMPILE_TEST
+ select RESET_CONTROLLER
+ help
+ Build reset controller driver for HiSilicon device chipsets.
+
config STUB_CLK_HI6220
bool "Hi6220 Stub Clock Driver"
depends on COMMON_CLK_HI6220 && MAILBOX
diff --git a/drivers/clk/hisilicon/Makefile b/drivers/clk/hisilicon/Makefile
index 74dba31..c037753 100644
--- a/drivers/clk/hisilicon/Makefile
+++ b/drivers/clk/hisilicon/Makefile
@@ -8,4 +8,5 @@ obj-$(CONFIG_ARCH_HI3xxx) += clk-hi3620.o
obj-$(CONFIG_ARCH_HIP04) += clk-hip04.o
obj-$(CONFIG_ARCH_HIX5HD2) += clk-hix5hd2.o
obj-$(CONFIG_COMMON_CLK_HI6220) += clk-hi6220.o
+obj-$(CONFIG_RESET_HISI) += reset.o
obj-$(CONFIG_STUB_CLK_HI6220) += clk-hi6220-stub.o
diff --git a/drivers/clk/hisilicon/reset.c b/drivers/clk/hisilicon/reset.c
new file mode 100644
index 0000000..6aa49c2
--- /dev/null
+++ b/drivers/clk/hisilicon/reset.c
@@ -0,0 +1,134 @@
+/*
+ * 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>
+#include "reset.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;
+
+ 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 const struct reset_control_ops hisi_reset_ops = {
+ .assert = hisi_reset_assert,
+ .deassert = hisi_reset_deassert,
+};
+
+struct hisi_reset_controller *hisi_reset_init(struct device_node *np)
+{
+ struct hisi_reset_controller *rstc;
+
+ rstc = kzalloc(sizeof(*rstc), GFP_KERNEL);
+ if (!rstc)
+ return NULL;
+
+ rstc->membase = of_iomap(np, 0);
+ if (!rstc->membase) {
+ kfree(rstc);
+ return NULL;
+ }
+
+ spin_lock_init(&rstc->lock);
+
+ rstc->rcdev.owner = THIS_MODULE;
+ rstc->rcdev.ops = &hisi_reset_ops;
+ rstc->rcdev.of_node = np;
+ rstc->rcdev.of_reset_n_cells = 2;
+ rstc->rcdev.of_xlate = hisi_reset_of_xlate;
+ reset_controller_register(&rstc->rcdev);
+
+ return rstc;
+}
+EXPORT_SYMBOL_GPL(hisi_reset_init);
+
+void hisi_reset_exit(struct hisi_reset_controller *rstc)
+{
+ reset_controller_unregister(&rstc->rcdev);
+ iounmap(rstc->membase);
+ kfree(rstc);
+}
+EXPORT_SYMBOL_GPL(hisi_reset_exit);
diff --git a/drivers/clk/hisilicon/reset.h b/drivers/clk/hisilicon/reset.h
new file mode 100644
index 0000000..677d773
--- /dev/null
+++ b/drivers/clk/hisilicon/reset.h
@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2015 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/>.
+ */
+
+#ifndef __HISI_RESET_H
+#define __HISI_RESET_H
+
+struct device_node;
+struct hisi_reset_controller;
+
+#ifdef CONFIG_RESET_CONTROLLER
+struct hisi_reset_controller *hisi_reset_init(struct device_node *np);
+void hisi_reset_exit(struct hisi_reset_controller *rstc);
+#else
+static inline hisi_reset_controller *hisi_reset_init(struct device_node *np)
+{
+ return 0;
+}
+static inline void hisi_reset_exit(struct hisi_reset_controller *rstc)
+{}
+#endif
+
+#endif /* __HISI_RESET_H */
--
1.9.1