reset: hi6220: Reset driver for hisilicon hi6220 SoC

Add reset driver for hi6220-hikey board,this driver supply deassert
of IP on hi6220 SoC.
Signed-off-by: Chen Feng <puck.chen@hisilicon.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

drivers/reset/Kconfig

@@ -13,3 +13,4 @@ menuconfig RESET_CONTROLLER
 	  If unsure, say no.
 
 source "drivers/reset/sti/Kconfig"
+source "drivers/reset/hisilicon/Kconfig"

drivers/reset/Makefile

@@ -4,5 +4,6 @@ obj-$(CONFIG_ARCH_SOCFPGA) += reset-socfpga.o
 obj-$(CONFIG_ARCH_BERLIN) += reset-berlin.o
 obj-$(CONFIG_ARCH_SUNXI) += reset-sunxi.o
 obj-$(CONFIG_ARCH_STI) += sti/
+obj-$(CONFIG_ARCH_HISI) += hisilicon/
 obj-$(CONFIG_ARCH_ZYNQ) += reset-zynq.o
 obj-$(CONFIG_ATH79) += reset-ath79.o

drivers/reset/hisilicon/Kconfig

+config COMMON_RESET_HI6220
+	tristate "Hi6220 Reset Driver"
+	depends on (ARCH_HISI && RESET_CONTROLLER)
+	help
+	  Build the Hisilicon Hi6220 reset driver.

drivers/reset/hisilicon/Makefile

+obj-$(CONFIG_COMMON_RESET_HI6220) += hi6220_reset.o

drivers/reset/hisilicon/hi6220_reset.c

+/*
+ * Hisilicon Hi6220 reset controller driver
+ *
+ * Copyright (c) 2015 Hisilicon Limited.
+ *
+ * Author: Feng Chen <puck.chen@hisilicon.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.
+ */
+
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/bitops.h>
+#include <linux/of.h>
+#include <linux/reset-controller.h>
+#include <linux/reset.h>
+#include <linux/platform_device.h>
+
+#define ASSERT_OFFSET            0x300
+#define DEASSERT_OFFSET          0x304
+#define MAX_INDEX                0x509
+
+#define to_reset_data(x) container_of(x, struct hi6220_reset_data, rc_dev)
+
+struct hi6220_reset_data {
+	void __iomem			*assert_base;
+	void __iomem			*deassert_base;
+	struct reset_controller_dev	rc_dev;
+};
+
+static int hi6220_reset_assert(struct reset_controller_dev *rc_dev,
+			       unsigned long idx)
+{
+	struct hi6220_reset_data *data = to_reset_data(rc_dev);
+
+	int bank = idx >> 8;
+	int offset = idx & 0xff;
+
+	writel(BIT(offset), data->assert_base + (bank * 0x10));
+
+	return 0;
+}
+
+static int hi6220_reset_deassert(struct reset_controller_dev *rc_dev,
+				 unsigned long idx)
+{
+	struct hi6220_reset_data *data = to_reset_data(rc_dev);
+
+	int bank = idx >> 8;
+	int offset = idx & 0xff;
+
+	writel(BIT(offset), data->deassert_base + (bank * 0x10));
+
+	return 0;
+}
+
+static struct reset_control_ops hi6220_reset_ops = {
+	.assert = hi6220_reset_assert,
+	.deassert = hi6220_reset_deassert,
+};
+
+static int hi6220_reset_probe(struct platform_device *pdev)
+{
+	struct hi6220_reset_data *data;
+	struct resource *res;
+	void __iomem *src_base;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	src_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(src_base))
+		return PTR_ERR(src_base);
+
+	data->assert_base = src_base + ASSERT_OFFSET;
+	data->deassert_base = src_base + DEASSERT_OFFSET;
+	data->rc_dev.nr_resets = MAX_INDEX;
+	data->rc_dev.ops = &hi6220_reset_ops;
+	data->rc_dev.of_node = pdev->dev.of_node;
+
+	reset_controller_register(&data->rc_dev);
+
+	return 0;
+}
+
+static const struct of_device_id hi6220_reset_match[] = {
+	{ .compatible = "hisilicon,hi6220-sysctrl" },
+	{ },
+};
+
+static struct platform_driver hi6220_reset_driver = {
+	.probe = hi6220_reset_probe,
+	.driver = {
+		.name = "reset-hi6220",
+		.of_match_table = hi6220_reset_match,
+	},
+};
+
+static int __init hi6220_reset_init(void)
+{
+	return platform_driver_register(&hi6220_reset_driver);
+}
+
+postcore_initcall(hi6220_reset_init);