2 files changed, 176 insertions, 0 deletions

diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index 1e2d83f2b995..cc29832c9638 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -1 +1,2 @@
 obj-$(CONFIG_RESET_CONTROLLER) += core.o
+obj-$(CONFIG_ARCH_SUNXI) += reset-sunxi.o
diff --git a/drivers/reset/reset-sunxi.c b/drivers/reset/reset-sunxi.c
new file mode 100644
index 000000000000..695bd3496eba
--- /dev/null
+++ b/drivers/reset/reset-sunxi.c
@@ -0,0 +1,175 @@
+/*
+ * Allwinner SoCs Reset Controller driver
+ *
+ * Copyright 2013 Maxime Ripard
+ *
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ *
+ * 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.
+ */
+
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+struct sunxi_reset_data {
+        spinlock_t                      lock;
+        void __iomem                    *membase;
+        struct reset_controller_dev     rcdev;
+};
+
+static int sunxi_reset_assert(struct reset_controller_dev *rcdev,
+                              unsigned long id)
+{
+        struct sunxi_reset_data *data = container_of(rcdev,
+                                                     struct sunxi_reset_data,
+                                                     rcdev);
+        int bank = id / BITS_PER_LONG;
+        int offset = id % BITS_PER_LONG;
+        unsigned long flags;
+        u32 reg;
+
+        spin_lock_irqsave(&data->lock, flags);
+
+        reg = readl(data->membase + (bank * 4));
+        writel(reg & ~BIT(offset), data->membase + (bank * 4));
+
+        spin_unlock_irqrestore(&data->lock, flags);
+
+        return 0;
+}
+
+static int sunxi_reset_deassert(struct reset_controller_dev *rcdev,
+                                unsigned long id)
+{
+        struct sunxi_reset_data *data = container_of(rcdev,
+                                                     struct sunxi_reset_data,
+                                                     rcdev);
+        int bank = id / BITS_PER_LONG;
+        int offset = id % BITS_PER_LONG;
+        unsigned long flags;
+        u32 reg;
+
+        spin_lock_irqsave(&data->lock, flags);
+
+        reg = readl(data->membase + (bank * 4));
+        writel(reg | BIT(offset), data->membase + (bank * 4));
+
+        spin_unlock_irqrestore(&data->lock, flags);
+
+        return 0;
+}
+
+static struct reset_control_ops sunxi_reset_ops = {
+        .assert         = sunxi_reset_assert,
+        .deassert       = sunxi_reset_deassert,
+};
+
+static int sunxi_reset_init(struct device_node *np)
+{
+        struct sunxi_reset_data *data;
+        struct resource res;
+        resource_size_t size;
+        int ret;
+
+        data = kzalloc(sizeof(*data), GFP_KERNEL);
+        if (!data)
+                return -ENOMEM;
+
+        ret = of_address_to_resource(np, 0, &res);
+        if (ret)
+                goto err_alloc;
+
+        size = resource_size(&res);
+        if (!request_mem_region(res.start, size, np->name)) {
+                ret = -EBUSY;
+                goto err_alloc;
+        }
+
+        data->membase = ioremap(res.start, size);
+        if (!data->membase) {
+                ret = -ENOMEM;
+                goto err_alloc;
+        }
+
+        data->rcdev.owner = THIS_MODULE;
+        data->rcdev.nr_resets = size * 32;
+        data->rcdev.ops = &sunxi_reset_ops;
+        data->rcdev.of_node = np;
+        reset_controller_register(&data->rcdev);
+
+        return 0;
+
+err_alloc:
+        kfree(data);
+        return ret;
+};
+
+/*
+ * These are the reset controller we need to initialize early on in
+ * our system, before we can even think of using a regular device
+ * driver for it.
+ */
+static const struct of_device_id sunxi_early_reset_dt_ids[] __initdata = {
+        { .compatible = "allwinner,sun6i-a31-ahb1-reset", },
+        { /* sentinel */ },
+};
+
+void __init sun6i_reset_init(void)
+{
+        struct device_node *np;
+
+        for_each_matching_node(np, sunxi_early_reset_dt_ids)
+                sunxi_reset_init(np);
+}
+
+/*
+ * And these are the controllers we can register through the regular
+ * device model.
+ */
+static const struct of_device_id sunxi_reset_dt_ids[] = {
+         { .compatible = "allwinner,sun6i-a31-clock-reset", },
+         { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, sunxi_reset_dt_ids);
+
+static int sunxi_reset_probe(struct platform_device *pdev)
+{
+        return sunxi_reset_init(pdev->dev.of_node);
+}
+
+static int sunxi_reset_remove(struct platform_device *pdev)
+{
+        struct sunxi_reset_data *data = platform_get_drvdata(pdev);
+
+        reset_controller_unregister(&data->rcdev);
+        iounmap(data->membase);
+        kfree(data);
+
+        return 0;
+}
+
+static struct platform_driver sunxi_reset_driver = {
+        .probe  = sunxi_reset_probe,
+        .remove = sunxi_reset_remove,
+        .driver = {
+                .name           = "sunxi-reset",
+                .owner          = THIS_MODULE,
+                .of_match_table = sunxi_reset_dt_ids,
+        },
+};
+module_platform_driver(sunxi_reset_driver);
+
+MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com");
+MODULE_DESCRIPTION("Allwinner SoCs Reset Controller Driver");
+MODULE_LICENSE("GPL");