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Diffstat (limited to 'drivers/reset/reset-sunxi.c')
-rw-r--r--drivers/reset/reset-sunxi.c83
1 files changed, 83 insertions, 0 deletions
diff --git a/drivers/reset/reset-sunxi.c b/drivers/reset/reset-sunxi.c
new file mode 100644
index 000000000..e752594b6
--- /dev/null
+++ b/drivers/reset/reset-sunxi.c
@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Allwinner SoCs Reset Controller driver
+ *
+ * Copyright 2013 Maxime Ripard
+ *
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ */
+
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+#include <linux/reset/reset-simple.h>
+#include <linux/reset/sunxi.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+static int sunxi_reset_init(struct device_node *np)
+{
+ struct reset_simple_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;
+ }
+
+ spin_lock_init(&data->lock);
+
+ data->rcdev.owner = THIS_MODULE;
+ data->rcdev.nr_resets = size * 8;
+ data->rcdev.ops = &reset_simple_ops;
+ data->rcdev.of_node = np;
+ data->active_low = true;
+
+ return reset_controller_register(&data->rcdev);
+
+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.
+ * The controllers that we can register through the regular device
+ * model are handled by the simple reset driver directly.
+ */
+static const struct of_device_id sunxi_early_reset_dt_ids[] __initconst = {
+ { .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);
+}