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path: root/drivers/reset/reset-socfpga.c
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Diffstat (limited to 'drivers/reset/reset-socfpga.c')
-rw-r--r--drivers/reset/reset-socfpga.c120
1 files changed, 120 insertions, 0 deletions
diff --git a/drivers/reset/reset-socfpga.c b/drivers/reset/reset-socfpga.c
new file mode 100644
index 000000000..8c6492e56
--- /dev/null
+++ b/drivers/reset/reset-socfpga.c
@@ -0,0 +1,120 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2018, Intel Corporation
+ * Copied from reset-sunxi.c
+ */
+
+#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/socfpga.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#define SOCFPGA_NR_BANKS 8
+
+static int a10_reset_init(struct device_node *np)
+{
+ struct reset_simple_data *data;
+ struct resource res;
+ resource_size_t size;
+ int ret;
+ u32 reg_offset = 0x10;
+
+ 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 release_region;
+ }
+
+ if (of_property_read_u32(np, "altr,modrst-offset", &reg_offset))
+ pr_warn("missing altr,modrst-offset property, assuming 0x10\n");
+ data->membase += reg_offset;
+
+ spin_lock_init(&data->lock);
+
+ data->rcdev.owner = THIS_MODULE;
+ data->rcdev.nr_resets = SOCFPGA_NR_BANKS * 32;
+ data->rcdev.ops = &reset_simple_ops;
+ data->rcdev.of_node = np;
+ data->status_active_low = true;
+
+ ret = reset_controller_register(&data->rcdev);
+ if (ret)
+ pr_err("unable to register device\n");
+
+ return ret;
+
+release_region:
+ release_mem_region(res.start, size);
+
+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 socfpga_early_reset_dt_ids[] __initconst = {
+ { .compatible = "altr,rst-mgr", },
+ { /* sentinel */ },
+};
+
+void __init socfpga_reset_init(void)
+{
+ struct device_node *np;
+
+ for_each_matching_node(np, socfpga_early_reset_dt_ids)
+ a10_reset_init(np);
+}
+
+/*
+ * The early driver is problematic, because it doesn't register
+ * itself as a driver. This causes certain device links to prevent
+ * consumer devices from probing. The hacky solution is to register
+ * an empty driver, whose only job is to attach itself to the reset
+ * manager and call probe.
+ */
+static const struct of_device_id socfpga_reset_dt_ids[] = {
+ { .compatible = "altr,rst-mgr", },
+ { /* sentinel */ },
+};
+
+static int reset_simple_probe(struct platform_device *pdev)
+{
+ return 0;
+}
+
+static struct platform_driver reset_socfpga_driver = {
+ .probe = reset_simple_probe,
+ .driver = {
+ .name = "socfpga-reset",
+ .of_match_table = socfpga_reset_dt_ids,
+ },
+};
+builtin_platform_driver(reset_socfpga_driver);