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// 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", ®_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);
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