mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-11-01 00:48:50 +00:00
3ad60b4b35
The early reset driver doesn't ever probe, which causes consuming devices to be unable to probe. Add an empty driver to set this device as available, allowing consumers to probe. Signed-off-by: Paweł Anikiel <pan@semihalf.com> Link: https://lore.kernel.org/r/20210920124141.1166544-4-pan@semihalf.com Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
120 lines
2.8 KiB
C
120 lines
2.8 KiB
C
// 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);
|