LXR linux/drivers/reset/reset-sunxi.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Allwinner SoCs Reset Controller driver
   4 *
   5 * Copyright 2013 Maxime Ripard
   6 *
   7 * Maxime Ripard <maxime.ripard@free-electrons.com>
   8 */
   9
  10#include <linux/err.h>
  11#include <linux/io.h>
  12#include <linux/init.h>
  13#include <linux/of.h>
  14#include <linux/of_address.h>
  15#include <linux/platform_device.h>
  16#include <linux/reset-controller.h>
  17#include <linux/reset/reset-simple.h>
  18#include <linux/reset/sunxi.h>
  19#include <linux/slab.h>
  20#include <linux/spinlock.h>
  21#include <linux/types.h>
  22
  23static int sunxi_reset_init(struct device_node *np)
  24{
  25        struct reset_simple_data *data;
  26        struct resource res;
  27        resource_size_t size;
  28        int ret;
  29
  30        data = kzalloc(sizeof(*data), GFP_KERNEL);
  31        if (!data)
  32                return -ENOMEM;
  33
  34        ret = of_address_to_resource(np, 0, &res);
  35        if (ret)
  36                goto err_alloc;
  37
  38        size = resource_size(&res);
  39        if (!request_mem_region(res.start, size, np->name)) {
  40                ret = -EBUSY;
  41                goto err_alloc;
  42        }
  43
  44        data->membase = ioremap(res.start, size);
  45        if (!data->membase) {
  46                ret = -ENOMEM;
  47                goto err_alloc;
  48        }
  49
  50        spin_lock_init(&data->lock);
  51
  52        data->rcdev.owner = THIS_MODULE;
  53        data->rcdev.nr_resets = size * 8;
  54        data->rcdev.ops = &reset_simple_ops;
  55        data->rcdev.of_node = np;
  56        data->active_low = true;
  57
  58        return reset_controller_register(&data->rcdev);
  59
  60err_alloc:
  61        kfree(data);
  62        return ret;
  63};
  64
  65/*
  66 * These are the reset controller we need to initialize early on in
  67 * our system, before we can even think of using a regular device
  68 * driver for it.
  69 * The controllers that we can register through the regular device
  70 * model are handled by the simple reset driver directly.
  71 */
  72static const struct of_device_id sunxi_early_reset_dt_ids[] __initconst = {
  73        { .compatible = "allwinner,sun6i-a31-ahb1-reset", },
  74        { /* sentinel */ },
  75};
  76
  77void __init sun6i_reset_init(void)
  78{
  79        struct device_node *np;
  80
  81        for_each_matching_node(np, sunxi_early_reset_dt_ids)
  82                sunxi_reset_init(np);
  83}
  84