84 lines · c
1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Allwinner SoCs Reset Controller driver4 *5 * Copyright 2013 Maxime Ripard6 *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 in67 * our system, before we can even think of using a regular device68 * driver for it.69 * The controllers that we can register through the regular device70 * 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