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/sunxi.h> 18 #include <linux/slab.h> 19 #include <linux/spinlock.h> 20 #include <linux/types.h> 21 22 #include "reset-simple.h" 23 24 static int sunxi_reset_init(struct device_node *np) 25 { 26 struct reset_simple_data *data; 27 struct resource res; 28 resource_size_t size; 29 int ret; 30 31 data = kzalloc(sizeof(*data), GFP_KERNEL); 32 if (!data) 33 return -ENOMEM; 34 35 ret = of_address_to_resource(np, 0, &res); 36 if (ret) 37 goto err_alloc; 38 39 size = resource_size(&res); 40 if (!request_mem_region(res.start, size, np->name)) { 41 ret = -EBUSY; 42 goto err_alloc; 43 } 44 45 data->membase = ioremap(res.start, size); 46 if (!data->membase) { 47 ret = -ENOMEM; 48 goto err_alloc; 49 } 50 51 spin_lock_init(&data->lock); 52 53 data->rcdev.owner = THIS_MODULE; 54 data->rcdev.nr_resets = size * 8; 55 data->rcdev.ops = &reset_simple_ops; 56 data->rcdev.of_node = np; 57 data->active_low = true; 58 59 return reset_controller_register(&data->rcdev); 60 61 err_alloc: 62 kfree(data); 63 return ret; 64 }; 65 66 /* 67 * These are the reset controller we need to initialize early on in 68 * our system, before we can even think of using a regular device 69 * driver for it. 70 * The controllers that we can register through the regular device 71 * model are handled by the simple reset driver directly. 72 */ 73 static const struct of_device_id sunxi_early_reset_dt_ids[] __initconst = { 74 { .compatible = "allwinner,sun6i-a31-ahb1-reset", }, 75 { /* sentinel */ }, 76 }; 77 78 void __init sun6i_reset_init(void) 79 { 80 struct device_node *np; 81 82 for_each_matching_node(np, sunxi_early_reset_dt_ids) 83 sunxi_reset_init(np); 84 } 85