1 /* 2 * Allwinner SoCs Reset Controller driver 3 * 4 * Copyright 2013 Maxime Ripard 5 * 6 * Maxime Ripard <maxime.ripard@free-electrons.com> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 */ 13 14 #include <linux/err.h> 15 #include <linux/io.h> 16 #include <linux/init.h> 17 #include <linux/of.h> 18 #include <linux/of_address.h> 19 #include <linux/platform_device.h> 20 #include <linux/reset-controller.h> 21 #include <linux/slab.h> 22 #include <linux/spinlock.h> 23 #include <linux/types.h> 24 25 #include "reset-simple.h" 26 27 static int sunxi_reset_init(struct device_node *np) 28 { 29 struct reset_simple_data *data; 30 struct resource res; 31 resource_size_t size; 32 int ret; 33 34 data = kzalloc(sizeof(*data), GFP_KERNEL); 35 if (!data) 36 return -ENOMEM; 37 38 ret = of_address_to_resource(np, 0, &res); 39 if (ret) 40 goto err_alloc; 41 42 size = resource_size(&res); 43 if (!request_mem_region(res.start, size, np->name)) { 44 ret = -EBUSY; 45 goto err_alloc; 46 } 47 48 data->membase = ioremap(res.start, size); 49 if (!data->membase) { 50 ret = -ENOMEM; 51 goto err_alloc; 52 } 53 54 spin_lock_init(&data->lock); 55 56 data->rcdev.owner = THIS_MODULE; 57 data->rcdev.nr_resets = size * 8; 58 data->rcdev.ops = &reset_simple_ops; 59 data->rcdev.of_node = np; 60 data->active_low = true; 61 62 return reset_controller_register(&data->rcdev); 63 64 err_alloc: 65 kfree(data); 66 return ret; 67 }; 68 69 /* 70 * These are the reset controller we need to initialize early on in 71 * our system, before we can even think of using a regular device 72 * driver for it. 73 * The controllers that we can register through the regular device 74 * model are handled by the simple reset driver directly. 75 */ 76 static const struct of_device_id sunxi_early_reset_dt_ids[] __initconst = { 77 { .compatible = "allwinner,sun6i-a31-ahb1-reset", }, 78 { /* sentinel */ }, 79 }; 80 81 void __init sun6i_reset_init(void) 82 { 83 struct device_node *np; 84 85 for_each_matching_node(np, sunxi_early_reset_dt_ids) 86 sunxi_reset_init(np); 87 } 88