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/reset/sunxi.h> 22 #include <linux/slab.h> 23 #include <linux/spinlock.h> 24 #include <linux/types.h> 25 26 #include "reset-simple.h" 27 28 static int sunxi_reset_init(struct device_node *np) 29 { 30 struct reset_simple_data *data; 31 struct resource res; 32 resource_size_t size; 33 int ret; 34 35 data = kzalloc(sizeof(*data), GFP_KERNEL); 36 if (!data) 37 return -ENOMEM; 38 39 ret = of_address_to_resource(np, 0, &res); 40 if (ret) 41 goto err_alloc; 42 43 size = resource_size(&res); 44 if (!request_mem_region(res.start, size, np->name)) { 45 ret = -EBUSY; 46 goto err_alloc; 47 } 48 49 data->membase = ioremap(res.start, size); 50 if (!data->membase) { 51 ret = -ENOMEM; 52 goto err_alloc; 53 } 54 55 spin_lock_init(&data->lock); 56 57 data->rcdev.owner = THIS_MODULE; 58 data->rcdev.nr_resets = size * 8; 59 data->rcdev.ops = &reset_simple_ops; 60 data->rcdev.of_node = np; 61 data->active_low = true; 62 63 return reset_controller_register(&data->rcdev); 64 65 err_alloc: 66 kfree(data); 67 return ret; 68 }; 69 70 /* 71 * These are the reset controller we need to initialize early on in 72 * our system, before we can even think of using a regular device 73 * driver for it. 74 * The controllers that we can register through the regular device 75 * model are handled by the simple reset driver directly. 76 */ 77 static const struct of_device_id sunxi_early_reset_dt_ids[] __initconst = { 78 { .compatible = "allwinner,sun6i-a31-ahb1-reset", }, 79 { /* sentinel */ }, 80 }; 81 82 void __init sun6i_reset_init(void) 83 { 84 struct device_node *np; 85 86 for_each_matching_node(np, sunxi_early_reset_dt_ids) 87 sunxi_reset_init(np); 88 } 89