1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2018, Intel Corporation 4 * Copied from reset-sunxi.c 5 */ 6 7 #include <linux/err.h> 8 #include <linux/io.h> 9 #include <linux/init.h> 10 #include <linux/of.h> 11 #include <linux/of_address.h> 12 #include <linux/platform_device.h> 13 #include <linux/reset-controller.h> 14 #include <linux/reset/socfpga.h> 15 #include <linux/slab.h> 16 #include <linux/spinlock.h> 17 #include <linux/types.h> 18 19 #include "reset-simple.h" 20 21 #define SOCFPGA_NR_BANKS 8 22 23 static int a10_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 u32 reg_offset = 0x10; 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 if (of_property_read_u32(np, "altr,modrst-offset", ®_offset)) 52 pr_warn("missing altr,modrst-offset property, assuming 0x10\n"); 53 data->membase += reg_offset; 54 55 spin_lock_init(&data->lock); 56 57 data->rcdev.owner = THIS_MODULE; 58 data->rcdev.nr_resets = SOCFPGA_NR_BANKS * 32; 59 data->rcdev.ops = &reset_simple_ops; 60 data->rcdev.of_node = np; 61 data->status_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 socfpga_early_reset_dt_ids[] __initconst = { 78 { .compatible = "altr,rst-mgr", }, 79 { /* sentinel */ }, 80 }; 81 82 void __init socfpga_reset_init(void) 83 { 84 struct device_node *np; 85 86 for_each_matching_node(np, socfpga_early_reset_dt_ids) 87 a10_reset_init(np); 88 } 89