121 lines · c
1// SPDX-License-Identifier: GPL-2.02/*3 * Copyright (C) 2018, Intel Corporation4 * Copied from reset-sunxi.c5 */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/reset-simple.h>15#include <linux/reset/socfpga.h>16#include <linux/slab.h>17#include <linux/spinlock.h>18#include <linux/types.h>19 20#define SOCFPGA_NR_BANKS 821 22static int a10_reset_init(struct device_node *np)23{24 struct reset_simple_data *data;25 struct resource res;26 resource_size_t size;27 int ret;28 u32 reg_offset = 0x10;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 release_region;48 }49 50 if (of_property_read_u32(np, "altr,modrst-offset", ®_offset))51 pr_warn("missing altr,modrst-offset property, assuming 0x10\n");52 data->membase += reg_offset;53 54 spin_lock_init(&data->lock);55 56 data->rcdev.owner = THIS_MODULE;57 data->rcdev.nr_resets = SOCFPGA_NR_BANKS * 32;58 data->rcdev.ops = &reset_simple_ops;59 data->rcdev.of_node = np;60 data->status_active_low = true;61 62 ret = reset_controller_register(&data->rcdev);63 if (ret)64 pr_err("unable to register device\n");65 66 return ret;67 68release_region:69 release_mem_region(res.start, size);70 71err_alloc:72 kfree(data);73 return ret;74};75 76/*77 * These are the reset controller we need to initialize early on in78 * our system, before we can even think of using a regular device79 * driver for it.80 * The controllers that we can register through the regular device81 * model are handled by the simple reset driver directly.82 */83static const struct of_device_id socfpga_early_reset_dt_ids[] __initconst = {84 { .compatible = "altr,rst-mgr", },85 { /* sentinel */ },86};87 88void __init socfpga_reset_init(void)89{90 struct device_node *np;91 92 for_each_matching_node(np, socfpga_early_reset_dt_ids)93 a10_reset_init(np);94}95 96/*97 * The early driver is problematic, because it doesn't register98 * itself as a driver. This causes certain device links to prevent99 * consumer devices from probing. The hacky solution is to register100 * an empty driver, whose only job is to attach itself to the reset101 * manager and call probe.102 */103static const struct of_device_id socfpga_reset_dt_ids[] = {104 { .compatible = "altr,rst-mgr", },105 { /* sentinel */ },106};107 108static int reset_simple_probe(struct platform_device *pdev)109{110 return 0;111}112 113static struct platform_driver reset_socfpga_driver = {114 .probe = reset_simple_probe,115 .driver = {116 .name = "socfpga-reset",117 .of_match_table = socfpga_reset_dt_ids,118 },119};120builtin_platform_driver(reset_socfpga_driver);121