drivers/reset/reset-socfpga.c

   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/slab.h>
  15 #include <linux/spinlock.h>
  16 #include <linux/types.h>
  17
  18 #include "reset-simple.h"
  19
  20 #define SOCFPGA_NR_BANKS        8
  21 void __init socfpga_reset_init(void);
  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", &reg_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 }