drivers/acpi/arm64/amba.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2
   3 /*
   4  * ACPI support for platform bus type.
   5  *
   6  * Copyright (C) 2015, Linaro Ltd
   7  * Author: Graeme Gregory <graeme.gregory@linaro.org>
   8  */
   9
  10 #include <linux/acpi.h>
  11 #include <linux/amba/bus.h>
  12 #include <linux/clkdev.h>
  13 #include <linux/clk-provider.h>
  14 #include <linux/device.h>
  15 #include <linux/err.h>
  16 #include <linux/ioport.h>
  17 #include <linux/kernel.h>
  18 #include <linux/module.h>
  19
  20 #include "init.h"
  21
  22 static const struct acpi_device_id amba_id_list[] = {
  23         {"ARMH0061", 0}, /* PL061 GPIO Device */
  24         {"ARMH0330", 0}, /* ARM DMA Controller DMA-330 */
  25         {"", 0},
  26 };
  27
  28 static void amba_register_dummy_clk(void)
  29 {
  30         struct clk *amba_dummy_clk;
  31
  32         amba_dummy_clk = clk_register_fixed_rate(NULL, "apb_pclk", NULL, 0, 0);
  33         clk_register_clkdev(amba_dummy_clk, "apb_pclk", NULL);
  34 }
  35
  36 static int amba_handler_attach(struct acpi_device *adev,
  37                                 const struct acpi_device_id *id)
  38 {
  39         struct acpi_device *parent = acpi_dev_parent(adev);
  40         struct amba_device *dev;
  41         struct resource_entry *rentry;
  42         struct list_head resource_list;
  43         bool address_found = false;
  44         int irq_no = 0;
  45         int ret;
  46
  47         /* If the ACPI node already has a physical device attached, skip it. */
  48         if (adev->physical_node_count)
  49                 return 0;
  50
  51         dev = amba_device_alloc(dev_name(&adev->dev), 0, 0);
  52         if (!dev) {
  53                 dev_err(&adev->dev, "%s(): amba_device_alloc() failed\n",
  54                         __func__);
  55                 return -ENOMEM;
  56         }
  57
  58         INIT_LIST_HEAD(&resource_list);
  59         ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
  60         if (ret < 0)
  61                 goto err_free;
  62
  63         list_for_each_entry(rentry, &resource_list, node) {
  64                 switch (resource_type(rentry->res)) {
  65                 case IORESOURCE_MEM:
  66                         if (!address_found) {
  67                                 dev->res = *rentry->res;
  68                                 dev->res.name = dev_name(&dev->dev);
  69                                 address_found = true;
  70                         }
  71                         break;
  72                 case IORESOURCE_IRQ:
  73                         if (irq_no < AMBA_NR_IRQS)
  74                                 dev->irq[irq_no++] = rentry->res->start;
  75                         break;
  76                 default:
  77                         dev_warn(&adev->dev, "Invalid resource\n");
  78                         break;
  79                 }
  80         }
  81
  82         acpi_dev_free_resource_list(&resource_list);
  83
  84         /*
  85          * If the ACPI node has a parent and that parent has a physical device
  86          * attached to it, that physical device should be the parent of
  87          * the amba device we are about to create.
  88          */
  89         if (parent)
  90                 dev->dev.parent = acpi_get_first_physical_node(parent);
  91
  92         device_set_node(&dev->dev, acpi_fwnode_handle(adev));
  93
  94         ret = amba_device_add(dev, &iomem_resource);
  95         if (ret) {
  96                 dev_err(&adev->dev, "%s(): amba_device_add() failed (%d)\n",
  97                        __func__, ret);
  98                 goto err_free;
  99         }
 100
 101         return 1;
 102
 103 err_free:
 104         amba_device_put(dev);
 105         return ret;
 106 }
 107
 108 static struct acpi_scan_handler amba_handler = {
 109         .ids = amba_id_list,
 110         .attach = amba_handler_attach,
 111 };
 112
 113 void __init acpi_amba_init(void)
 114 {
 115         amba_register_dummy_clk();
 116         acpi_scan_add_handler(&amba_handler);
 117 }