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         {"ARMHC501", 0}, /* ARM CoreSight ETR */
  26         {"ARMHC502", 0}, /* ARM CoreSight STM */
  27         {"ARMHC503", 0}, /* ARM CoreSight Debug */
  28         {"ARMHC979", 0}, /* ARM CoreSight TPIU */
  29         {"ARMHC97C", 0}, /* ARM CoreSight SoC-400 TMC, SoC-600 ETF/ETB */
  30         {"ARMHC98D", 0}, /* ARM CoreSight Dynamic Replicator */
  31         {"ARMHC9CA", 0}, /* ARM CoreSight CATU */
  32         {"ARMHC9FF", 0}, /* ARM CoreSight Dynamic Funnel */
  33         {"", 0},
  34 };
  35
  36 static void amba_register_dummy_clk(void)
  37 {
  38         static struct clk *amba_dummy_clk;
  39
  40         /* If clock already registered */
  41         if (amba_dummy_clk)
  42                 return;
  43
  44         amba_dummy_clk = clk_register_fixed_rate(NULL, "apb_pclk", NULL, 0, 0);
  45         clk_register_clkdev(amba_dummy_clk, "apb_pclk", NULL);
  46 }
  47
  48 static int amba_handler_attach(struct acpi_device *adev,
  49                                 const struct acpi_device_id *id)
  50 {
  51         struct acpi_device *parent = acpi_dev_parent(adev);
  52         struct amba_device *dev;
  53         struct resource_entry *rentry;
  54         struct list_head resource_list;
  55         bool address_found = false;
  56         int irq_no = 0;
  57         int ret;
  58
  59         /* If the ACPI node already has a physical device attached, skip it. */
  60         if (adev->physical_node_count)
  61                 return 0;
  62
  63         dev = amba_device_alloc(dev_name(&adev->dev), 0, 0);
  64         if (!dev) {
  65                 dev_err(&adev->dev, "%s(): amba_device_alloc() failed\n",
  66                         __func__);
  67                 return -ENOMEM;
  68         }
  69
  70         INIT_LIST_HEAD(&resource_list);
  71         ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
  72         if (ret < 0)
  73                 goto err_free;
  74
  75         list_for_each_entry(rentry, &resource_list, node) {
  76                 switch (resource_type(rentry->res)) {
  77                 case IORESOURCE_MEM:
  78                         if (!address_found) {
  79                                 dev->res = *rentry->res;
  80                                 dev->res.name = dev_name(&dev->dev);
  81                                 address_found = true;
  82                         }
  83                         break;
  84                 case IORESOURCE_IRQ:
  85                         if (irq_no < AMBA_NR_IRQS)
  86                                 dev->irq[irq_no++] = rentry->res->start;
  87                         break;
  88                 default:
  89                         dev_warn(&adev->dev, "Invalid resource\n");
  90                         break;
  91                 }
  92         }
  93
  94         acpi_dev_free_resource_list(&resource_list);
  95
  96         /*
  97          * If the ACPI node has a parent and that parent has a physical device
  98          * attached to it, that physical device should be the parent of
  99          * the amba device we are about to create.
 100          */
 101         if (parent)
 102                 dev->dev.parent = acpi_get_first_physical_node(parent);
 103
 104         ACPI_COMPANION_SET(&dev->dev, adev);
 105
 106         ret = amba_device_add(dev, &iomem_resource);
 107         if (ret) {
 108                 dev_err(&adev->dev, "%s(): amba_device_add() failed (%d)\n",
 109                        __func__, ret);
 110                 goto err_free;
 111         }
 112
 113         return 1;
 114
 115 err_free:
 116         amba_device_put(dev);
 117         return ret;
 118 }
 119
 120 static struct acpi_scan_handler amba_handler = {
 121         .ids = amba_id_list,
 122         .attach = amba_handler_attach,
 123 };
 124
 125 void __init acpi_amba_init(void)
 126 {
 127         amba_register_dummy_clk();
 128         acpi_scan_add_handler(&amba_handler);
 129 }