drivers/acpi/acpi_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 "internal.h"
  21
  22 static const struct acpi_device_id amba_id_list[] = {
  23         {"ARMH0061", 0}, /* PL061 GPIO Device */
  24         {"ARMHC500", 0}, /* ARM CoreSight ETM4x */
  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 amba_device *dev;
  52         struct resource_entry *rentry;
  53         struct list_head resource_list;
  54         bool address_found = false;
  55         int irq_no = 0;
  56         int ret;
  57
  58         /* If the ACPI node already has a physical device attached, skip it. */
  59         if (adev->physical_node_count)
  60                 return 0;
  61
  62         dev = amba_device_alloc(dev_name(&adev->dev), 0, 0);
  63         if (!dev) {
  64                 dev_err(&adev->dev, "%s(): amba_device_alloc() failed\n",
  65                         __func__);
  66                 return -ENOMEM;
  67         }
  68
  69         INIT_LIST_HEAD(&resource_list);
  70         ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
  71         if (ret < 0)
  72                 goto err_free;
  73
  74         list_for_each_entry(rentry, &resource_list, node) {
  75                 switch (resource_type(rentry->res)) {
  76                 case IORESOURCE_MEM:
  77                         if (!address_found) {
  78                                 dev->res = *rentry->res;
  79                                 dev->res.name = dev_name(&dev->dev);
  80                                 address_found = true;
  81                         }
  82                         break;
  83                 case IORESOURCE_IRQ:
  84                         if (irq_no < AMBA_NR_IRQS)
  85                                 dev->irq[irq_no++] = rentry->res->start;
  86                         break;
  87                 default:
  88                         dev_warn(&adev->dev, "Invalid resource\n");
  89                         break;
  90                 }
  91         }
  92
  93         acpi_dev_free_resource_list(&resource_list);
  94
  95         /*
  96          * If the ACPI node has a parent and that parent has a physical device
  97          * attached to it, that physical device should be the parent of
  98          * the amba device we are about to create.
  99          */
 100         if (adev->parent)
 101                 dev->dev.parent = acpi_get_first_physical_node(adev->parent);
 102
 103         ACPI_COMPANION_SET(&dev->dev, adev);
 104
 105         ret = amba_device_add(dev, &iomem_resource);
 106         if (ret) {
 107                 dev_err(&adev->dev, "%s(): amba_device_add() failed (%d)\n",
 108                        __func__, ret);
 109                 goto err_free;
 110         }
 111
 112         return 1;
 113
 114 err_free:
 115         amba_device_put(dev);
 116         return ret;
 117 }
 118
 119 static struct acpi_scan_handler amba_handler = {
 120         .ids = amba_id_list,
 121         .attach = amba_handler_attach,
 122 };
 123
 124 void __init acpi_amba_init(void)
 125 {
 126         amba_register_dummy_clk();
 127         acpi_scan_add_handler(&amba_handler);
 128 }