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         {"ARMH0330", 0}, /* ARM DMA Controller DMA-330 */
  25         {"ARMHC500", 0}, /* ARM CoreSight ETM4x */
  26         {"ARMHC501", 0}, /* ARM CoreSight ETR */
  27         {"ARMHC502", 0}, /* ARM CoreSight STM */
  28         {"ARMHC503", 0}, /* ARM CoreSight Debug */
  29         {"ARMHC979", 0}, /* ARM CoreSight TPIU */
  30         {"ARMHC97C", 0}, /* ARM CoreSight SoC-400 TMC, SoC-600 ETF/ETB */
  31         {"ARMHC98D", 0}, /* ARM CoreSight Dynamic Replicator */
  32         {"ARMHC9CA", 0}, /* ARM CoreSight CATU */
  33         {"ARMHC9FF", 0}, /* ARM CoreSight Dynamic Funnel */
  34         {"", 0},
  35 };
  36
  37 static void amba_register_dummy_clk(void)
  38 {
  39         static struct clk *amba_dummy_clk;
  40
  41         /* If clock already registered */
  42         if (amba_dummy_clk)
  43                 return;
  44
  45         amba_dummy_clk = clk_register_fixed_rate(NULL, "apb_pclk", NULL, 0, 0);
  46         clk_register_clkdev(amba_dummy_clk, "apb_pclk", NULL);
  47 }
  48
  49 static int amba_handler_attach(struct acpi_device *adev,
  50                                 const struct acpi_device_id *id)
  51 {
  52         struct acpi_device *parent = acpi_dev_parent(adev);
  53         struct amba_device *dev;
  54         struct resource_entry *rentry;
  55         struct list_head resource_list;
  56         bool address_found = false;
  57         int irq_no = 0;
  58         int ret;
  59
  60         /* If the ACPI node already has a physical device attached, skip it. */
  61         if (adev->physical_node_count)
  62                 return 0;
  63
  64         dev = amba_device_alloc(dev_name(&adev->dev), 0, 0);
  65         if (!dev) {
  66                 dev_err(&adev->dev, "%s(): amba_device_alloc() failed\n",
  67                         __func__);
  68                 return -ENOMEM;
  69         }
  70
  71         INIT_LIST_HEAD(&resource_list);
  72         ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
  73         if (ret < 0)
  74                 goto err_free;
  75
  76         list_for_each_entry(rentry, &resource_list, node) {
  77                 switch (resource_type(rentry->res)) {
  78                 case IORESOURCE_MEM:
  79                         if (!address_found) {
  80                                 dev->res = *rentry->res;
  81                                 dev->res.name = dev_name(&dev->dev);
  82                                 address_found = true;
  83                         }
  84                         break;
  85                 case IORESOURCE_IRQ:
  86                         if (irq_no < AMBA_NR_IRQS)
  87                                 dev->irq[irq_no++] = rentry->res->start;
  88                         break;
  89                 default:
  90                         dev_warn(&adev->dev, "Invalid resource\n");
  91                         break;
  92                 }
  93         }
  94
  95         acpi_dev_free_resource_list(&resource_list);
  96
  97         /*
  98          * If the ACPI node has a parent and that parent has a physical device
  99          * attached to it, that physical device should be the parent of
 100          * the amba device we are about to create.
 101          */
 102         if (parent)
 103                 dev->dev.parent = acpi_get_first_physical_node(parent);
 104
 105         ACPI_COMPANION_SET(&dev->dev, adev);
 106
 107         ret = amba_device_add(dev, &iomem_resource);
 108         if (ret) {
 109                 dev_err(&adev->dev, "%s(): amba_device_add() failed (%d)\n",
 110                        __func__, ret);
 111                 goto err_free;
 112         }
 113
 114         return 1;
 115
 116 err_free:
 117         amba_device_put(dev);
 118         return ret;
 119 }
 120
 121 static struct acpi_scan_handler amba_handler = {
 122         .ids = amba_id_list,
 123         .attach = amba_handler_attach,
 124 };
 125
 126 void __init acpi_amba_init(void)
 127 {
 128         amba_register_dummy_clk();
 129         acpi_scan_add_handler(&amba_handler);
 130 }