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