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
amba_register_dummy_clk(void)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
amba_handler_attach(struct acpi_device * adev,const struct acpi_device_id * id)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
acpi_amba_init(void)113 void __init acpi_amba_init(void)
114 {
115 amba_register_dummy_clk();
116 acpi_scan_add_handler(&amba_handler);
117 }
118