xref: /openbmc/linux/drivers/acpi/arm64/amba.c (revision fc001b36)
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 
amba_register_dummy_clk(void)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 
amba_handler_attach(struct acpi_device * adev,const struct acpi_device_id * id)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 
acpi_amba_init(void)125 void __init acpi_amba_init(void)
126 {
127 	amba_register_dummy_clk();
128 	acpi_scan_add_handler(&amba_handler);
129 }
130