tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
22static 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
36static 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
48static 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 address_found = true;
80 }
81 break;
82 case IORESOURCE_IRQ:
83 if (irq_no < AMBA_NR_IRQS)
84 dev->irq[irq_no++] = rentry->res->start;
85 break;
86 default:
87 dev_warn(&adev->dev, "Invalid resource\n");
88 break;
89 }
90 }
91
92 acpi_dev_free_resource_list(&resource_list);
93
94 /*
95 * If the ACPI node has a parent and that parent has a physical device
96 * attached to it, that physical device should be the parent of
97 * the amba device we are about to create.
98 */
99 if (adev->parent)
100 dev->dev.parent = acpi_get_first_physical_node(adev->parent);
101
102 ACPI_COMPANION_SET(&dev->dev, adev);
103
104 ret = amba_device_add(dev, &iomem_resource);
105 if (ret) {
106 dev_err(&adev->dev, "%s(): amba_device_add() failed (%d)\n",
107 __func__, ret);
108 goto err_free;
109 }
110
111 return 1;
112
113err_free:
114 amba_device_put(dev);
115 return ret;
116}
117
118static struct acpi_scan_handler amba_handler = {
119 .ids = amba_id_list,
120 .attach = amba_handler_attach,
121};
122
123void __init acpi_amba_init(void)
124{
125 amba_register_dummy_clk();
126 acpi_scan_add_handler(&amba_handler);
127}