1
2 /*
3 * ACPI support for platform bus type.
4 *
5 * Copyright (C) 2015, Linaro Ltd
6 * Author: Graeme Gregory <graeme.gregory@linaro.org>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13 #include <linux/acpi.h>
14 #include <linux/amba/bus.h>
15 #include <linux/clkdev.h>
16 #include <linux/clk-provider.h>
17 #include <linux/device.h>
18 #include <linux/err.h>
19 #include <linux/ioport.h>
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22
23 #include "internal.h"
24
25 static const struct acpi_device_id amba_id_list[] = {
26 {"ARMH0061", 0}, /* PL061 GPIO Device */
27 {"", 0},
28 };
29
amba_register_dummy_clk(void)30 static void amba_register_dummy_clk(void)
31 {
32 static struct clk *amba_dummy_clk;
33
34 /* If clock already registered */
35 if (amba_dummy_clk)
36 return;
37
38 amba_dummy_clk = clk_register_fixed_rate(NULL, "apb_pclk", NULL, 0, 0);
39 clk_register_clkdev(amba_dummy_clk, "apb_pclk", NULL);
40 }
41
amba_handler_attach(struct acpi_device * adev,const struct acpi_device_id * id)42 static int amba_handler_attach(struct acpi_device *adev,
43 const struct acpi_device_id *id)
44 {
45 struct amba_device *dev;
46 struct resource_entry *rentry;
47 struct list_head resource_list;
48 bool address_found = false;
49 int irq_no = 0;
50 int ret;
51
52 /* If the ACPI node already has a physical device attached, skip it. */
53 if (adev->physical_node_count)
54 return 0;
55
56 dev = amba_device_alloc(dev_name(&adev->dev), 0, 0);
57 if (!dev) {
58 dev_err(&adev->dev, "%s(): amba_device_alloc() failed\n",
59 __func__);
60 return -ENOMEM;
61 }
62
63 INIT_LIST_HEAD(&resource_list);
64 ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
65 if (ret < 0)
66 goto err_free;
67
68 list_for_each_entry(rentry, &resource_list, node) {
69 switch (resource_type(rentry->res)) {
70 case IORESOURCE_MEM:
71 if (!address_found) {
72 dev->res = *rentry->res;
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 (adev->parent)
94 dev->dev.parent = acpi_get_first_physical_node(adev->parent);
95
96 ACPI_COMPANION_SET(&dev->dev, 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
acpi_amba_init(void)117 void __init acpi_amba_init(void)
118 {
119 amba_register_dummy_clk();
120 acpi_scan_add_handler(&amba_handler);
121 }
122