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8e84b2d1 SB |
1 | /* |
2 | * PowerNV OPAL Power-Shift-Ratio interface | |
3 | * | |
4 | * Copyright 2017 IBM Corp. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | */ | |
11 | ||
12 | #define pr_fmt(fmt) "opal-psr: " fmt | |
13 | ||
14 | #include <linux/of.h> | |
15 | #include <linux/kobject.h> | |
16 | #include <linux/slab.h> | |
17 | ||
18 | #include <asm/opal.h> | |
19 | ||
20 | DEFINE_MUTEX(psr_mutex); | |
21 | ||
22 | static struct kobject *psr_kobj; | |
23 | ||
24 | struct psr_attr { | |
25 | u32 handle; | |
26 | struct kobj_attribute attr; | |
27 | } *psr_attrs; | |
28 | ||
29 | static ssize_t psr_show(struct kobject *kobj, struct kobj_attribute *attr, | |
30 | char *buf) | |
31 | { | |
32 | struct psr_attr *psr_attr = container_of(attr, struct psr_attr, attr); | |
33 | struct opal_msg msg; | |
34 | int psr, ret, token; | |
35 | ||
36 | token = opal_async_get_token_interruptible(); | |
37 | if (token < 0) { | |
38 | pr_devel("Failed to get token\n"); | |
39 | return token; | |
40 | } | |
41 | ||
42 | ret = mutex_lock_interruptible(&psr_mutex); | |
43 | if (ret) | |
44 | goto out_token; | |
45 | ||
46 | ret = opal_get_power_shift_ratio(psr_attr->handle, token, | |
47 | (u32 *)__pa(&psr)); | |
48 | switch (ret) { | |
49 | case OPAL_ASYNC_COMPLETION: | |
50 | ret = opal_async_wait_response(token, &msg); | |
51 | if (ret) { | |
52 | pr_devel("Failed to wait for the async response\n"); | |
53 | ret = -EIO; | |
54 | goto out; | |
55 | } | |
56 | ret = opal_error_code(opal_get_async_rc(msg)); | |
57 | if (!ret) { | |
58 | ret = sprintf(buf, "%u\n", be32_to_cpu(psr)); | |
59 | if (ret < 0) | |
60 | ret = -EIO; | |
61 | } | |
62 | break; | |
63 | case OPAL_SUCCESS: | |
64 | ret = sprintf(buf, "%u\n", be32_to_cpu(psr)); | |
65 | if (ret < 0) | |
66 | ret = -EIO; | |
67 | break; | |
68 | default: | |
69 | ret = opal_error_code(ret); | |
70 | } | |
71 | ||
72 | out: | |
73 | mutex_unlock(&psr_mutex); | |
74 | out_token: | |
75 | opal_async_release_token(token); | |
76 | return ret; | |
77 | } | |
78 | ||
79 | static ssize_t psr_store(struct kobject *kobj, struct kobj_attribute *attr, | |
80 | const char *buf, size_t count) | |
81 | { | |
82 | struct psr_attr *psr_attr = container_of(attr, struct psr_attr, attr); | |
83 | struct opal_msg msg; | |
84 | int psr, ret, token; | |
85 | ||
86 | ret = kstrtoint(buf, 0, &psr); | |
87 | if (ret) | |
88 | return ret; | |
89 | ||
90 | token = opal_async_get_token_interruptible(); | |
91 | if (token < 0) { | |
92 | pr_devel("Failed to get token\n"); | |
93 | return token; | |
94 | } | |
95 | ||
96 | ret = mutex_lock_interruptible(&psr_mutex); | |
97 | if (ret) | |
98 | goto out_token; | |
99 | ||
100 | ret = opal_set_power_shift_ratio(psr_attr->handle, token, psr); | |
101 | switch (ret) { | |
102 | case OPAL_ASYNC_COMPLETION: | |
103 | ret = opal_async_wait_response(token, &msg); | |
104 | if (ret) { | |
105 | pr_devel("Failed to wait for the async response\n"); | |
106 | ret = -EIO; | |
107 | goto out; | |
108 | } | |
109 | ret = opal_error_code(opal_get_async_rc(msg)); | |
110 | if (!ret) | |
111 | ret = count; | |
112 | break; | |
113 | case OPAL_SUCCESS: | |
114 | ret = count; | |
115 | break; | |
116 | default: | |
117 | ret = opal_error_code(ret); | |
118 | } | |
119 | ||
120 | out: | |
121 | mutex_unlock(&psr_mutex); | |
122 | out_token: | |
123 | opal_async_release_token(token); | |
124 | return ret; | |
125 | } | |
126 | ||
127 | void __init opal_psr_init(void) | |
128 | { | |
129 | struct device_node *psr, *node; | |
130 | int i = 0; | |
131 | ||
132 | psr = of_find_compatible_node(NULL, NULL, | |
133 | "ibm,opal-power-shift-ratio"); | |
134 | if (!psr) { | |
135 | pr_devel("Power-shift-ratio node not found\n"); | |
136 | return; | |
137 | } | |
138 | ||
139 | psr_attrs = kcalloc(of_get_child_count(psr), sizeof(struct psr_attr), | |
140 | GFP_KERNEL); | |
141 | if (!psr_attrs) | |
142 | return; | |
143 | ||
144 | psr_kobj = kobject_create_and_add("psr", opal_kobj); | |
145 | if (!psr_kobj) { | |
146 | pr_warn("Failed to create psr kobject\n"); | |
147 | goto out; | |
148 | } | |
149 | ||
150 | for_each_child_of_node(psr, node) { | |
151 | if (of_property_read_u32(node, "handle", | |
152 | &psr_attrs[i].handle)) | |
153 | goto out_kobj; | |
154 | ||
155 | sysfs_attr_init(&psr_attrs[i].attr.attr); | |
156 | if (of_property_read_string(node, "label", | |
157 | &psr_attrs[i].attr.attr.name)) | |
158 | goto out_kobj; | |
159 | psr_attrs[i].attr.attr.mode = 0664; | |
160 | psr_attrs[i].attr.show = psr_show; | |
161 | psr_attrs[i].attr.store = psr_store; | |
162 | if (sysfs_create_file(psr_kobj, &psr_attrs[i].attr.attr)) { | |
163 | pr_devel("Failed to create psr sysfs file %s\n", | |
164 | psr_attrs[i].attr.attr.name); | |
165 | goto out_kobj; | |
166 | } | |
167 | i++; | |
168 | } | |
169 | ||
170 | return; | |
171 | out_kobj: | |
172 | kobject_put(psr_kobj); | |
173 | out: | |
174 | kfree(psr_attrs); | |
175 | } |