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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
20DEFINE_MUTEX(psr_mutex);
21
22static struct kobject *psr_kobj;
23
24struct psr_attr {
25 u32 handle;
26 struct kobj_attribute attr;
27} *psr_attrs;
28
29static 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
72out:
73 mutex_unlock(&psr_mutex);
74out_token:
75 opal_async_release_token(token);
76 return ret;
77}
78
79static 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
120out:
121 mutex_unlock(&psr_mutex);
122out_token:
123 opal_async_release_token(token);
124 return ret;
125}
126
127void __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(*psr_attrs),
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;
171out_kobj:
172 kobject_put(psr_kobj);
173out:
174 kfree(psr_attrs);
175}
176
