1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * PowerNV OPAL Power-Shift-Ratio interface
5 * Copyright 2017 IBM Corp.
8 #define pr_fmt(fmt) "opal-psr: " fmt
11 #include <linux/kobject.h>
12 #include <linux/slab.h>
16 static DEFINE_MUTEX(psr_mutex
);
18 static struct kobject
*psr_kobj
;
20 static struct psr_attr
{
22 struct kobj_attribute attr
;
25 static ssize_t
psr_show(struct kobject
*kobj
, struct kobj_attribute
*attr
,
28 struct psr_attr
*psr_attr
= container_of(attr
, struct psr_attr
, attr
);
32 token
= opal_async_get_token_interruptible();
34 pr_devel("Failed to get token\n");
38 ret
= mutex_lock_interruptible(&psr_mutex
);
42 ret
= opal_get_power_shift_ratio(psr_attr
->handle
, token
,
45 case OPAL_ASYNC_COMPLETION
:
46 ret
= opal_async_wait_response(token
, &msg
);
48 pr_devel("Failed to wait for the async response\n");
52 ret
= opal_error_code(opal_get_async_rc(msg
));
54 ret
= sprintf(buf
, "%u\n", be32_to_cpu(psr
));
60 ret
= sprintf(buf
, "%u\n", be32_to_cpu(psr
));
65 ret
= opal_error_code(ret
);
69 mutex_unlock(&psr_mutex
);
71 opal_async_release_token(token
);
75 static ssize_t
psr_store(struct kobject
*kobj
, struct kobj_attribute
*attr
,
76 const char *buf
, size_t count
)
78 struct psr_attr
*psr_attr
= container_of(attr
, struct psr_attr
, attr
);
82 ret
= kstrtoint(buf
, 0, &psr
);
86 token
= opal_async_get_token_interruptible();
88 pr_devel("Failed to get token\n");
92 ret
= mutex_lock_interruptible(&psr_mutex
);
96 ret
= opal_set_power_shift_ratio(psr_attr
->handle
, token
, psr
);
98 case OPAL_ASYNC_COMPLETION
:
99 ret
= opal_async_wait_response(token
, &msg
);
101 pr_devel("Failed to wait for the async response\n");
105 ret
= opal_error_code(opal_get_async_rc(msg
));
113 ret
= opal_error_code(ret
);
117 mutex_unlock(&psr_mutex
);
119 opal_async_release_token(token
);
123 void __init
opal_psr_init(void)
125 struct device_node
*psr
, *node
;
128 psr
= of_find_compatible_node(NULL
, NULL
,
129 "ibm,opal-power-shift-ratio");
131 pr_devel("Power-shift-ratio node not found\n");
135 psr_attrs
= kcalloc(of_get_child_count(psr
), sizeof(*psr_attrs
),
140 psr_kobj
= kobject_create_and_add("psr", opal_kobj
);
142 pr_warn("Failed to create psr kobject\n");
146 for_each_child_of_node(psr
, node
) {
147 if (of_property_read_u32(node
, "handle",
148 &psr_attrs
[i
].handle
))
151 sysfs_attr_init(&psr_attrs
[i
].attr
.attr
);
152 if (of_property_read_string(node
, "label",
153 &psr_attrs
[i
].attr
.attr
.name
))
155 psr_attrs
[i
].attr
.attr
.mode
= 0664;
156 psr_attrs
[i
].attr
.show
= psr_show
;
157 psr_attrs
[i
].attr
.store
= psr_store
;
158 if (sysfs_create_file(psr_kobj
, &psr_attrs
[i
].attr
.attr
)) {
159 pr_devel("Failed to create psr sysfs file %s\n",
160 psr_attrs
[i
].attr
.attr
.name
);
168 kobject_put(psr_kobj
);