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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* PowerNV OPAL Power-Shift-Ratio interface
*
* Copyright 2017 IBM Corp.
*/
#define pr_fmt(fmt) "opal-psr: " fmt
#include <linux/of.h>
#include <linux/kobject.h>
#include <linux/slab.h>
#include <asm/opal.h>
static DEFINE_MUTEX(psr_mutex);
static struct kobject *psr_kobj;
static struct psr_attr {
u32 handle;
struct kobj_attribute attr;
} *psr_attrs;
static ssize_t psr_show(struct kobject *kobj, struct kobj_attribute *attr,
char *buf)
{
struct psr_attr *psr_attr = container_of(attr, struct psr_attr, attr);
struct opal_msg msg;
int psr, ret, token;
token = opal_async_get_token_interruptible();
if (token < 0) {
pr_devel("Failed to get token\n");
return token;
}
ret = mutex_lock_interruptible(&psr_mutex);
if (ret)
goto out_token;
ret = opal_get_power_shift_ratio(psr_attr->handle, token,
(u32 *)__pa(&psr));
switch (ret) {
case OPAL_ASYNC_COMPLETION:
ret = opal_async_wait_response(token, &msg);
if (ret) {
pr_devel("Failed to wait for the async response\n");
ret = -EIO;
goto out;
}
ret = opal_error_code(opal_get_async_rc(msg));
if (!ret) {
ret = sprintf(buf, "%u\n", be32_to_cpu(psr));
if (ret < 0)
ret = -EIO;
}
break;
case OPAL_SUCCESS:
ret = sprintf(buf, "%u\n", be32_to_cpu(psr));
if (ret < 0)
ret = -EIO;
break;
default:
ret = opal_error_code(ret);
}
out:
mutex_unlock(&psr_mutex);
out_token:
opal_async_release_token(token);
return ret;
}
static ssize_t psr_store(struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t count)
{
struct psr_attr *psr_attr = container_of(attr, struct psr_attr, attr);
struct opal_msg msg;
int psr, ret, token;
ret = kstrtoint(buf, 0, &psr);
if (ret)
return ret;
token = opal_async_get_token_interruptible();
if (token < 0) {
pr_devel("Failed to get token\n");
return token;
}
ret = mutex_lock_interruptible(&psr_mutex);
if (ret)
goto out_token;
ret = opal_set_power_shift_ratio(psr_attr->handle, token, psr);
switch (ret) {
case OPAL_ASYNC_COMPLETION:
ret = opal_async_wait_response(token, &msg);
if (ret) {
pr_devel("Failed to wait for the async response\n");
ret = -EIO;
goto out;
}
ret = opal_error_code(opal_get_async_rc(msg));
if (!ret)
ret = count;
break;
case OPAL_SUCCESS:
ret = count;
break;
default:
ret = opal_error_code(ret);
}
out:
mutex_unlock(&psr_mutex);
out_token:
opal_async_release_token(token);
return ret;
}
void __init opal_psr_init(void)
{
struct device_node *psr, *node;
int i = 0;
psr = of_find_compatible_node(NULL, NULL,
"ibm,opal-power-shift-ratio");
if (!psr) {
pr_devel("Power-shift-ratio node not found\n");
return;
}
psr_attrs = kcalloc(of_get_child_count(psr), sizeof(*psr_attrs),
GFP_KERNEL);
if (!psr_attrs)
return;
psr_kobj = kobject_create_and_add("psr", opal_kobj);
if (!psr_kobj) {
pr_warn("Failed to create psr kobject\n");
goto out;
}
for_each_child_of_node(psr, node) {
if (of_property_read_u32(node, "handle",
&psr_attrs[i].handle))
goto out_kobj;
sysfs_attr_init(&psr_attrs[i].attr.attr);
if (of_property_read_string(node, "label",
&psr_attrs[i].attr.attr.name))
goto out_kobj;
psr_attrs[i].attr.attr.mode = 0664;
psr_attrs[i].attr.show = psr_show;
psr_attrs[i].attr.store = psr_store;
if (sysfs_create_file(psr_kobj, &psr_attrs[i].attr.attr)) {
pr_devel("Failed to create psr sysfs file %s\n",
psr_attrs[i].attr.attr.name);
goto out_kobj;
}
i++;
}
return;
out_kobj:
kobject_put(psr_kobj);
out:
kfree(psr_attrs);
}
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