--- /dev/null
+/*
+ * PowerNV OPAL Power-Shift-Ratio interface
+ *
+ * Copyright 2017 IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#define pr_fmt(fmt) "opal-psr: " fmt
+
+#include <linux/of.h>
+#include <linux/kobject.h>
+#include <linux/slab.h>
+
+#include <asm/opal.h>
+
+DEFINE_MUTEX(psr_mutex);
+
+static struct kobject *psr_kobj;
+
+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(struct psr_attr),
+ 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);
+}
projects / mirror_ubuntu-bionic-kernel.git / commitdiff