12874c5fdSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-or-later
28e84b2d1SShilpasri G Bhat /*
38e84b2d1SShilpasri G Bhat * PowerNV OPAL Power-Shift-Ratio interface
48e84b2d1SShilpasri G Bhat *
58e84b2d1SShilpasri G Bhat * Copyright 2017 IBM Corp.
68e84b2d1SShilpasri G Bhat */
78e84b2d1SShilpasri G Bhat
88e84b2d1SShilpasri G Bhat #define pr_fmt(fmt) "opal-psr: " fmt
98e84b2d1SShilpasri G Bhat
108e84b2d1SShilpasri G Bhat #include <linux/of.h>
118e84b2d1SShilpasri G Bhat #include <linux/kobject.h>
128e84b2d1SShilpasri G Bhat #include <linux/slab.h>
138e84b2d1SShilpasri G Bhat
148e84b2d1SShilpasri G Bhat #include <asm/opal.h>
158e84b2d1SShilpasri G Bhat
16bc75e543SYueHaibing static DEFINE_MUTEX(psr_mutex);
178e84b2d1SShilpasri G Bhat
188e84b2d1SShilpasri G Bhat static struct kobject *psr_kobj;
198e84b2d1SShilpasri G Bhat
20bc75e543SYueHaibing static struct psr_attr {
218e84b2d1SShilpasri G Bhat u32 handle;
228e84b2d1SShilpasri G Bhat struct kobj_attribute attr;
238e84b2d1SShilpasri G Bhat } *psr_attrs;
248e84b2d1SShilpasri G Bhat
psr_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)258e84b2d1SShilpasri G Bhat static ssize_t psr_show(struct kobject *kobj, struct kobj_attribute *attr,
268e84b2d1SShilpasri G Bhat char *buf)
278e84b2d1SShilpasri G Bhat {
288e84b2d1SShilpasri G Bhat struct psr_attr *psr_attr = container_of(attr, struct psr_attr, attr);
298e84b2d1SShilpasri G Bhat struct opal_msg msg;
308e84b2d1SShilpasri G Bhat int psr, ret, token;
318e84b2d1SShilpasri G Bhat
328e84b2d1SShilpasri G Bhat token = opal_async_get_token_interruptible();
338e84b2d1SShilpasri G Bhat if (token < 0) {
348e84b2d1SShilpasri G Bhat pr_devel("Failed to get token\n");
358e84b2d1SShilpasri G Bhat return token;
368e84b2d1SShilpasri G Bhat }
378e84b2d1SShilpasri G Bhat
388e84b2d1SShilpasri G Bhat ret = mutex_lock_interruptible(&psr_mutex);
398e84b2d1SShilpasri G Bhat if (ret)
408e84b2d1SShilpasri G Bhat goto out_token;
418e84b2d1SShilpasri G Bhat
428e84b2d1SShilpasri G Bhat ret = opal_get_power_shift_ratio(psr_attr->handle, token,
438e84b2d1SShilpasri G Bhat (u32 *)__pa(&psr));
448e84b2d1SShilpasri G Bhat switch (ret) {
458e84b2d1SShilpasri G Bhat case OPAL_ASYNC_COMPLETION:
468e84b2d1SShilpasri G Bhat ret = opal_async_wait_response(token, &msg);
478e84b2d1SShilpasri G Bhat if (ret) {
488e84b2d1SShilpasri G Bhat pr_devel("Failed to wait for the async response\n");
498e84b2d1SShilpasri G Bhat ret = -EIO;
508e84b2d1SShilpasri G Bhat goto out;
518e84b2d1SShilpasri G Bhat }
528e84b2d1SShilpasri G Bhat ret = opal_error_code(opal_get_async_rc(msg));
538e84b2d1SShilpasri G Bhat if (!ret) {
548e84b2d1SShilpasri G Bhat ret = sprintf(buf, "%u\n", be32_to_cpu(psr));
558e84b2d1SShilpasri G Bhat if (ret < 0)
568e84b2d1SShilpasri G Bhat ret = -EIO;
578e84b2d1SShilpasri G Bhat }
588e84b2d1SShilpasri G Bhat break;
598e84b2d1SShilpasri G Bhat case OPAL_SUCCESS:
608e84b2d1SShilpasri G Bhat ret = sprintf(buf, "%u\n", be32_to_cpu(psr));
618e84b2d1SShilpasri G Bhat if (ret < 0)
628e84b2d1SShilpasri G Bhat ret = -EIO;
638e84b2d1SShilpasri G Bhat break;
648e84b2d1SShilpasri G Bhat default:
658e84b2d1SShilpasri G Bhat ret = opal_error_code(ret);
668e84b2d1SShilpasri G Bhat }
678e84b2d1SShilpasri G Bhat
688e84b2d1SShilpasri G Bhat out:
698e84b2d1SShilpasri G Bhat mutex_unlock(&psr_mutex);
708e84b2d1SShilpasri G Bhat out_token:
718e84b2d1SShilpasri G Bhat opal_async_release_token(token);
728e84b2d1SShilpasri G Bhat return ret;
738e84b2d1SShilpasri G Bhat }
748e84b2d1SShilpasri G Bhat
psr_store(struct kobject * kobj,struct kobj_attribute * attr,const char * buf,size_t count)758e84b2d1SShilpasri G Bhat static ssize_t psr_store(struct kobject *kobj, struct kobj_attribute *attr,
768e84b2d1SShilpasri G Bhat const char *buf, size_t count)
778e84b2d1SShilpasri G Bhat {
788e84b2d1SShilpasri G Bhat struct psr_attr *psr_attr = container_of(attr, struct psr_attr, attr);
798e84b2d1SShilpasri G Bhat struct opal_msg msg;
808e84b2d1SShilpasri G Bhat int psr, ret, token;
818e84b2d1SShilpasri G Bhat
828e84b2d1SShilpasri G Bhat ret = kstrtoint(buf, 0, &psr);
838e84b2d1SShilpasri G Bhat if (ret)
848e84b2d1SShilpasri G Bhat return ret;
858e84b2d1SShilpasri G Bhat
868e84b2d1SShilpasri G Bhat token = opal_async_get_token_interruptible();
878e84b2d1SShilpasri G Bhat if (token < 0) {
888e84b2d1SShilpasri G Bhat pr_devel("Failed to get token\n");
898e84b2d1SShilpasri G Bhat return token;
908e84b2d1SShilpasri G Bhat }
918e84b2d1SShilpasri G Bhat
928e84b2d1SShilpasri G Bhat ret = mutex_lock_interruptible(&psr_mutex);
938e84b2d1SShilpasri G Bhat if (ret)
948e84b2d1SShilpasri G Bhat goto out_token;
958e84b2d1SShilpasri G Bhat
968e84b2d1SShilpasri G Bhat ret = opal_set_power_shift_ratio(psr_attr->handle, token, psr);
978e84b2d1SShilpasri G Bhat switch (ret) {
988e84b2d1SShilpasri G Bhat case OPAL_ASYNC_COMPLETION:
998e84b2d1SShilpasri G Bhat ret = opal_async_wait_response(token, &msg);
1008e84b2d1SShilpasri G Bhat if (ret) {
1018e84b2d1SShilpasri G Bhat pr_devel("Failed to wait for the async response\n");
1028e84b2d1SShilpasri G Bhat ret = -EIO;
1038e84b2d1SShilpasri G Bhat goto out;
1048e84b2d1SShilpasri G Bhat }
1058e84b2d1SShilpasri G Bhat ret = opal_error_code(opal_get_async_rc(msg));
1068e84b2d1SShilpasri G Bhat if (!ret)
1078e84b2d1SShilpasri G Bhat ret = count;
1088e84b2d1SShilpasri G Bhat break;
1098e84b2d1SShilpasri G Bhat case OPAL_SUCCESS:
1108e84b2d1SShilpasri G Bhat ret = count;
1118e84b2d1SShilpasri G Bhat break;
1128e84b2d1SShilpasri G Bhat default:
1138e84b2d1SShilpasri G Bhat ret = opal_error_code(ret);
1148e84b2d1SShilpasri G Bhat }
1158e84b2d1SShilpasri G Bhat
1168e84b2d1SShilpasri G Bhat out:
1178e84b2d1SShilpasri G Bhat mutex_unlock(&psr_mutex);
1188e84b2d1SShilpasri G Bhat out_token:
1198e84b2d1SShilpasri G Bhat opal_async_release_token(token);
1208e84b2d1SShilpasri G Bhat return ret;
1218e84b2d1SShilpasri G Bhat }
1228e84b2d1SShilpasri G Bhat
opal_psr_init(void)1238e84b2d1SShilpasri G Bhat void __init opal_psr_init(void)
1248e84b2d1SShilpasri G Bhat {
1258e84b2d1SShilpasri G Bhat struct device_node *psr, *node;
1268e84b2d1SShilpasri G Bhat int i = 0;
1278e84b2d1SShilpasri G Bhat
1288e84b2d1SShilpasri G Bhat psr = of_find_compatible_node(NULL, NULL,
1298e84b2d1SShilpasri G Bhat "ibm,opal-power-shift-ratio");
1308e84b2d1SShilpasri G Bhat if (!psr) {
1318e84b2d1SShilpasri G Bhat pr_devel("Power-shift-ratio node not found\n");
1328e84b2d1SShilpasri G Bhat return;
1338e84b2d1SShilpasri G Bhat }
1348e84b2d1SShilpasri G Bhat
135a0828cf5SMarkus Elfring psr_attrs = kcalloc(of_get_child_count(psr), sizeof(*psr_attrs),
1368e84b2d1SShilpasri G Bhat GFP_KERNEL);
1378e84b2d1SShilpasri G Bhat if (!psr_attrs)
138*605c27f3SLiang He goto out_put_psr;
1398e84b2d1SShilpasri G Bhat
1408e84b2d1SShilpasri G Bhat psr_kobj = kobject_create_and_add("psr", opal_kobj);
1418e84b2d1SShilpasri G Bhat if (!psr_kobj) {
1428e84b2d1SShilpasri G Bhat pr_warn("Failed to create psr kobject\n");
1438e84b2d1SShilpasri G Bhat goto out;
1448e84b2d1SShilpasri G Bhat }
1458e84b2d1SShilpasri G Bhat
1468e84b2d1SShilpasri G Bhat for_each_child_of_node(psr, node) {
1478e84b2d1SShilpasri G Bhat if (of_property_read_u32(node, "handle",
1488e84b2d1SShilpasri G Bhat &psr_attrs[i].handle))
1498e84b2d1SShilpasri G Bhat goto out_kobj;
1508e84b2d1SShilpasri G Bhat
1518e84b2d1SShilpasri G Bhat sysfs_attr_init(&psr_attrs[i].attr.attr);
1528e84b2d1SShilpasri G Bhat if (of_property_read_string(node, "label",
1538e84b2d1SShilpasri G Bhat &psr_attrs[i].attr.attr.name))
1548e84b2d1SShilpasri G Bhat goto out_kobj;
1558e84b2d1SShilpasri G Bhat psr_attrs[i].attr.attr.mode = 0664;
1568e84b2d1SShilpasri G Bhat psr_attrs[i].attr.show = psr_show;
1578e84b2d1SShilpasri G Bhat psr_attrs[i].attr.store = psr_store;
1588e84b2d1SShilpasri G Bhat if (sysfs_create_file(psr_kobj, &psr_attrs[i].attr.attr)) {
1598e84b2d1SShilpasri G Bhat pr_devel("Failed to create psr sysfs file %s\n",
1608e84b2d1SShilpasri G Bhat psr_attrs[i].attr.attr.name);
1618e84b2d1SShilpasri G Bhat goto out_kobj;
1628e84b2d1SShilpasri G Bhat }
1638e84b2d1SShilpasri G Bhat i++;
1648e84b2d1SShilpasri G Bhat }
165*605c27f3SLiang He of_node_put(psr);
1668e84b2d1SShilpasri G Bhat
1678e84b2d1SShilpasri G Bhat return;
1688e84b2d1SShilpasri G Bhat out_kobj:
169*605c27f3SLiang He of_node_put(node);
1708e84b2d1SShilpasri G Bhat kobject_put(psr_kobj);
1718e84b2d1SShilpasri G Bhat out:
1728e84b2d1SShilpasri G Bhat kfree(psr_attrs);
173*605c27f3SLiang He out_put_psr:
174*605c27f3SLiang He of_node_put(psr);
1758e84b2d1SShilpasri G Bhat }
176