diff options
Diffstat (limited to 'arch/powerpc/platforms/powernv/opal-psr.c')
| -rw-r--r-- | arch/powerpc/platforms/powernv/opal-psr.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/opal-psr.c b/arch/powerpc/platforms/powernv/opal-psr.c new file mode 100644 index 000000000..69d7e7595 --- /dev/null +++ b/arch/powerpc/platforms/powernv/opal-psr.c @@ -0,0 +1,171 @@ +// 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); +} |