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295 lines
6.4 KiB
295 lines
6.4 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* System Control and Management Interface (SCMI) Message Protocol bus layer |
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* |
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* Copyright (C) 2018-2021 ARM Ltd. |
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*/ |
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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#include <linux/types.h> |
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#include <linux/module.h> |
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#include <linux/kernel.h> |
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#include <linux/slab.h> |
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#include <linux/device.h> |
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#include "common.h" |
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static DEFINE_IDA(scmi_bus_id); |
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static DEFINE_IDR(scmi_protocols); |
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static DEFINE_SPINLOCK(protocol_lock); |
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static const struct scmi_device_id * |
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scmi_dev_match_id(struct scmi_device *scmi_dev, struct scmi_driver *scmi_drv) |
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{ |
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const struct scmi_device_id *id = scmi_drv->id_table; |
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if (!id) |
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return NULL; |
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for (; id->protocol_id; id++) |
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if (id->protocol_id == scmi_dev->protocol_id) { |
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if (!id->name) |
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return id; |
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else if (!strcmp(id->name, scmi_dev->name)) |
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return id; |
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} |
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return NULL; |
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} |
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static int scmi_dev_match(struct device *dev, struct device_driver *drv) |
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{ |
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struct scmi_driver *scmi_drv = to_scmi_driver(drv); |
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struct scmi_device *scmi_dev = to_scmi_dev(dev); |
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const struct scmi_device_id *id; |
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id = scmi_dev_match_id(scmi_dev, scmi_drv); |
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if (id) |
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return 1; |
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return 0; |
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} |
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static int scmi_match_by_id_table(struct device *dev, void *data) |
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{ |
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struct scmi_device *sdev = to_scmi_dev(dev); |
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struct scmi_device_id *id_table = data; |
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return sdev->protocol_id == id_table->protocol_id && |
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!strcmp(sdev->name, id_table->name); |
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} |
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struct scmi_device *scmi_child_dev_find(struct device *parent, |
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int prot_id, const char *name) |
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{ |
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struct scmi_device_id id_table; |
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struct device *dev; |
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id_table.protocol_id = prot_id; |
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id_table.name = name; |
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dev = device_find_child(parent, &id_table, scmi_match_by_id_table); |
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if (!dev) |
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return NULL; |
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return to_scmi_dev(dev); |
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} |
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const struct scmi_protocol *scmi_protocol_get(int protocol_id) |
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{ |
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const struct scmi_protocol *proto; |
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proto = idr_find(&scmi_protocols, protocol_id); |
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if (!proto || !try_module_get(proto->owner)) { |
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pr_warn("SCMI Protocol 0x%x not found!\n", protocol_id); |
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return NULL; |
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} |
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pr_debug("Found SCMI Protocol 0x%x\n", protocol_id); |
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return proto; |
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} |
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void scmi_protocol_put(int protocol_id) |
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{ |
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const struct scmi_protocol *proto; |
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proto = idr_find(&scmi_protocols, protocol_id); |
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if (proto) |
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module_put(proto->owner); |
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} |
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static int scmi_dev_probe(struct device *dev) |
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{ |
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struct scmi_driver *scmi_drv = to_scmi_driver(dev->driver); |
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struct scmi_device *scmi_dev = to_scmi_dev(dev); |
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if (!scmi_dev->handle) |
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return -EPROBE_DEFER; |
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return scmi_drv->probe(scmi_dev); |
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} |
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static void scmi_dev_remove(struct device *dev) |
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{ |
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struct scmi_driver *scmi_drv = to_scmi_driver(dev->driver); |
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struct scmi_device *scmi_dev = to_scmi_dev(dev); |
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if (scmi_drv->remove) |
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scmi_drv->remove(scmi_dev); |
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} |
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static struct bus_type scmi_bus_type = { |
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.name = "scmi_protocol", |
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.match = scmi_dev_match, |
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.probe = scmi_dev_probe, |
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.remove = scmi_dev_remove, |
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}; |
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int scmi_driver_register(struct scmi_driver *driver, struct module *owner, |
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const char *mod_name) |
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{ |
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int retval; |
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if (!driver->probe) |
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return -EINVAL; |
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retval = scmi_protocol_device_request(driver->id_table); |
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if (retval) |
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return retval; |
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driver->driver.bus = &scmi_bus_type; |
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driver->driver.name = driver->name; |
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driver->driver.owner = owner; |
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driver->driver.mod_name = mod_name; |
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retval = driver_register(&driver->driver); |
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if (!retval) |
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pr_debug("registered new scmi driver %s\n", driver->name); |
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return retval; |
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} |
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EXPORT_SYMBOL_GPL(scmi_driver_register); |
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void scmi_driver_unregister(struct scmi_driver *driver) |
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{ |
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driver_unregister(&driver->driver); |
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scmi_protocol_device_unrequest(driver->id_table); |
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} |
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EXPORT_SYMBOL_GPL(scmi_driver_unregister); |
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static void scmi_device_release(struct device *dev) |
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{ |
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kfree(to_scmi_dev(dev)); |
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} |
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struct scmi_device * |
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scmi_device_create(struct device_node *np, struct device *parent, int protocol, |
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const char *name) |
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{ |
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int id, retval; |
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struct scmi_device *scmi_dev; |
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scmi_dev = kzalloc(sizeof(*scmi_dev), GFP_KERNEL); |
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if (!scmi_dev) |
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return NULL; |
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scmi_dev->name = kstrdup_const(name ?: "unknown", GFP_KERNEL); |
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if (!scmi_dev->name) { |
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kfree(scmi_dev); |
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return NULL; |
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} |
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id = ida_simple_get(&scmi_bus_id, 1, 0, GFP_KERNEL); |
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if (id < 0) { |
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kfree_const(scmi_dev->name); |
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kfree(scmi_dev); |
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return NULL; |
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} |
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scmi_dev->id = id; |
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scmi_dev->protocol_id = protocol; |
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scmi_dev->dev.parent = parent; |
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scmi_dev->dev.of_node = np; |
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scmi_dev->dev.bus = &scmi_bus_type; |
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scmi_dev->dev.release = scmi_device_release; |
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dev_set_name(&scmi_dev->dev, "scmi_dev.%d", id); |
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retval = device_register(&scmi_dev->dev); |
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if (retval) |
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goto put_dev; |
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return scmi_dev; |
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put_dev: |
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kfree_const(scmi_dev->name); |
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put_device(&scmi_dev->dev); |
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ida_simple_remove(&scmi_bus_id, id); |
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return NULL; |
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} |
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void scmi_device_destroy(struct scmi_device *scmi_dev) |
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{ |
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kfree_const(scmi_dev->name); |
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scmi_handle_put(scmi_dev->handle); |
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ida_simple_remove(&scmi_bus_id, scmi_dev->id); |
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device_unregister(&scmi_dev->dev); |
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} |
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void scmi_set_handle(struct scmi_device *scmi_dev) |
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{ |
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scmi_dev->handle = scmi_handle_get(&scmi_dev->dev); |
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} |
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int scmi_protocol_register(const struct scmi_protocol *proto) |
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{ |
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int ret; |
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if (!proto) { |
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pr_err("invalid protocol\n"); |
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return -EINVAL; |
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} |
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if (!proto->instance_init) { |
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pr_err("missing init for protocol 0x%x\n", proto->id); |
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return -EINVAL; |
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} |
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spin_lock(&protocol_lock); |
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ret = idr_alloc(&scmi_protocols, (void *)proto, |
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proto->id, proto->id + 1, GFP_ATOMIC); |
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spin_unlock(&protocol_lock); |
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if (ret != proto->id) { |
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pr_err("unable to allocate SCMI idr slot for 0x%x - err %d\n", |
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proto->id, ret); |
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return ret; |
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} |
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pr_debug("Registered SCMI Protocol 0x%x\n", proto->id); |
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return 0; |
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} |
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EXPORT_SYMBOL_GPL(scmi_protocol_register); |
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void scmi_protocol_unregister(const struct scmi_protocol *proto) |
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{ |
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spin_lock(&protocol_lock); |
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idr_remove(&scmi_protocols, proto->id); |
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spin_unlock(&protocol_lock); |
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pr_debug("Unregistered SCMI Protocol 0x%x\n", proto->id); |
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return; |
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} |
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EXPORT_SYMBOL_GPL(scmi_protocol_unregister); |
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static int __scmi_devices_unregister(struct device *dev, void *data) |
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{ |
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struct scmi_device *scmi_dev = to_scmi_dev(dev); |
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scmi_device_destroy(scmi_dev); |
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return 0; |
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} |
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static void scmi_devices_unregister(void) |
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{ |
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bus_for_each_dev(&scmi_bus_type, NULL, NULL, __scmi_devices_unregister); |
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} |
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int __init scmi_bus_init(void) |
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{ |
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int retval; |
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retval = bus_register(&scmi_bus_type); |
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if (retval) |
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pr_err("scmi protocol bus register failed (%d)\n", retval); |
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return retval; |
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} |
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void __exit scmi_bus_exit(void) |
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{ |
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scmi_devices_unregister(); |
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bus_unregister(&scmi_bus_type); |
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ida_destroy(&scmi_bus_id); |
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}
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