![Pierre-Louis Bossart](/assets/img/avatar_default.png)
Waiting for the enumeration to be complete may not be enough for a Slave driver, there is a possible race condition between resume operations and initializations handled in an interrupt thread, which can results in settings not being fully restored after system or pm_runtime resume. This patch builds on the changes added for enumeration_complete, init_completion() is called when the Slave device becomes UNATTACHED, as done with enumeration_complete. The difference with the enumeration_complete case is that complete() is signaled after the Slave device is fully initialized after the .update_status() callback is called. A Slave device driver can decide to wait on either of the two complete() cases, depending on its initialization code and requirements. Signed-off-by: Rander Wang <rander.wang@linux.intel.com> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Link: https://lore.kernel.org/r/20200115000844.14695-4-pierre-louis.bossart@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
229 lines
5.3 KiB
C
229 lines
5.3 KiB
C
// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
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// Copyright(c) 2015-17 Intel Corporation.
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#include <linux/acpi.h>
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#include <linux/of.h>
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#include <linux/soundwire/sdw.h>
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#include <linux/soundwire/sdw_type.h>
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#include "bus.h"
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static void sdw_slave_release(struct device *dev)
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{
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struct sdw_slave *slave = dev_to_sdw_dev(dev);
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kfree(slave);
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}
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static int sdw_slave_add(struct sdw_bus *bus,
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struct sdw_slave_id *id, struct fwnode_handle *fwnode)
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{
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struct sdw_slave *slave;
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int ret;
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slave = kzalloc(sizeof(*slave), GFP_KERNEL);
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if (!slave)
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return -ENOMEM;
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/* Initialize data structure */
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memcpy(&slave->id, id, sizeof(*id));
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slave->dev.parent = bus->dev;
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slave->dev.fwnode = fwnode;
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if (id->unique_id == SDW_IGNORED_UNIQUE_ID) {
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/* name shall be sdw:link:mfg:part:class */
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dev_set_name(&slave->dev, "sdw:%x:%x:%x:%x",
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bus->link_id, id->mfg_id, id->part_id,
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id->class_id);
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} else {
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/* name shall be sdw:link:mfg:part:class:unique */
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dev_set_name(&slave->dev, "sdw:%x:%x:%x:%x:%x",
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bus->link_id, id->mfg_id, id->part_id,
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id->class_id, id->unique_id);
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}
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slave->dev.release = sdw_slave_release;
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slave->dev.bus = &sdw_bus_type;
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slave->dev.of_node = of_node_get(to_of_node(fwnode));
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slave->bus = bus;
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slave->status = SDW_SLAVE_UNATTACHED;
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init_completion(&slave->enumeration_complete);
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init_completion(&slave->initialization_complete);
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slave->dev_num = 0;
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init_completion(&slave->probe_complete);
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slave->probed = false;
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mutex_lock(&bus->bus_lock);
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list_add_tail(&slave->node, &bus->slaves);
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mutex_unlock(&bus->bus_lock);
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ret = device_register(&slave->dev);
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if (ret) {
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dev_err(bus->dev, "Failed to add slave: ret %d\n", ret);
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/*
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* On err, don't free but drop ref as this will be freed
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* when release method is invoked.
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*/
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mutex_lock(&bus->bus_lock);
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list_del(&slave->node);
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mutex_unlock(&bus->bus_lock);
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put_device(&slave->dev);
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}
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sdw_slave_debugfs_init(slave);
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return ret;
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}
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#if IS_ENABLED(CONFIG_ACPI)
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static bool find_slave(struct sdw_bus *bus,
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struct acpi_device *adev,
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struct sdw_slave_id *id)
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{
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unsigned long long addr;
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unsigned int link_id;
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acpi_status status;
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status = acpi_evaluate_integer(adev->handle,
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METHOD_NAME__ADR, NULL, &addr);
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if (ACPI_FAILURE(status)) {
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dev_err(bus->dev, "_ADR resolution failed: %x\n",
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status);
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return false;
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}
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/* Extract link id from ADR, Bit 51 to 48 (included) */
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link_id = (addr >> 48) & GENMASK(3, 0);
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/* Check for link_id match */
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if (link_id != bus->link_id)
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return false;
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sdw_extract_slave_id(bus, addr, id);
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return true;
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}
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/*
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* sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node
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* @bus: SDW bus instance
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*
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* Scans Master ACPI node for SDW child Slave devices and registers it.
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*/
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int sdw_acpi_find_slaves(struct sdw_bus *bus)
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{
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struct acpi_device *adev, *parent;
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struct acpi_device *adev2, *parent2;
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parent = ACPI_COMPANION(bus->dev);
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if (!parent) {
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dev_err(bus->dev, "Can't find parent for acpi bind\n");
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return -ENODEV;
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}
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list_for_each_entry(adev, &parent->children, node) {
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struct sdw_slave_id id;
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struct sdw_slave_id id2;
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bool ignore_unique_id = true;
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if (!find_slave(bus, adev, &id))
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continue;
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/* brute-force O(N^2) search for duplicates */
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parent2 = parent;
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list_for_each_entry(adev2, &parent2->children, node) {
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if (adev == adev2)
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continue;
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if (!find_slave(bus, adev2, &id2))
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continue;
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if (id.sdw_version != id2.sdw_version ||
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id.mfg_id != id2.mfg_id ||
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id.part_id != id2.part_id ||
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id.class_id != id2.class_id)
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continue;
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if (id.unique_id != id2.unique_id) {
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dev_dbg(bus->dev,
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"Valid unique IDs %x %x for Slave mfg %x part %d\n",
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id.unique_id, id2.unique_id,
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id.mfg_id, id.part_id);
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ignore_unique_id = false;
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} else {
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dev_err(bus->dev,
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"Invalid unique IDs %x %x for Slave mfg %x part %d\n",
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id.unique_id, id2.unique_id,
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id.mfg_id, id.part_id);
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return -ENODEV;
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}
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}
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if (ignore_unique_id)
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id.unique_id = SDW_IGNORED_UNIQUE_ID;
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/*
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* don't error check for sdw_slave_add as we want to continue
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* adding Slaves
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*/
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sdw_slave_add(bus, &id, acpi_fwnode_handle(adev));
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}
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return 0;
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}
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#endif
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/*
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* sdw_of_find_slaves() - Find Slave devices in master device tree node
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* @bus: SDW bus instance
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*
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* Scans Master DT node for SDW child Slave devices and registers it.
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*/
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int sdw_of_find_slaves(struct sdw_bus *bus)
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{
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struct device *dev = bus->dev;
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struct device_node *node;
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for_each_child_of_node(bus->dev->of_node, node) {
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int link_id, ret, len;
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unsigned int sdw_version;
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const char *compat = NULL;
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struct sdw_slave_id id;
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const __be32 *addr;
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compat = of_get_property(node, "compatible", NULL);
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if (!compat)
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continue;
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ret = sscanf(compat, "sdw%01x%04hx%04hx%02hhx", &sdw_version,
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&id.mfg_id, &id.part_id, &id.class_id);
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if (ret != 4) {
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dev_err(dev, "Invalid compatible string found %s\n",
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compat);
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continue;
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}
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addr = of_get_property(node, "reg", &len);
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if (!addr || (len < 2 * sizeof(u32))) {
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dev_err(dev, "Invalid Link and Instance ID\n");
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continue;
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}
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link_id = be32_to_cpup(addr++);
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id.unique_id = be32_to_cpup(addr);
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id.sdw_version = sdw_version;
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/* Check for link_id match */
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if (link_id != bus->link_id)
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continue;
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sdw_slave_add(bus, &id, of_fwnode_handle(node));
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}
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return 0;
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}
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