diff options
Diffstat (limited to 'drivers/thunderbolt/domain.c')
| -rw-r--r-- | drivers/thunderbolt/domain.c | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/drivers/thunderbolt/domain.c b/drivers/thunderbolt/domain.c new file mode 100644 index 000000000000..3302f4c59638 --- /dev/null +++ b/drivers/thunderbolt/domain.c @@ -0,0 +1,230 @@ +/* + * Thunderbolt bus support + * + * Copyright (C) 2017, Intel Corporation + * Author: Mika Westerberg <mika.westerberg@linux.intel.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/device.h> +#include <linux/idr.h> +#include <linux/module.h> +#include <linux/slab.h> + +#include "tb.h" + +static DEFINE_IDA(tb_domain_ida); + +struct bus_type tb_bus_type = { + .name = "thunderbolt", +}; + +static void tb_domain_release(struct device *dev) +{ + struct tb *tb = container_of(dev, struct tb, dev); + + tb_ctl_free(tb->ctl); + destroy_workqueue(tb->wq); + ida_simple_remove(&tb_domain_ida, tb->index); + mutex_destroy(&tb->lock); + kfree(tb); +} + +struct device_type tb_domain_type = { + .name = "thunderbolt_domain", + .release = tb_domain_release, +}; + +/** + * tb_domain_alloc() - Allocate a domain + * @nhi: Pointer to the host controller + * @privsize: Size of the connection manager private data + * + * Allocates and initializes a new Thunderbolt domain. Connection + * managers are expected to call this and then fill in @cm_ops + * accordingly. + * + * Call tb_domain_put() to release the domain before it has been added + * to the system. + * + * Return: allocated domain structure on %NULL in case of error + */ +struct tb *tb_domain_alloc(struct tb_nhi *nhi, size_t privsize) +{ + struct tb *tb; + + /* + * Make sure the structure sizes map with that the hardware + * expects because bit-fields are being used. + */ + BUILD_BUG_ON(sizeof(struct tb_regs_switch_header) != 5 * 4); + BUILD_BUG_ON(sizeof(struct tb_regs_port_header) != 8 * 4); + BUILD_BUG_ON(sizeof(struct tb_regs_hop) != 2 * 4); + + tb = kzalloc(sizeof(*tb) + privsize, GFP_KERNEL); + if (!tb) + return NULL; + + tb->nhi = nhi; + mutex_init(&tb->lock); + + tb->index = ida_simple_get(&tb_domain_ida, 0, 0, GFP_KERNEL); + if (tb->index < 0) + goto err_free; + + tb->wq = alloc_ordered_workqueue("thunderbolt%d", 0, tb->index); + if (!tb->wq) + goto err_remove_ida; + + tb->dev.parent = &nhi->pdev->dev; + tb->dev.bus = &tb_bus_type; + tb->dev.type = &tb_domain_type; + dev_set_name(&tb->dev, "domain%d", tb->index); + device_initialize(&tb->dev); + + return tb; + +err_remove_ida: + ida_simple_remove(&tb_domain_ida, tb->index); +err_free: + kfree(tb); + + return NULL; +} + +/** + * tb_domain_add() - Add domain to the system + * @tb: Domain to add + * + * Starts the domain and adds it to the system. Hotplugging devices will + * work after this has been returned successfully. In order to remove + * and release the domain after this function has been called, call + * tb_domain_remove(). + * + * Return: %0 in case of success and negative errno in case of error + */ +int tb_domain_add(struct tb *tb) +{ + int ret; + + if (WARN_ON(!tb->cm_ops)) + return -EINVAL; + + mutex_lock(&tb->lock); + + tb->ctl = tb_ctl_alloc(tb->nhi, tb->cm_ops->hotplug, tb); + if (!tb->ctl) { + ret = -ENOMEM; + goto err_unlock; + } + + /* + * tb_schedule_hotplug_handler may be called as soon as the config + * channel is started. Thats why we have to hold the lock here. + */ + tb_ctl_start(tb->ctl); + + ret = device_add(&tb->dev); + if (ret) + goto err_ctl_stop; + + /* Start the domain */ + if (tb->cm_ops->start) { + ret = tb->cm_ops->start(tb); + if (ret) + goto err_domain_del; + } + + /* This starts event processing */ + mutex_unlock(&tb->lock); + + return 0; + +err_domain_del: + device_del(&tb->dev); +err_ctl_stop: + tb_ctl_stop(tb->ctl); +err_unlock: + mutex_unlock(&tb->lock); + + return ret; +} + +/** + * tb_domain_remove() - Removes and releases a domain + * @tb: Domain to remove + * + * Stops the domain, removes it from the system and releases all + * resources once the last reference has been released. + */ +void tb_domain_remove(struct tb *tb) +{ + mutex_lock(&tb->lock); + if (tb->cm_ops->stop) + tb->cm_ops->stop(tb); + /* Stop the domain control traffic */ + tb_ctl_stop(tb->ctl); + mutex_unlock(&tb->lock); + + flush_workqueue(tb->wq); + device_unregister(&tb->dev); +} + +/** + * tb_domain_suspend_noirq() - Suspend a domain + * @tb: Domain to suspend + * + * Suspends all devices in the domain and stops the control channel. + */ +int tb_domain_suspend_noirq(struct tb *tb) +{ + int ret = 0; + + /* + * The control channel interrupt is left enabled during suspend + * and taking the lock here prevents any events happening before + * we actually have stopped the domain and the control channel. + */ + mutex_lock(&tb->lock); + if (tb->cm_ops->suspend_noirq) + ret = tb->cm_ops->suspend_noirq(tb); + if (!ret) + tb_ctl_stop(tb->ctl); + mutex_unlock(&tb->lock); + + return ret; +} + +/** + * tb_domain_resume_noirq() - Resume a domain + * @tb: Domain to resume + * + * Re-starts the control channel, and resumes all devices connected to + * the domain. + */ +int tb_domain_resume_noirq(struct tb *tb) +{ + int ret = 0; + + mutex_lock(&tb->lock); + tb_ctl_start(tb->ctl); + if (tb->cm_ops->resume_noirq) + ret = tb->cm_ops->resume_noirq(tb); + mutex_unlock(&tb->lock); + + return ret; +} + +int tb_domain_init(void) +{ + return bus_register(&tb_bus_type); +} + +void tb_domain_exit(void) +{ + bus_unregister(&tb_bus_type); + ida_destroy(&tb_domain_ida); +} |