| /* |
| * Google LWIS Top Level Device Driver |
| * |
| * Copyright (c) 2018 Google, LLC |
| * |
| * 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. |
| */ |
| |
| #define pr_fmt(fmt) KBUILD_MODNAME "-top-dev: " fmt |
| |
| #include "lwis_device_top.h" |
| #include "lwis_event.h" |
| #include "lwis_init.h" |
| |
| #include <linux/device.h> |
| #include <linux/init.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/platform_device.h> |
| #include <linux/slab.h> |
| |
| #ifdef CONFIG_OF |
| #include "lwis_dt.h" |
| #endif |
| |
| #define LWIS_DRIVER_NAME "lwis-top" |
| |
| static int lwis_top_register_io(struct lwis_device *lwis_dev, struct lwis_io_entry *entry, |
| int access_size); |
| static int lwis_top_close(struct lwis_device *lwis_dev); |
| static struct lwis_device_subclass_operations top_vops = { |
| .register_io = lwis_top_register_io, |
| .register_io_barrier = NULL, |
| .device_enable = NULL, |
| .device_disable = NULL, |
| .event_enable = NULL, |
| .event_flags_updated = NULL, |
| .close = lwis_top_close, |
| }; |
| |
| static int lwis_top_event_subscribe(struct lwis_device *lwis_dev, int64_t trigger_event_id, |
| int trigger_device_id, int receiver_device_id); |
| static int lwis_top_event_unsubscribe(struct lwis_device *lwis_dev, int64_t trigger_event_id, |
| int receiver_device_id); |
| static void lwis_top_event_notify(struct lwis_device *lwis_dev, int64_t trigger_event_id, |
| int64_t trigger_event_count, int64_t trigger_event_timestamp, |
| bool in_irq); |
| static void lwis_top_event_subscribe_release(struct lwis_device *lwis_dev); |
| static struct lwis_event_subscribe_operations top_subscribe_ops = { |
| .subscribe_event = lwis_top_event_subscribe, |
| .unsubscribe_event = lwis_top_event_unsubscribe, |
| .notify_event_subscriber = lwis_top_event_notify, |
| .release = lwis_top_event_subscribe_release, |
| }; |
| |
| struct lwis_event_subscribe_info { |
| /* Subscribed Event ID */ |
| int64_t event_id; |
| /* LWIS device who subscribed an event */ |
| struct lwis_device *receiver_dev; |
| /* LWIS device who will trigger an event */ |
| struct lwis_device *trigger_dev; |
| /* Node in the lwis_top_device->event_subscribe hash table */ |
| struct hlist_node node; |
| }; |
| |
| struct lwis_trigger_event_info { |
| /* Store emitted event id from trigger device */ |
| int64_t trigger_event_id; |
| /* Store emitted event count from trigger device */ |
| int64_t trigger_event_count; |
| /* Store emitted event timestamp from trigger device */ |
| int64_t trigger_event_timestamp; |
| /* node of list head */ |
| struct list_head node; |
| }; |
| |
| static void subscribe_tasklet_func(unsigned long data) |
| { |
| struct lwis_top_device *lwis_top_dev = (struct lwis_top_device *)data; |
| struct lwis_trigger_event_info *trigger_event; |
| struct lwis_event_subscribe_info *p; |
| struct list_head *it_sub, *it_sub_tmp; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&lwis_top_dev->base_dev.lock, flags); |
| list_for_each_safe (it_sub, it_sub_tmp, &lwis_top_dev->emitted_event_list_tasklet) { |
| trigger_event = list_entry(it_sub, struct lwis_trigger_event_info, node); |
| list_del(&trigger_event->node); |
| hash_for_each_possible (lwis_top_dev->event_subscriber, p, node, |
| trigger_event->trigger_event_id) { |
| if (p->event_id == trigger_event->trigger_event_id) { |
| /* Notify subscriber an event is happening */ |
| lwis_device_external_event_emit( |
| p->receiver_dev, trigger_event->trigger_event_id, |
| trigger_event->trigger_event_count, |
| trigger_event->trigger_event_timestamp, false); |
| } |
| } |
| kfree(trigger_event); |
| } |
| spin_unlock_irqrestore(&lwis_top_dev->base_dev.lock, flags); |
| } |
| |
| static void lwis_top_event_notify(struct lwis_device *lwis_dev, int64_t trigger_event_id, |
| int64_t trigger_event_count, int64_t trigger_event_timestamp, |
| bool in_irq) |
| { |
| struct lwis_top_device *lwis_top_dev = (struct lwis_top_device *)lwis_dev; |
| unsigned long flags; |
| |
| struct lwis_trigger_event_info *trigger_event = |
| kmalloc(sizeof(struct lwis_trigger_event_info), GFP_ATOMIC); |
| if (trigger_event == NULL) { |
| dev_err(lwis_top_dev->base_dev.dev, "Allocate trigger_event_info failed"); |
| return; |
| } |
| |
| trigger_event->trigger_event_id = trigger_event_id; |
| trigger_event->trigger_event_count = trigger_event_count; |
| trigger_event->trigger_event_timestamp = trigger_event_timestamp; |
| spin_lock_irqsave(&lwis_top_dev->base_dev.lock, flags); |
| list_add_tail(&trigger_event->node, &lwis_top_dev->emitted_event_list_tasklet); |
| spin_unlock_irqrestore(&lwis_top_dev->base_dev.lock, flags); |
| /* Schedule deferred subscribed events */ |
| tasklet_schedule(&lwis_top_dev->subscribe_tasklet); |
| } |
| |
| static int lwis_top_event_unsubscribe(struct lwis_device *lwis_dev, int64_t trigger_event_id, |
| int receiver_device_id) |
| { |
| struct lwis_top_device *lwis_top_dev = (struct lwis_top_device *)lwis_dev; |
| struct lwis_device *trigger_dev = NULL; |
| struct lwis_event_subscribe_info *p = NULL; |
| struct hlist_node *tmp = NULL; |
| struct lwis_trigger_event_info *pending_event, *n; |
| unsigned long flags; |
| bool has_subscriber = false; |
| |
| spin_lock_irqsave(&lwis_top_dev->base_dev.lock, flags); |
| |
| /* Remove event from hash table */ |
| hash_for_each_possible_safe (lwis_top_dev->event_subscriber, p, tmp, node, |
| trigger_event_id) { |
| /* Clear pending events */ |
| list_for_each_entry_safe (pending_event, n, |
| &lwis_top_dev->emitted_event_list_tasklet, node) { |
| /* The condition indicates that clear pending events by subscriber |
| * because there are possibly other subscribers have the same pending event. |
| */ |
| if (p->receiver_dev->id == receiver_device_id && |
| pending_event->trigger_event_id == trigger_event_id) { |
| list_del(&pending_event->node); |
| kfree(pending_event); |
| } |
| } |
| |
| if (p->event_id == trigger_event_id && p->receiver_dev->id == receiver_device_id) { |
| dev_info(lwis_dev->dev, |
| "unsubscribe event: %llx, trigger device: %s, target device: %s\n", |
| trigger_event_id, p->trigger_dev->name, p->receiver_dev->name); |
| trigger_dev = p->trigger_dev; |
| hash_del(&p->node); |
| kfree(p); |
| } else if (p->event_id == trigger_event_id && |
| p->receiver_dev->id != receiver_device_id) { |
| /* The condition indicate there are other client still subscribe the event */ |
| trigger_dev = p->trigger_dev; |
| has_subscriber = true; |
| } |
| } |
| spin_unlock_irqrestore(&lwis_top_dev->base_dev.lock, flags); |
| lwis_device_event_update_subscriber(trigger_dev, trigger_event_id, has_subscriber); |
| return 0; |
| } |
| |
| static int lwis_top_event_subscribe(struct lwis_device *lwis_dev, int64_t trigger_event_id, |
| int trigger_device_id, int receiver_device_id) |
| { |
| struct lwis_top_device *lwis_top_dev = (struct lwis_top_device *)lwis_dev; |
| struct lwis_device *lwis_trigger_dev = lwis_find_dev_by_id(trigger_device_id); |
| struct lwis_device *lwis_receiver_dev = lwis_find_dev_by_id(receiver_device_id); |
| struct lwis_event_subscribe_info *p, *new_subscription; |
| unsigned long flags; |
| int ret = 0; |
| bool has_subscriber = true; |
| |
| if (lwis_trigger_dev == NULL || lwis_receiver_dev == NULL) { |
| dev_err(lwis_top_dev->base_dev.dev, "LWIS trigger/receiver device not found"); |
| return -EINVAL; |
| } |
| spin_lock_irqsave(&lwis_top_dev->base_dev.lock, flags); |
| hash_for_each_possible (lwis_top_dev->event_subscriber, p, node, trigger_event_id) { |
| /* event already registered for this device */ |
| if (p->event_id == trigger_event_id && p->receiver_dev->id == receiver_device_id) { |
| spin_unlock_irqrestore(&lwis_top_dev->base_dev.lock, flags); |
| dev_info( |
| lwis_dev->dev, |
| "already registered event: %llx, trigger device: %s, target device: %s\n", |
| trigger_event_id, lwis_trigger_dev->name, lwis_receiver_dev->name); |
| goto out; |
| } |
| } |
| spin_unlock_irqrestore(&lwis_top_dev->base_dev.lock, flags); |
| |
| /* If the subscription does not exist in hash table, create one */ |
| new_subscription = kmalloc(sizeof(struct lwis_event_subscribe_info), GFP_KERNEL); |
| if (!new_subscription) { |
| dev_err(lwis_top_dev->base_dev.dev, |
| "Failed to allocate memory for new subscription\n"); |
| has_subscriber = false; |
| ret = -ENOMEM; |
| goto out; |
| } |
| new_subscription->event_id = trigger_event_id; |
| new_subscription->receiver_dev = lwis_receiver_dev; |
| new_subscription->trigger_dev = lwis_trigger_dev; |
| spin_lock_irqsave(&lwis_top_dev->base_dev.lock, flags); |
| hash_add(lwis_top_dev->event_subscriber, &new_subscription->node, trigger_event_id); |
| spin_unlock_irqrestore(&lwis_top_dev->base_dev.lock, flags); |
| dev_info(lwis_dev->dev, "subscribe event: %llx, trigger device: %s, target device: %s", |
| trigger_event_id, lwis_trigger_dev->name, lwis_receiver_dev->name); |
| |
| out: |
| ret = lwis_device_event_update_subscriber(lwis_trigger_dev, trigger_event_id, |
| has_subscriber); |
| if (ret < 0) { |
| dev_err(lwis_top_dev->base_dev.dev, "Failed to subcribe event : %llx\n", |
| trigger_event_id); |
| } |
| return ret; |
| } |
| |
| static void lwis_top_event_subscribe_init(struct lwis_top_device *lwis_top_dev) |
| { |
| hash_init(lwis_top_dev->event_subscriber); |
| INIT_LIST_HEAD(&lwis_top_dev->emitted_event_list_tasklet); |
| tasklet_init(&lwis_top_dev->subscribe_tasklet, subscribe_tasklet_func, |
| (unsigned long)lwis_top_dev); |
| } |
| |
| static void lwis_top_event_subscribe_clear(struct lwis_device *lwis_dev) |
| { |
| struct lwis_top_device *lwis_top_dev = (struct lwis_top_device *)lwis_dev; |
| struct lwis_event_subscribe_info *subscribe_info; |
| struct hlist_node *tmp; |
| struct lwis_trigger_event_info *pending_event, *n; |
| int i; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&lwis_top_dev->base_dev.lock, flags); |
| /* Clean up subscription table */ |
| hash_for_each_safe (lwis_top_dev->event_subscriber, i, tmp, subscribe_info, node) { |
| hash_del(&subscribe_info->node); |
| kfree(subscribe_info); |
| } |
| |
| /* Clean up emitted event list */ |
| list_for_each_entry_safe (pending_event, n, &lwis_top_dev->emitted_event_list_tasklet, |
| node) { |
| list_del(&pending_event->node); |
| kfree(pending_event); |
| } |
| spin_unlock_irqrestore(&lwis_top_dev->base_dev.lock, flags); |
| } |
| |
| static void lwis_top_event_subscribe_release(struct lwis_device *lwis_dev) |
| { |
| struct lwis_top_device *lwis_top_dev = (struct lwis_top_device *)lwis_dev; |
| lwis_top_event_subscribe_clear(lwis_dev); |
| /* Clean up tasklet process */ |
| tasklet_kill(&lwis_top_dev->subscribe_tasklet); |
| } |
| |
| static int lwis_top_register_io(struct lwis_device *lwis_dev, struct lwis_io_entry *entry, |
| int access_size) |
| { |
| struct lwis_top_device *top_dev = (struct lwis_top_device *)lwis_dev; |
| struct lwis_io_entry_rw_batch *rw_batch; |
| int i; |
| uint64_t reg_value; |
| |
| BUG_ON(!entry); |
| |
| if (entry->type == LWIS_IO_ENTRY_READ) { |
| if (entry->rw.offset >= SCRATCH_MEMORY_SIZE) { |
| dev_err(top_dev->base_dev.dev, "Offset (%llu) must be < %d\n", |
| entry->rw.offset, SCRATCH_MEMORY_SIZE); |
| return -EINVAL; |
| } |
| entry->rw.val = top_dev->scratch_mem[entry->rw.offset]; |
| } else if (entry->type == LWIS_IO_ENTRY_READ_BATCH) { |
| rw_batch = &entry->rw_batch; |
| if (rw_batch->offset > SCRATCH_MEMORY_SIZE || |
| SCRATCH_MEMORY_SIZE - rw_batch->offset < rw_batch->size_in_bytes) { |
| dev_err(top_dev->base_dev.dev, |
| "Read range[offset(%llu) + size_in_bytes(%zu)] exceeds scratch memory (%d)\n", |
| rw_batch->offset, rw_batch->size_in_bytes, SCRATCH_MEMORY_SIZE); |
| return -EINVAL; |
| } |
| for (i = 0; i < rw_batch->size_in_bytes; ++i) { |
| rw_batch->buf[i] = top_dev->scratch_mem[rw_batch->offset + i]; |
| } |
| } else if (entry->type == LWIS_IO_ENTRY_WRITE) { |
| if (entry->rw.offset >= SCRATCH_MEMORY_SIZE) { |
| dev_err(top_dev->base_dev.dev, "Offset (%llu) must be < %d\n", |
| entry->rw.offset, SCRATCH_MEMORY_SIZE); |
| return -EINVAL; |
| } |
| top_dev->scratch_mem[entry->rw.offset] = entry->rw.val; |
| } else if (entry->type == LWIS_IO_ENTRY_WRITE_BATCH) { |
| rw_batch = &entry->rw_batch; |
| if (rw_batch->offset > SCRATCH_MEMORY_SIZE || |
| SCRATCH_MEMORY_SIZE - rw_batch->offset < rw_batch->size_in_bytes) { |
| dev_err(top_dev->base_dev.dev, |
| "Write range[offset(%llu) + size_in_bytes(%zu)] exceeds scratch memory (%d)\n", |
| rw_batch->offset, rw_batch->size_in_bytes, SCRATCH_MEMORY_SIZE); |
| return -EINVAL; |
| } |
| for (i = 0; i < rw_batch->size_in_bytes; ++i) { |
| top_dev->scratch_mem[rw_batch->offset + i] = rw_batch->buf[i]; |
| } |
| } else if (entry->type == LWIS_IO_ENTRY_MODIFY) { |
| if (entry->mod.offset >= SCRATCH_MEMORY_SIZE) { |
| dev_err(top_dev->base_dev.dev, "Offset (%llu) must be < %d\n", |
| entry->mod.offset, SCRATCH_MEMORY_SIZE); |
| return -EINVAL; |
| } |
| reg_value = top_dev->scratch_mem[entry->mod.offset]; |
| reg_value &= ~entry->mod.val_mask; |
| reg_value |= entry->mod.val_mask & entry->mod.val; |
| top_dev->scratch_mem[entry->rw.offset] = reg_value; |
| } else { |
| dev_err(top_dev->base_dev.dev, "Invalid IO entry type: %d\n", entry->type); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static int lwis_top_close(struct lwis_device *lwis_dev) |
| { |
| lwis_top_event_subscribe_clear(lwis_dev); |
| return 0; |
| } |
| |
| static int lwis_top_device_setup(struct lwis_top_device *top_dev) |
| { |
| int ret = 0; |
| |
| #ifdef CONFIG_OF |
| /* Parse device tree for device configurations */ |
| ret = lwis_top_device_parse_dt(top_dev); |
| if (ret) { |
| dev_err(top_dev->base_dev.dev, "Failed to parse device tree\n"); |
| } |
| #else |
| /* Non-device-tree init: Save for future implementation */ |
| ret = -ENOSYS; |
| #endif |
| |
| return ret; |
| } |
| |
| static int lwis_top_device_probe(struct platform_device *plat_dev) |
| { |
| int ret = 0; |
| struct lwis_top_device *top_dev; |
| |
| /* Allocate top device specific data construct */ |
| top_dev = kzalloc(sizeof(struct lwis_top_device), GFP_KERNEL); |
| if (!top_dev) { |
| pr_err("Failed to allocate top device structure\n"); |
| return -ENOMEM; |
| } |
| |
| top_dev->base_dev.type = DEVICE_TYPE_TOP; |
| top_dev->base_dev.vops = top_vops; |
| top_dev->base_dev.subscribe_ops = top_subscribe_ops; |
| |
| /* Call the base device probe function */ |
| ret = lwis_base_probe((struct lwis_device *)top_dev, plat_dev); |
| if (ret) { |
| pr_err("Error in lwis base probe\n"); |
| goto error_probe; |
| } |
| |
| /* Call top device specific setup function */ |
| ret = lwis_top_device_setup(top_dev); |
| if (ret) { |
| dev_err(top_dev->base_dev.dev, "Error in top device initialization\n"); |
| lwis_base_unprobe((struct lwis_device *)top_dev); |
| goto error_probe; |
| } |
| |
| lwis_top_event_subscribe_init(top_dev); |
| |
| return 0; |
| |
| error_probe: |
| kfree(top_dev); |
| return ret; |
| } |
| |
| #ifdef CONFIG_OF |
| static const struct of_device_id lwis_id_match[] = { |
| { .compatible = LWIS_TOP_DEVICE_COMPAT }, |
| {}, |
| }; |
| // MODULE_DEVICE_TABLE(of, lwis_id_match); |
| |
| static struct platform_driver lwis_driver = { |
| .probe = lwis_top_device_probe, |
| .driver = { |
| .name = LWIS_DRIVER_NAME, |
| .owner = THIS_MODULE, |
| .of_match_table = lwis_id_match, |
| }, |
| }; |
| |
| #else /* CONFIG_OF not defined */ |
| static struct platform_device_id lwis_driver_id[] = { |
| { |
| .name = LWIS_DRIVER_NAME, |
| .driver_data = 0, |
| }, |
| {}, |
| }; |
| MODULE_DEVICE_TABLE(platform, lwis_driver_id); |
| |
| static struct platform_driver lwis_driver = { .probe = lwis_top_device_probe, |
| .id_table = lwis_driver_id, |
| .driver = { |
| .name = LWIS_DRIVER_NAME, |
| .owner = THIS_MODULE, |
| } }; |
| #endif /* CONFIG_OF */ |
| |
| /* |
| * lwis_top_device_init: Init function that will be called by the kernel |
| * initialization routines. |
| */ |
| int __init lwis_top_device_init(void) |
| { |
| int ret = 0; |
| |
| pr_info("Top device initialization\n"); |
| |
| ret = platform_driver_register(&lwis_driver); |
| if (ret) { |
| pr_err("platform_driver_register failed: %d\n", ret); |
| } |
| |
| return ret; |
| } |
| |
| int lwis_top_device_deinit(void) |
| { |
| platform_driver_unregister(&lwis_driver); |
| return 0; |
| } |