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path: root/drivers/net/irda/sir_kthread.c
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Diffstat (limited to 'drivers/net/irda/sir_kthread.c')
-rw-r--r--drivers/net/irda/sir_kthread.c502
1 files changed, 502 insertions, 0 deletions
diff --git a/drivers/net/irda/sir_kthread.c b/drivers/net/irda/sir_kthread.c
new file mode 100644
index 000000000000..18cea1099530
--- /dev/null
+++ b/drivers/net/irda/sir_kthread.c
@@ -0,0 +1,502 @@
+/*********************************************************************
+ *
+ * sir_kthread.c: dedicated thread to process scheduled
+ * sir device setup requests
+ *
+ * Copyright (c) 2002 Martin Diehl
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ ********************************************************************/
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/version.h>
+#include <linux/init.h>
+#include <linux/smp_lock.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+
+#include <net/irda/irda.h>
+
+#include "sir-dev.h"
+
+/**************************************************************************
+ *
+ * kIrDAd kernel thread and config state machine
+ *
+ */
+
+struct irda_request_queue {
+ struct list_head request_list;
+ spinlock_t lock;
+ task_t *thread;
+ struct completion exit;
+ wait_queue_head_t kick, done;
+ atomic_t num_pending;
+};
+
+static struct irda_request_queue irda_rq_queue;
+
+static int irda_queue_request(struct irda_request *rq)
+{
+ int ret = 0;
+ unsigned long flags;
+
+ if (!test_and_set_bit(0, &rq->pending)) {
+ spin_lock_irqsave(&irda_rq_queue.lock, flags);
+ list_add_tail(&rq->lh_request, &irda_rq_queue.request_list);
+ wake_up(&irda_rq_queue.kick);
+ atomic_inc(&irda_rq_queue.num_pending);
+ spin_unlock_irqrestore(&irda_rq_queue.lock, flags);
+ ret = 1;
+ }
+ return ret;
+}
+
+static void irda_request_timer(unsigned long data)
+{
+ struct irda_request *rq = (struct irda_request *)data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&irda_rq_queue.lock, flags);
+ list_add_tail(&rq->lh_request, &irda_rq_queue.request_list);
+ wake_up(&irda_rq_queue.kick);
+ spin_unlock_irqrestore(&irda_rq_queue.lock, flags);
+}
+
+static int irda_queue_delayed_request(struct irda_request *rq, unsigned long delay)
+{
+ int ret = 0;
+ struct timer_list *timer = &rq->timer;
+
+ if (!test_and_set_bit(0, &rq->pending)) {
+ timer->expires = jiffies + delay;
+ timer->function = irda_request_timer;
+ timer->data = (unsigned long)rq;
+ atomic_inc(&irda_rq_queue.num_pending);
+ add_timer(timer);
+ ret = 1;
+ }
+ return ret;
+}
+
+static void run_irda_queue(void)
+{
+ unsigned long flags;
+ struct list_head *entry, *tmp;
+ struct irda_request *rq;
+
+ spin_lock_irqsave(&irda_rq_queue.lock, flags);
+ list_for_each_safe(entry, tmp, &irda_rq_queue.request_list) {
+ rq = list_entry(entry, struct irda_request, lh_request);
+ list_del_init(entry);
+ spin_unlock_irqrestore(&irda_rq_queue.lock, flags);
+
+ clear_bit(0, &rq->pending);
+ rq->func(rq->data);
+
+ if (atomic_dec_and_test(&irda_rq_queue.num_pending))
+ wake_up(&irda_rq_queue.done);
+
+ spin_lock_irqsave(&irda_rq_queue.lock, flags);
+ }
+ spin_unlock_irqrestore(&irda_rq_queue.lock, flags);
+}
+
+static int irda_thread(void *startup)
+{
+ DECLARE_WAITQUEUE(wait, current);
+
+ daemonize("kIrDAd");
+
+ irda_rq_queue.thread = current;
+
+ complete((struct completion *)startup);
+
+ while (irda_rq_queue.thread != NULL) {
+
+ /* We use TASK_INTERRUPTIBLE, rather than
+ * TASK_UNINTERRUPTIBLE. Andrew Morton made this
+ * change ; he told me that it is safe, because "signal
+ * blocking is now handled in daemonize()", he added
+ * that the problem is that "uninterruptible sleep
+ * contributes to load average", making user worry.
+ * Jean II */
+ set_task_state(current, TASK_INTERRUPTIBLE);
+ add_wait_queue(&irda_rq_queue.kick, &wait);
+ if (list_empty(&irda_rq_queue.request_list))
+ schedule();
+ else
+ __set_task_state(current, TASK_RUNNING);
+ remove_wait_queue(&irda_rq_queue.kick, &wait);
+
+ /* make swsusp happy with our thread */
+ if (current->flags & PF_FREEZE)
+ refrigerator(PF_FREEZE);
+
+ run_irda_queue();
+ }
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,5,35)
+ reparent_to_init();
+#endif
+ complete_and_exit(&irda_rq_queue.exit, 0);
+ /* never reached */
+ return 0;
+}
+
+
+static void flush_irda_queue(void)
+{
+ if (atomic_read(&irda_rq_queue.num_pending)) {
+
+ DECLARE_WAITQUEUE(wait, current);
+
+ if (!list_empty(&irda_rq_queue.request_list))
+ run_irda_queue();
+
+ set_task_state(current, TASK_UNINTERRUPTIBLE);
+ add_wait_queue(&irda_rq_queue.done, &wait);
+ if (atomic_read(&irda_rq_queue.num_pending))
+ schedule();
+ else
+ __set_task_state(current, TASK_RUNNING);
+ remove_wait_queue(&irda_rq_queue.done, &wait);
+ }
+}
+
+/* substate handler of the config-fsm to handle the cases where we want
+ * to wait for transmit completion before changing the port configuration
+ */
+
+static int irda_tx_complete_fsm(struct sir_dev *dev)
+{
+ struct sir_fsm *fsm = &dev->fsm;
+ unsigned next_state, delay;
+ unsigned bytes_left;
+
+ do {
+ next_state = fsm->substate; /* default: stay in current substate */
+ delay = 0;
+
+ switch(fsm->substate) {
+
+ case SIRDEV_STATE_WAIT_XMIT:
+ if (dev->drv->chars_in_buffer)
+ bytes_left = dev->drv->chars_in_buffer(dev);
+ else
+ bytes_left = 0;
+ if (!bytes_left) {
+ next_state = SIRDEV_STATE_WAIT_UNTIL_SENT;
+ break;
+ }
+
+ if (dev->speed > 115200)
+ delay = (bytes_left*8*10000) / (dev->speed/100);
+ else if (dev->speed > 0)
+ delay = (bytes_left*10*10000) / (dev->speed/100);
+ else
+ delay = 0;
+ /* expected delay (usec) until remaining bytes are sent */
+ if (delay < 100) {
+ udelay(delay);
+ delay = 0;
+ break;
+ }
+ /* sleep some longer delay (msec) */
+ delay = (delay+999) / 1000;
+ break;
+
+ case SIRDEV_STATE_WAIT_UNTIL_SENT:
+ /* block until underlaying hardware buffer are empty */
+ if (dev->drv->wait_until_sent)
+ dev->drv->wait_until_sent(dev);
+ next_state = SIRDEV_STATE_TX_DONE;
+ break;
+
+ case SIRDEV_STATE_TX_DONE:
+ return 0;
+
+ default:
+ IRDA_ERROR("%s - undefined state\n", __FUNCTION__);
+ return -EINVAL;
+ }
+ fsm->substate = next_state;
+ } while (delay == 0);
+ return delay;
+}
+
+/*
+ * Function irda_config_fsm
+ *
+ * State machine to handle the configuration of the device (and attached dongle, if any).
+ * This handler is scheduled for execution in kIrDAd context, so we can sleep.
+ * however, kIrDAd is shared by all sir_dev devices so we better don't sleep there too
+ * long. Instead, for longer delays we start a timer to reschedule us later.
+ * On entry, fsm->sem is always locked and the netdev xmit queue stopped.
+ * Both must be unlocked/restarted on completion - but only on final exit.
+ */
+
+static void irda_config_fsm(void *data)
+{
+ struct sir_dev *dev = data;
+ struct sir_fsm *fsm = &dev->fsm;
+ int next_state;
+ int ret = -1;
+ unsigned delay;
+
+ IRDA_DEBUG(2, "%s(), <%ld>\n", __FUNCTION__, jiffies);
+
+ do {
+ IRDA_DEBUG(3, "%s - state=0x%04x / substate=0x%04x\n",
+ __FUNCTION__, fsm->state, fsm->substate);
+
+ next_state = fsm->state;
+ delay = 0;
+
+ switch(fsm->state) {
+
+ case SIRDEV_STATE_DONGLE_OPEN:
+ if (dev->dongle_drv != NULL) {
+ ret = sirdev_put_dongle(dev);
+ if (ret) {
+ fsm->result = -EINVAL;
+ next_state = SIRDEV_STATE_ERROR;
+ break;
+ }
+ }
+
+ /* Initialize dongle */
+ ret = sirdev_get_dongle(dev, fsm->param);
+ if (ret) {
+ fsm->result = ret;
+ next_state = SIRDEV_STATE_ERROR;
+ break;
+ }
+
+ /* Dongles are powered through the modem control lines which
+ * were just set during open. Before resetting, let's wait for
+ * the power to stabilize. This is what some dongle drivers did
+ * in open before, while others didn't - should be safe anyway.
+ */
+
+ delay = 50;
+ fsm->substate = SIRDEV_STATE_DONGLE_RESET;
+ next_state = SIRDEV_STATE_DONGLE_RESET;
+
+ fsm->param = 9600;
+
+ break;
+
+ case SIRDEV_STATE_DONGLE_CLOSE:
+ /* shouldn't we just treat this as success=? */
+ if (dev->dongle_drv == NULL) {
+ fsm->result = -EINVAL;
+ next_state = SIRDEV_STATE_ERROR;
+ break;
+ }
+
+ ret = sirdev_put_dongle(dev);
+ if (ret) {
+ fsm->result = ret;
+ next_state = SIRDEV_STATE_ERROR;
+ break;
+ }
+ next_state = SIRDEV_STATE_DONE;
+ break;
+
+ case SIRDEV_STATE_SET_DTR_RTS:
+ ret = sirdev_set_dtr_rts(dev,
+ (fsm->param&0x02) ? TRUE : FALSE,
+ (fsm->param&0x01) ? TRUE : FALSE);
+ next_state = SIRDEV_STATE_DONE;
+ break;
+
+ case SIRDEV_STATE_SET_SPEED:
+ fsm->substate = SIRDEV_STATE_WAIT_XMIT;
+ next_state = SIRDEV_STATE_DONGLE_CHECK;
+ break;
+
+ case SIRDEV_STATE_DONGLE_CHECK:
+ ret = irda_tx_complete_fsm(dev);
+ if (ret < 0) {
+ fsm->result = ret;
+ next_state = SIRDEV_STATE_ERROR;
+ break;
+ }
+ if ((delay=ret) != 0)
+ break;
+
+ if (dev->dongle_drv) {
+ fsm->substate = SIRDEV_STATE_DONGLE_RESET;
+ next_state = SIRDEV_STATE_DONGLE_RESET;
+ }
+ else {
+ dev->speed = fsm->param;
+ next_state = SIRDEV_STATE_PORT_SPEED;
+ }
+ break;
+
+ case SIRDEV_STATE_DONGLE_RESET:
+ if (dev->dongle_drv->reset) {
+ ret = dev->dongle_drv->reset(dev);
+ if (ret < 0) {
+ fsm->result = ret;
+ next_state = SIRDEV_STATE_ERROR;
+ break;
+ }
+ }
+ else
+ ret = 0;
+ if ((delay=ret) == 0) {
+ /* set serial port according to dongle default speed */
+ if (dev->drv->set_speed)
+ dev->drv->set_speed(dev, dev->speed);
+ fsm->substate = SIRDEV_STATE_DONGLE_SPEED;
+ next_state = SIRDEV_STATE_DONGLE_SPEED;
+ }
+ break;
+
+ case SIRDEV_STATE_DONGLE_SPEED:
+ if (dev->dongle_drv->reset) {
+ ret = dev->dongle_drv->set_speed(dev, fsm->param);
+ if (ret < 0) {
+ fsm->result = ret;
+ next_state = SIRDEV_STATE_ERROR;
+ break;
+ }
+ }
+ else
+ ret = 0;
+ if ((delay=ret) == 0)
+ next_state = SIRDEV_STATE_PORT_SPEED;
+ break;
+
+ case SIRDEV_STATE_PORT_SPEED:
+ /* Finally we are ready to change the serial port speed */
+ if (dev->drv->set_speed)
+ dev->drv->set_speed(dev, dev->speed);
+ dev->new_speed = 0;
+ next_state = SIRDEV_STATE_DONE;
+ break;
+
+ case SIRDEV_STATE_DONE:
+ /* Signal network layer so it can send more frames */
+ netif_wake_queue(dev->netdev);
+ next_state = SIRDEV_STATE_COMPLETE;
+ break;
+
+ default:
+ IRDA_ERROR("%s - undefined state\n", __FUNCTION__);
+ fsm->result = -EINVAL;
+ /* fall thru */
+
+ case SIRDEV_STATE_ERROR:
+ IRDA_ERROR("%s - error: %d\n", __FUNCTION__, fsm->result);
+
+#if 0 /* don't enable this before we have netdev->tx_timeout to recover */
+ netif_stop_queue(dev->netdev);
+#else
+ netif_wake_queue(dev->netdev);
+#endif
+ /* fall thru */
+
+ case SIRDEV_STATE_COMPLETE:
+ /* config change finished, so we are not busy any longer */
+ sirdev_enable_rx(dev);
+ up(&fsm->sem);
+ return;
+ }
+ fsm->state = next_state;
+ } while(!delay);
+
+ irda_queue_delayed_request(&fsm->rq, msecs_to_jiffies(delay));
+}
+
+/* schedule some device configuration task for execution by kIrDAd
+ * on behalf of the above state machine.
+ * can be called from process or interrupt/tasklet context.
+ */
+
+int sirdev_schedule_request(struct sir_dev *dev, int initial_state, unsigned param)
+{
+ struct sir_fsm *fsm = &dev->fsm;
+ int xmit_was_down;
+
+ IRDA_DEBUG(2, "%s - state=0x%04x / param=%u\n", __FUNCTION__, initial_state, param);
+
+ if (down_trylock(&fsm->sem)) {
+ if (in_interrupt() || in_atomic() || irqs_disabled()) {
+ IRDA_DEBUG(1, "%s(), state machine busy!\n", __FUNCTION__);
+ return -EWOULDBLOCK;
+ } else
+ down(&fsm->sem);
+ }
+
+ if (fsm->state == SIRDEV_STATE_DEAD) {
+ /* race with sirdev_close should never happen */
+ IRDA_ERROR("%s(), instance staled!\n", __FUNCTION__);
+ up(&fsm->sem);
+ return -ESTALE; /* or better EPIPE? */
+ }
+
+ xmit_was_down = netif_queue_stopped(dev->netdev);
+ netif_stop_queue(dev->netdev);
+ atomic_set(&dev->enable_rx, 0);
+
+ fsm->state = initial_state;
+ fsm->param = param;
+ fsm->result = 0;
+
+ INIT_LIST_HEAD(&fsm->rq.lh_request);
+ fsm->rq.pending = 0;
+ fsm->rq.func = irda_config_fsm;
+ fsm->rq.data = dev;
+
+ if (!irda_queue_request(&fsm->rq)) { /* returns 0 on error! */
+ atomic_set(&dev->enable_rx, 1);
+ if (!xmit_was_down)
+ netif_wake_queue(dev->netdev);
+ up(&fsm->sem);
+ return -EAGAIN;
+ }
+ return 0;
+}
+
+int __init irda_thread_create(void)
+{
+ struct completion startup;
+ int pid;
+
+ spin_lock_init(&irda_rq_queue.lock);
+ irda_rq_queue.thread = NULL;
+ INIT_LIST_HEAD(&irda_rq_queue.request_list);
+ init_waitqueue_head(&irda_rq_queue.kick);
+ init_waitqueue_head(&irda_rq_queue.done);
+ atomic_set(&irda_rq_queue.num_pending, 0);
+
+ init_completion(&startup);
+ pid = kernel_thread(irda_thread, &startup, CLONE_FS|CLONE_FILES);
+ if (pid <= 0)
+ return -EAGAIN;
+ else
+ wait_for_completion(&startup);
+
+ return 0;
+}
+
+void __exit irda_thread_join(void)
+{
+ if (irda_rq_queue.thread) {
+ flush_irda_queue();
+ init_completion(&irda_rq_queue.exit);
+ irda_rq_queue.thread = NULL;
+ wake_up(&irda_rq_queue.kick);
+ wait_for_completion(&irda_rq_queue.exit);
+ }
+}
+
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.