1 files changed, 266 insertions, 0 deletions
diff --git a/drivers/mxc/hw_event/mxc_hw_event.c b/drivers/mxc/hw_event/mxc_hw_event.c
new file mode 100644
index 000000000000..655e4c821986
--- /dev/null
+++ b/drivers/mxc/hw_event/mxc_hw_event.c
@@ -0,0 +1,266 @@
+/*
+ * Copyright 2007-2010 Freescale Semiconductor, Inc. All Rights Reserved.
+ */
+
+/*
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+/*!
+ * mxc_hw_event.c
+ * Collect the hardware events, send to user by netlink
+ */
+
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/netlink.h>
+#include <linux/sched.h>
+#include <linux/list.h>
+#include <linux/signal.h>
+#include <linux/freezer.h>
+#include <linux/kthread.h>
+#include <net/sock.h>
+
+#include <mach/hw_events.h>
+
+#define EVENT_POOL_SIZE	10
+
+struct hw_event_elem {
+	struct mxc_hw_event event;
+	struct list_head list;
+};
+
+static struct sock *nl_event_sock;	/* netlink socket */
+static struct list_head event_head;
+static struct list_head free_head;
+static struct hw_event_elem events_pool[EVENT_POOL_SIZE];	/* event pool */
+static DEFINE_SPINLOCK(list_lock);
+static DECLARE_WAIT_QUEUE_HEAD(event_wq);
+static unsigned int seq;	/* send seq */
+static int initialized;
+static struct task_struct *hwevent_kthread;
+
+/*!
+ * main HW event handler thread
+ */
+static int hw_event_thread(void *data)
+{
+	struct sk_buff *skb = NULL;
+	struct nlmsghdr *nlh = NULL;
+	unsigned int size;
+	struct hw_event_elem *event, *n;
+	LIST_HEAD(tmp_head);
+	DEFINE_WAIT(wait);
+
+	while (1) {
+
+		prepare_to_wait(&event_wq, &wait, TASK_INTERRUPTIBLE);
+		/* wait for event coming */
+		if (!freezing(current) && !kthread_should_stop() &&
+		    list_empty(&event_head))
+			schedule();
+		finish_wait(&event_wq, &wait);
+
+		try_to_freeze();
+
+		if (kthread_should_stop())
+			break;
+
+		/* fetch event from list */
+		spin_lock_irq(&list_lock);
+		tmp_head = event_head;
+		tmp_head.prev->next = &tmp_head;
+		tmp_head.next->prev = &tmp_head;
+		/* clear the event list head */
+		INIT_LIST_HEAD(&event_head);
+		spin_unlock_irq(&list_lock);
+
+		list_for_each_entry_safe(event, n, &tmp_head, list) {
+
+			size = NLMSG_SPACE(sizeof(struct mxc_hw_event));
+			skb = alloc_skb(size, GFP_KERNEL);
+			if (!skb) {
+				/* if failed alloc skb, we drop this event */
+				printk(KERN_WARNING
+				       "mxc_hw_event: skb_alloc() failed\n");
+				goto alloc_failure;
+			}
+
+			/* put the netlink header struct to skb */
+			nlh =
+			    NLMSG_PUT(skb, 0, seq++, NLMSG_DONE,
+				      size - sizeof(*nlh));
+
+			/* fill the netlink data */
+			memcpy((struct mxc_hw_event *)NLMSG_DATA(nlh),
+			       &event->event, sizeof(struct mxc_hw_event));
+
+			/* free the event node, set to unused */
+			spin_lock_irq(&list_lock);
+			list_move(&event->list, &free_head);
+			spin_unlock_irq(&list_lock);
+
+			/* send to all process that create this socket */
+			NETLINK_CB(skb).pid = 0;	/* sender pid */
+			NETLINK_CB(skb).dst_group = HW_EVENT_GROUP;
+			/* broadcast the event */
+			netlink_broadcast(nl_event_sock, skb, 0, HW_EVENT_GROUP,
+					  GFP_KERNEL);
+
+			continue;
+		      nlmsg_failure:
+			printk(KERN_WARNING
+			       "mxc_hw_event: No tailroom for NLMSG in skb\n");
+		      alloc_failure:
+			/* free the event node, set to unused */
+			spin_lock_irq(&list_lock);
+			list_del(&event->list);
+			list_add_tail(&event->list, &free_head);
+			spin_unlock_irq(&list_lock);
+		}
+	}
+
+	return 0;
+}
+
+/*!
+ *
+ * @priority the event priority, REALTIME, EMERENCY, NORMAL
+ * @new_event event id to be send
+ */
+int hw_event_send(int priority, struct mxc_hw_event *new_event)
+{
+	unsigned int size;
+	struct sk_buff *skb = NULL;
+	struct nlmsghdr *nlh = NULL;
+	struct mxc_hw_event *event;
+	struct hw_event_elem *event_elem;
+	int ret;
+	unsigned long flag;
+	struct list_head *list_node;
+
+	if (!initialized) {
+		pr_info("HW Event module has not been initialized\n");
+		return -1;
+	}
+
+	if (priority == HWE_HIGH_PRIORITY) {
+		/**
+		 * the most high priority event,
+		 * we send it immediatly.
+		 */
+
+		size = NLMSG_SPACE(sizeof(struct mxc_hw_event));
+
+		/* alloc skb */
+		if (in_interrupt()) {
+			skb = alloc_skb(size, GFP_ATOMIC);
+		} else {
+			skb = alloc_skb(size, GFP_KERNEL);
+		}
+		if (!skb) {
+			/* if failed alloc skb, we drop this event */
+			printk(KERN_WARNING
+			       "hw_event send: skb_alloc() failed\n");
+			goto send_later;
+		}
+
+		/* put the netlink header struct to skb */
+		nlh = NLMSG_PUT(skb, 0, seq++, NLMSG_DONE, size - sizeof(*nlh));
+
+		/* fill the netlink data */
+		event = (struct mxc_hw_event *)NLMSG_DATA(nlh);
+		memcpy(event, new_event, sizeof(struct mxc_hw_event));
+
+		/* send to all process that create this socket */
+		NETLINK_CB(skb).pid = 0;	/* sender pid */
+		NETLINK_CB(skb).dst_group = HW_EVENT_GROUP;
+		/* broadcast the event */
+		ret = netlink_broadcast(nl_event_sock, skb, 0, HW_EVENT_GROUP,
+					in_interrupt() ? GFP_ATOMIC :
+					GFP_KERNEL);
+		if (ret) {
+
+		      nlmsg_failure:
+			/* send failed */
+			kfree_skb(skb);
+			goto send_later;
+		}
+
+		return 0;
+	}
+
+      send_later:
+	spin_lock_irqsave(&list_lock, flag);
+	if (list_empty(&free_head)) {
+		spin_unlock_irqrestore(&list_lock, flag);
+		/* no more free event node */
+		printk(KERN_WARNING "mxc_event send: no more free node\n");
+		return -1;
+	}
+
+	/* get a free node from free list, and added to event list */
+	list_node = free_head.next;
+	/* fill event */
+	event_elem = list_entry(list_node, struct hw_event_elem, list);
+	event_elem->event = *new_event;
+	list_move(list_node, &event_head);
+	spin_unlock_irqrestore(&list_lock, flag);
+
+	wake_up(&event_wq);
+
+	return 0;
+}
+
+static int __init mxc_hw_event_init(void)
+{
+	int i;
+
+	/* initial the list head for event and free */
+	INIT_LIST_HEAD(&free_head);
+	INIT_LIST_HEAD(&event_head);
+
+	/* initial the free list */
+	for (i = 0; i < EVENT_POOL_SIZE; i++)
+		list_add_tail(&events_pool[i].list, &free_head);
+
+	/* create netlink kernel sock */
+	nl_event_sock =
+	    netlink_kernel_create(&init_net, NETLINK_USERSOCK, 0, NULL, NULL,
+				  THIS_MODULE);
+	if (!nl_event_sock) {
+		printk(KERN_WARNING
+		       "mxc_hw_event: Fail to create netlink socket.\n");
+		return 1;
+	}
+
+	hwevent_kthread = kthread_run(hw_event_thread, NULL, "hwevent");
+	if (IS_ERR(hwevent_kthread)) {
+		printk(KERN_WARNING
+		       "mxc_hw_event: Fail to create hwevent thread.\n");
+		return 1;
+	}
+
+	initialized = 1;
+
+	return 0;
+}
+
+static void __exit mxc_hw_event_exit(void)
+{
+	kthread_stop(hwevent_kthread);
+	/* wait for thread completion */
+	sock_release(nl_event_sock->sk_socket);
+}
+
+module_init(mxc_hw_event_init);
+module_exit(mxc_hw_event_exit);
+
+EXPORT_SYMBOL(hw_event_send);
+MODULE_LICENSE("GPL");