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-rw-r--r--drivers/mailbox/mailbox-test.c79
1 files changed, 71 insertions, 8 deletions
diff --git a/drivers/mailbox/mailbox-test.c b/drivers/mailbox/mailbox-test.c
index deb9c61aebb4..383a8b7600ac 100644
--- a/drivers/mailbox/mailbox-test.c
+++ b/drivers/mailbox/mailbox-test.c
@@ -11,12 +11,14 @@
#include <linux/debugfs.h>
#include <linux/err.h>
+#include <linux/fs.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mailbox_client.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
+#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
@@ -39,6 +41,8 @@ struct mbox_test_device {
char *signal;
char *message;
spinlock_t lock;
+ wait_queue_head_t waitq;
+ struct fasync_struct *async_queue;
};
static ssize_t mbox_test_signal_write(struct file *filp,
@@ -81,6 +85,13 @@ static const struct file_operations mbox_test_signal_ops = {
.llseek = generic_file_llseek,
};
+static int mbox_test_message_fasync(int fd, struct file *filp, int on)
+{
+ struct mbox_test_device *tdev = filp->private_data;
+
+ return fasync_helper(fd, filp, on, &tdev->async_queue);
+}
+
static ssize_t mbox_test_message_write(struct file *filp,
const char __user *userbuf,
size_t count, loff_t *ppos)
@@ -138,6 +149,20 @@ out:
return ret < 0 ? ret : count;
}
+static bool mbox_test_message_data_ready(struct mbox_test_device *tdev)
+{
+ unsigned char data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&tdev->lock, flags);
+ data = tdev->rx_buffer[0];
+ spin_unlock_irqrestore(&tdev->lock, flags);
+
+ if (data != '\0')
+ return true;
+ return false;
+}
+
static ssize_t mbox_test_message_read(struct file *filp, char __user *userbuf,
size_t count, loff_t *ppos)
{
@@ -147,6 +172,8 @@ static ssize_t mbox_test_message_read(struct file *filp, char __user *userbuf,
int l = 0;
int ret;
+ DECLARE_WAITQUEUE(wait, current);
+
touser = kzalloc(MBOX_HEXDUMP_MAX_LEN + 1, GFP_KERNEL);
if (!touser)
return -ENOMEM;
@@ -155,15 +182,29 @@ static ssize_t mbox_test_message_read(struct file *filp, char __user *userbuf,
ret = snprintf(touser, 20, "<NO RX CAPABILITY>\n");
ret = simple_read_from_buffer(userbuf, count, ppos,
touser, ret);
- goto out;
+ goto kfree_err;
}
- if (tdev->rx_buffer[0] == '\0') {
- ret = snprintf(touser, 9, "<EMPTY>\n");
- ret = simple_read_from_buffer(userbuf, count, ppos,
- touser, ret);
- goto out;
- }
+ add_wait_queue(&tdev->waitq, &wait);
+
+ do {
+ __set_current_state(TASK_INTERRUPTIBLE);
+
+ if (mbox_test_message_data_ready(tdev))
+ break;
+
+ if (filp->f_flags & O_NONBLOCK) {
+ ret = -EAGAIN;
+ goto waitq_err;
+ }
+
+ if (signal_pending(current)) {
+ ret = -ERESTARTSYS;
+ goto waitq_err;
+ }
+ schedule();
+
+ } while (1);
spin_lock_irqsave(&tdev->lock, flags);
@@ -185,14 +226,31 @@ static ssize_t mbox_test_message_read(struct file *filp, char __user *userbuf,
spin_unlock_irqrestore(&tdev->lock, flags);
ret = simple_read_from_buffer(userbuf, count, ppos, touser, MBOX_HEXDUMP_MAX_LEN);
-out:
+waitq_err:
+ __set_current_state(TASK_RUNNING);
+ remove_wait_queue(&tdev->waitq, &wait);
+kfree_err:
kfree(touser);
return ret;
}
+static unsigned int
+mbox_test_message_poll(struct file *filp, struct poll_table_struct *wait)
+{
+ struct mbox_test_device *tdev = filp->private_data;
+
+ poll_wait(filp, &tdev->waitq, wait);
+
+ if (mbox_test_message_data_ready(tdev))
+ return POLLIN | POLLRDNORM;
+ return 0;
+}
+
static const struct file_operations mbox_test_message_ops = {
.write = mbox_test_message_write,
.read = mbox_test_message_read,
+ .fasync = mbox_test_message_fasync,
+ .poll = mbox_test_message_poll,
.open = simple_open,
.llseek = generic_file_llseek,
};
@@ -234,6 +292,10 @@ static void mbox_test_receive_message(struct mbox_client *client, void *message)
memcpy(tdev->rx_buffer, message, MBOX_MAX_MSG_LEN);
}
spin_unlock_irqrestore(&tdev->lock, flags);
+
+ wake_up_interruptible(&tdev->waitq);
+
+ kill_fasync(&tdev->async_queue, SIGIO, POLL_IN);
}
static void mbox_test_prepare_message(struct mbox_client *client, void *message)
@@ -334,6 +396,7 @@ static int mbox_test_probe(struct platform_device *pdev)
if (ret)
return ret;
+ init_waitqueue_head(&tdev->waitq);
dev_info(&pdev->dev, "Successfully registered\n");
return 0;

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