[PATCH] NFC: added the sysfs entry for nfcsim workqueue delay

[Saurabh Sengar]

added the sysfs entry for nfcsim workqueue delay, as tx_delay

Signed-off-by: Saurabh Sengar <saurabh.tr...@gmail.com>
---
implementing the TODO task

 drivers/nfc/nfcsim.c | 38 +++++++++++++++++++++++++++++++++++---
 1 file changed, 35 insertions(+), 3 deletions(-)

diff --git a/drivers/nfc/nfcsim.c b/drivers/nfc/nfcsim.c
index 26ac9e5..e77be35 100644
--- a/drivers/nfc/nfcsim.c
+++ b/drivers/nfc/nfcsim.c
@@ -32,6 +32,8 @@
 #define NFCSIM_POLL_TARGET     2
 #define NFCSIM_POLL_DUAL       (NFCSIM_POLL_INITIATOR | NFCSIM_POLL_TARGET)
 
+#define TX_DEFAULT_DELAY       5
+
 struct nfcsim {
        struct nfc_dev *nfc_dev;
 
@@ -62,12 +64,41 @@ static struct nfcsim *dev1;
 
 static struct workqueue_struct *wq;
 
+
+static int tx_delay = TX_DEFAULT_DELAY;
+
+static ssize_t show_tx_delay(struct device *dev,
+                                       struct device_attribute *attr,
+                                       char *buf)
+{
+       int n;
+
+       n = scnprintf(buf, PAGE_SIZE, "%d\n", tx_delay);
+       return n;
+}
+
+static ssize_t store_tx_delay(struct device *dev,
+                                       struct device_attribute *attr,
+                                       const char *buf, size_t count)
+{
+       if (kstrtouint(buf, 0, &tx_delay) < 0)
+               return -EINVAL;
+
+       if (tx_delay < 0)
+               return -EINVAL;
+
+       return count;
+}
+
+static DEVICE_ATTR(tx_delay, 0644, show_tx_delay, store_tx_delay);
+
 static void nfcsim_cleanup_dev(struct nfcsim *dev, u8 shutdown)
 {
        DEV_DBG(dev, "shutdown=%d\n", shutdown);
 
        mutex_lock(&dev->lock);
 
+       device_remove_file(&dev->nfc_dev->dev, &dev_attr_tx_delay);
        dev->polling_mode = NFCSIM_POLL_NONE;
        dev->shutting_down = shutdown;
        dev->cb = NULL;
@@ -320,10 +351,8 @@ static int nfcsim_tx(struct nfc_dev *nfc_dev, struct 
nfc_target *target,
         * If packet transmission occurs immediately between them, we have a
         * non-stop flow of several tens of thousands SYMM packets per second
         * and a burning cpu.
-        *
-        * TODO: Add support for a sysfs entry to control this delay.
         */
-       queue_delayed_work(wq, &peer->recv_work, msecs_to_jiffies(5));
+       queue_delayed_work(wq, &peer->recv_work, msecs_to_jiffies(tx_delay));
 
        mutex_unlock(&peer->lock);
 
@@ -461,6 +490,9 @@ static struct nfcsim *nfcsim_init_dev(void)
        if (rc)
                goto free_nfc_dev;
 
+       rc = device_create_file(&dev->nfc_dev->dev, &dev_attr_tx_delay);
+       if (rc)
+               pr_err("error creating sysfs entry\n");
        return dev;
 
 free_nfc_dev:
-- 
1.9.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/