mfd: ab8500-debugfs: Keep count of IRQs in debugfs

This patch adds a counter to the sysfs file dynamically created
by debugfs. It also fixes an array index error.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Mattias Wallin <mattias.wallin@stericsson.com>
Reviewed-by: Mattias NILSSON <mattias.i.nilsson@stericsson.com>

diff --git a/drivers/mfd/ab8500-debugfs.c b/drivers/mfd/ab8500-debugfs.c
index 2e40e12..4699fff 100644 (file)
--- a/drivers/mfd/ab8500-debugfs.c
+++ b/drivers/mfd/ab8500-debugfs.c
@@ -23,6 +23,10 @@ static u32 debug_address;
 
 static int irq_first;
 static int irq_last;
+static u32 irq_count[AB8500_NR_IRQS];
+
+static struct device_attribute *dev_attr[AB8500_NR_IRQS];
+static char *event_name[AB8500_NR_IRQS];
 
 /**
  * struct ab8500_reg_range
@@ -364,12 +368,15 @@ static irqreturn_t ab8500_debug_handler(int irq, void *data)
 {
        char buf[16];
        struct kobject *kobj = (struct kobject *)data;
+       unsigned int irq_abb = irq - irq_first;
 
+       if (irq_abb < AB8500_NR_IRQS)
+               irq_count[irq_abb]++;
        /*
         * This makes it possible to use poll for events (POLLPRI | POLLERR)
-        * from userspace on sysfs file named irq-<nr>
+        * from userspace on sysfs file named <irq-nr>
         */
-       sprintf(buf, "irq-%d", irq);
+       sprintf(buf, "%d", irq);
        sysfs_notify(kobj, NULL, buf);
 
        return IRQ_HANDLED;
@@ -555,19 +562,26 @@ static int ab8500_subscribe_unsubscribe_open(struct inode *inode,
 }
 
 /*
- * This function is used for all interrupts and will always print
- * the same string. It is however this file sysfs_notify called on.
- * Userspace should read this file and then poll. When an event occur
+ * Userspace should use poll() on this file. When an event occur
  * the blocking poll will be released.
  */
 static ssize_t show_irq(struct device *dev,
                        struct device_attribute *attr, char *buf)
 {
-       return sprintf(buf, "irq\n");
-}
+       unsigned long name;
+       unsigned int irq_index;
+       int err;
 
-static struct device_attribute *dev_attr[AB8500_NR_IRQS];
-static char *event_name[AB8500_NR_IRQS];
+       err = strict_strtoul(attr->attr.name, 0, &name);
+       if (err)
+               return err;
+
+       irq_index = name - irq_first;
+       if (irq_index >= AB8500_NR_IRQS)
+               return -EINVAL;
+       else
+               return sprintf(buf, "%u\n", irq_count[irq_index]);
+}
 
 static ssize_t ab8500_subscribe_write(struct file *file,
                                      const char __user *user_buf,
@@ -578,6 +592,7 @@ static ssize_t ab8500_subscribe_write(struct file *file,
        int buf_size;
        unsigned long user_val;
        int err;
+       unsigned int irq_index;
 
        /* Get userspace string and assure termination */
        buf_size = min(count, (sizeof(buf)-1));
@@ -597,19 +612,23 @@ static ssize_t ab8500_subscribe_write(struct file *file,
                return -EINVAL;
        }
 
+       irq_index = user_val - irq_first;
+       if (irq_index >= AB8500_NR_IRQS)
+               return -EINVAL;
+
        /*
-        * This will create a sysfs file named irq-<nr> which userspace can
+        * This will create a sysfs file named <irq-nr> which userspace can
         * use to select or poll and get the AB8500 events
         */
-       dev_attr[user_val] = kmalloc(sizeof(struct device_attribute),
-                                    GFP_KERNEL);
-       event_name[user_val] = kmalloc(buf_size, GFP_KERNEL);
-       sprintf(event_name[user_val], "irq-%lu", user_val);
-       dev_attr[user_val]->show = show_irq;
-       dev_attr[user_val]->store = NULL;
-       dev_attr[user_val]->attr.name = event_name[user_val];
-       dev_attr[user_val]->attr.mode = S_IRUGO;
-       err = sysfs_create_file(&dev->kobj, &dev_attr[user_val]->attr);
+       dev_attr[irq_index] = kmalloc(sizeof(struct device_attribute),
+               GFP_KERNEL);
+       event_name[irq_index] = kmalloc(buf_size, GFP_KERNEL);
+       sprintf(event_name[irq_index], "%lu", user_val);
+       dev_attr[irq_index]->show = show_irq;
+       dev_attr[irq_index]->store = NULL;
+       dev_attr[irq_index]->attr.name = event_name[irq_index];
+       dev_attr[irq_index]->attr.mode = S_IRUGO;
+       err = sysfs_create_file(&dev->kobj, &dev_attr[irq_index]->attr);
        if (err < 0) {
                printk(KERN_ERR "sysfs_create_file failed %d\n", err);
                return err;
@@ -621,6 +640,7 @@ static ssize_t ab8500_subscribe_write(struct file *file,
        if (err < 0) {
                printk(KERN_ERR "request_threaded_irq failed %d, %lu\n",
                        err, user_val);
+               sysfs_remove_file(&dev->kobj, &dev_attr[irq_index]->attr);
                return err;
        }
 
@@ -636,6 +656,7 @@ static ssize_t ab8500_unsubscribe_write(struct file *file,
        int buf_size;
        unsigned long user_val;
        int err;
+       unsigned int irq_index;
 
        /* Get userspace string and assure termination */
        buf_size = min(count, (sizeof(buf)-1));
@@ -655,12 +676,20 @@ static ssize_t ab8500_unsubscribe_write(struct file *file,
                return -EINVAL;
        }
 
-       free_irq(user_val, &dev->kobj);
-       kfree(event_name[user_val]);
-       kfree(dev_attr[user_val]);
+       irq_index = user_val - irq_first;
+       if (irq_index >= AB8500_NR_IRQS)
+               return -EINVAL;
+
+       /* Set irq count to 0 when unsubscribe */
+       irq_count[irq_index] = 0;
+
+       if (dev_attr[irq_index])
+               sysfs_remove_file(&dev->kobj, &dev_attr[irq_index]->attr);
 
-       if (dev_attr[user_val])
-               sysfs_remove_file(&dev->kobj, &dev_attr[user_val]->attr);
+
+       free_irq(user_val, &dev->kobj);
+       kfree(event_name[irq_index]);
+       kfree(dev_attr[irq_index]);
 
        return buf_size;
 }