mirror of https://gitee.com/openkylin/linux.git
mfd: ab8500-debugfs: Provide a means for a user subscribe to IRQs
Allow users to subscribe to and view IRQ events live from debugfs. Signed-off-by: Lee Jones <lee.jones@linaro.org>
This commit is contained in:
Lee Jones
parent
e0f4fec030
commit
4b8ac08256
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@ -11,6 +11,9 @@
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#include <linux/module.h>
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#include <linux/debugfs.h>
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#include <linux/platform_device.h>
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#include <linux/interrupt.h>
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#include <linux/kobject.h>
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#include <linux/slab.h>
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#include <linux/mfd/abx500.h>
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#include <linux/mfd/abx500/ab8500.h>
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@ -18,6 +21,9 @@
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static u32 debug_bank;
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static u32 debug_address;
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static int irq_first;
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static int irq_last;
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/**
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* struct ab8500_reg_range
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* @first: the first address of the range
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@ -354,6 +360,21 @@ static struct ab8500_prcmu_ranges debug_ranges[AB8500_NUM_BANKS] = {
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},
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};
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static irqreturn_t ab8500_debug_handler(int irq, void *data)
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{
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char buf[16];
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struct kobject *kobj = (struct kobject *)data;
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/*
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* This makes it possible to use poll for events (POLLPRI | POLLERR)
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* from userspace on sysfs file named irq-<nr>
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*/
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sprintf(buf, "irq-%d", irq);
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sysfs_notify(kobj, NULL, buf);
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return IRQ_HANDLED;
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}
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static int ab8500_registers_print(struct seq_file *s, void *p)
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{
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struct device *dev = s->private;
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@ -519,6 +540,131 @@ static ssize_t ab8500_val_write(struct file *file,
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return count;
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}
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static int ab8500_subscribe_unsubscribe_print(struct seq_file *s, void *p)
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{
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seq_printf(s, "%d\n", irq_first);
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return 0;
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}
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static int ab8500_subscribe_unsubscribe_open(struct inode *inode,
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struct file *file)
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{
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return single_open(file, ab8500_subscribe_unsubscribe_print,
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inode->i_private);
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}
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/*
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* This function is used for all interrupts and will always print
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* the same string. It is however this file sysfs_notify called on.
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* Userspace should read this file and then poll. When an event occur
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* the blocking poll will be released.
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*/
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static ssize_t show_irq(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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return sprintf(buf, "irq\n");
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}
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static struct device_attribute *dev_attr[AB8500_NR_IRQS];
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static char *event_name[AB8500_NR_IRQS];
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static ssize_t ab8500_subscribe_write(struct file *file,
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const char __user *user_buf,
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size_t count, loff_t *ppos)
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{
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struct device *dev = ((struct seq_file *)(file->private_data))->private;
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char buf[32];
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int buf_size;
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unsigned long user_val;
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int err;
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/* Get userspace string and assure termination */
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buf_size = min(count, (sizeof(buf)-1));
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if (copy_from_user(buf, user_buf, buf_size))
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return -EFAULT;
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buf[buf_size] = 0;
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err = strict_strtoul(buf, 0, &user_val);
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if (err)
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return -EINVAL;
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if (user_val < irq_first) {
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dev_err(dev, "debugfs error input < %d\n", irq_first);
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return -EINVAL;
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}
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if (user_val > irq_last) {
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dev_err(dev, "debugfs error input > %d\n", irq_last);
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return -EINVAL;
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}
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/*
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* This will create a sysfs file named irq-<nr> which userspace can
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* use to select or poll and get the AB8500 events
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*/
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dev_attr[user_val] = kmalloc(sizeof(struct device_attribute),
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GFP_KERNEL);
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event_name[user_val] = kmalloc(buf_size, GFP_KERNEL);
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sprintf(event_name[user_val], "irq-%lu", user_val);
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dev_attr[user_val]->show = show_irq;
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dev_attr[user_val]->store = NULL;
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dev_attr[user_val]->attr.name = event_name[user_val];
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dev_attr[user_val]->attr.mode = S_IRUGO;
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err = sysfs_create_file(&dev->kobj, &dev_attr[user_val]->attr);
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if (err < 0) {
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printk(KERN_ERR "sysfs_create_file failed %d\n", err);
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return err;
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}
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err = request_threaded_irq(user_val, NULL, ab8500_debug_handler,
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IRQF_SHARED | IRQF_NO_SUSPEND,
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"ab8500-debug", &dev->kobj);
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if (err < 0) {
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printk(KERN_ERR "request_threaded_irq failed %d, %lu\n",
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err, user_val);
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return err;
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}
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return buf_size;
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}
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static ssize_t ab8500_unsubscribe_write(struct file *file,
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const char __user *user_buf,
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size_t count, loff_t *ppos)
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{
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struct device *dev = ((struct seq_file *)(file->private_data))->private;
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char buf[32];
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int buf_size;
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unsigned long user_val;
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int err;
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/* Get userspace string and assure termination */
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buf_size = min(count, (sizeof(buf)-1));
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if (copy_from_user(buf, user_buf, buf_size))
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return -EFAULT;
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buf[buf_size] = 0;
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err = strict_strtoul(buf, 0, &user_val);
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if (err)
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return -EINVAL;
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if (user_val < irq_first) {
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dev_err(dev, "debugfs error input < %d\n", irq_first);
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return -EINVAL;
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}
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if (user_val > irq_last) {
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dev_err(dev, "debugfs error input > %d\n", irq_last);
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return -EINVAL;
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}
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free_irq(user_val, &dev->kobj);
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kfree(event_name[user_val]);
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kfree(dev_attr[user_val]);
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if (dev_attr[user_val])
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sysfs_remove_file(&dev->kobj, &dev_attr[user_val]->attr);
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return buf_size;
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}
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static const struct file_operations ab8500_bank_fops = {
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.open = ab8500_bank_open,
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.write = ab8500_bank_write,
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@ -546,17 +692,51 @@ static const struct file_operations ab8500_val_fops = {
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.owner = THIS_MODULE,
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};
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static const struct file_operations ab8500_subscribe_fops = {
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.open = ab8500_subscribe_unsubscribe_open,
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.write = ab8500_subscribe_write,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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.owner = THIS_MODULE,
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};
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static const struct file_operations ab8500_unsubscribe_fops = {
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.open = ab8500_subscribe_unsubscribe_open,
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.write = ab8500_unsubscribe_write,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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.owner = THIS_MODULE,
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};
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static struct dentry *ab8500_dir;
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static struct dentry *ab8500_reg_file;
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static struct dentry *ab8500_bank_file;
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static struct dentry *ab8500_address_file;
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static struct dentry *ab8500_val_file;
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static struct dentry *ab8500_subscribe_file;
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static struct dentry *ab8500_unsubscribe_file;
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static int ab8500_debug_probe(struct platform_device *plf)
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{
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debug_bank = AB8500_MISC;
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debug_address = AB8500_REV_REG & 0x00FF;
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irq_first = platform_get_irq_byname(plf, "IRQ_FIRST");
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if (irq_first < 0) {
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dev_err(&plf->dev, "First irq not found, err %d\n",
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irq_first);
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return irq_first;
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}
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irq_last = platform_get_irq_byname(plf, "IRQ_LAST");
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if (irq_last < 0) {
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dev_err(&plf->dev, "Last irq not found, err %d\n",
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irq_last);
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return irq_last;
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}
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ab8500_dir = debugfs_create_dir(AB8500_NAME_STRING, NULL);
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if (!ab8500_dir)
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goto exit_no_debugfs;
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@ -582,8 +762,26 @@ static int ab8500_debug_probe(struct platform_device *plf)
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if (!ab8500_val_file)
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goto exit_destroy_address;
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ab8500_subscribe_file =
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debugfs_create_file("irq-subscribe",
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(S_IRUGO | S_IWUGO), ab8500_dir, &plf->dev,
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&ab8500_subscribe_fops);
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if (!ab8500_subscribe_file)
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goto exit_destroy_val;
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ab8500_unsubscribe_file =
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debugfs_create_file("irq-unsubscribe",
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(S_IRUGO | S_IWUGO), ab8500_dir, &plf->dev,
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&ab8500_unsubscribe_fops);
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if (!ab8500_unsubscribe_file)
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goto exit_destroy_subscribe;
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return 0;
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exit_destroy_subscribe:
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debugfs_remove(ab8500_subscribe_file);
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exit_destroy_val:
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debugfs_remove(ab8500_val_file);
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exit_destroy_address:
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debugfs_remove(ab8500_address_file);
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exit_destroy_bank:
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