acpi/battery: simplify procfs code

Use remove_proc_subtree to remove the whole subtree on cleanup, and
unwind the registration loop into individual calls.  Switch to use
proc_create_seq where applicable.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 26 insertions, 95 deletions

diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index bdb24d636d9a..76550689ce10 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -81,14 +81,6 @@ MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
 #ifdef CONFIG_ACPI_PROCFS_POWER
 extern struct proc_dir_entry *acpi_lock_battery_dir(void);
 extern void *acpi_unlock_battery_dir(struct proc_dir_entry *acpi_battery_dir);
-
-enum acpi_battery_files {
-        info_tag = 0,
-        state_tag,
-        alarm_tag,
-        ACPI_BATTERY_NUMFILES,
-};
-
 #endif
 
 static const struct acpi_device_id battery_device_ids[] = {
@@ -985,9 +977,10 @@ static const char *acpi_battery_units(const struct acpi_battery *battery)
                 "mA" : "mW";
 }
 
-static int acpi_battery_print_info(struct seq_file *seq, int result)
+static int acpi_battery_info_proc_show(struct seq_file *seq, void *offset)
 {
         struct acpi_battery *battery = seq->private;
+        int result = acpi_battery_update(battery, false);
 
         if (result)
                 goto end;
@@ -1041,9 +1034,10 @@ static int acpi_battery_print_info(struct seq_file *seq, int result)
         return result;
 }
 
-static int acpi_battery_print_state(struct seq_file *seq, int result)
+static int acpi_battery_state_proc_show(struct seq_file *seq, void *offset)
 {
         struct acpi_battery *battery = seq->private;
+        int result = acpi_battery_update(battery, false);
 
         if (result)
                 goto end;
@@ -1088,9 +1082,10 @@ static int acpi_battery_print_state(struct seq_file *seq, int result)
         return result;
 }
 
-static int acpi_battery_print_alarm(struct seq_file *seq, int result)
+static int acpi_battery_alarm_proc_show(struct seq_file *seq, void *offset)
 {
         struct acpi_battery *battery = seq->private;
+        int result = acpi_battery_update(battery, false);
 
         if (result)
                 goto end;
@@ -1142,82 +1137,22 @@ static ssize_t acpi_battery_write_alarm(struct file *file,
         return result;
 }
 
-typedef int(*print_func)(struct seq_file *seq, int result);
-
-static print_func acpi_print_funcs[ACPI_BATTERY_NUMFILES] = {
-        acpi_battery_print_info,
-        acpi_battery_print_state,
-        acpi_battery_print_alarm,
-};
-
-static int acpi_battery_read(int fid, struct seq_file *seq)
+static int acpi_battery_alarm_proc_open(struct inode *inode, struct file *file)
 {
-        struct acpi_battery *battery = seq->private;
-        int result = acpi_battery_update(battery, false);
-        return acpi_print_funcs[fid](seq, result);
+        return single_open(file, acpi_battery_alarm_proc_show, PDE_DATA(inode));
 }
 
-#define DECLARE_FILE_FUNCTIONS(_name) \
-static int acpi_battery_read_##_name(struct seq_file *seq, void *offset) \
-{ \
-        return acpi_battery_read(_name##_tag, seq); \
-} \
-static int acpi_battery_##_name##_open_fs(struct inode *inode, struct file *file) \
-{ \
-        return single_open(file, acpi_battery_read_##_name, PDE_DATA(inode)); \
-}
-
-DECLARE_FILE_FUNCTIONS(info);
-DECLARE_FILE_FUNCTIONS(state);
-DECLARE_FILE_FUNCTIONS(alarm);
-
-#undef DECLARE_FILE_FUNCTIONS
-
-#define FILE_DESCRIPTION_RO(_name) \
-        { \
-        .name = __stringify(_name), \
-        .mode = S_IRUGO, \
-        .ops = { \
-                .open = acpi_battery_##_name##_open_fs, \
-                .read = seq_read, \
-                .llseek = seq_lseek, \
-                .release = single_release, \
-                .owner = THIS_MODULE, \
-                }, \
-        }
-
-#define FILE_DESCRIPTION_RW(_name) \
-        { \
-        .name = __stringify(_name), \
-        .mode = S_IFREG | S_IRUGO | S_IWUSR, \
-        .ops = { \
-                .open = acpi_battery_##_name##_open_fs, \
-                .read = seq_read, \
-                .llseek = seq_lseek, \
-                .write = acpi_battery_write_##_name, \
-                .release = single_release, \
-                .owner = THIS_MODULE, \
-                }, \
-        }
-
-static const struct battery_file {
-        struct file_operations ops;
-        umode_t mode;
-        const char *name;
-} acpi_battery_file[] = {
-        FILE_DESCRIPTION_RO(info),
-        FILE_DESCRIPTION_RO(state),
-        FILE_DESCRIPTION_RW(alarm),
+static const struct file_operations acpi_battery_alarm_fops = {
+        .owner          = THIS_MODULE,
+        .open           = acpi_battery_alarm_proc_open,
+        .read           = seq_read,
+        .write          = acpi_battery_write_alarm,
+        .llseek         = seq_lseek,
+        .release        = single_release,
 };
 
-#undef FILE_DESCRIPTION_RO
-#undef FILE_DESCRIPTION_RW
-
 static int acpi_battery_add_fs(struct acpi_device *device)
 {
-        struct proc_dir_entry *entry = NULL;
-        int i;
-
         printk(KERN_WARNING PREFIX "Deprecated procfs I/F for battery is loaded,"
                         " please retry with CONFIG_ACPI_PROCFS_POWER cleared\n");
         if (!acpi_device_dir(device)) {
@@ -1227,28 +1162,24 @@ static int acpi_battery_add_fs(struct acpi_device *device)
                         return -ENODEV;
         }
 
-        for (i = 0; i < ACPI_BATTERY_NUMFILES; ++i) {
-                entry = proc_create_data(acpi_battery_file[i].name,
-                                         acpi_battery_file[i].mode,
-                                         acpi_device_dir(device),
-                                         &acpi_battery_file[i].ops,
-                                         acpi_driver_data(device));
-                if (!entry)
-                        return -ENODEV;
-        }
+        if (!proc_create_single_data("info", S_IRUGO, acpi_device_dir(device),
+                        acpi_battery_info_proc_show, acpi_driver_data(device)))
+                return -ENODEV;
+        if (!proc_create_single_data("state", S_IRUGO, acpi_device_dir(device),
+                        acpi_battery_state_proc_show, acpi_driver_data(device)))
+                return -ENODEV;
+        if (!proc_create_data("alarm", S_IFREG | S_IRUGO | S_IWUSR,
+                        acpi_device_dir(device), &acpi_battery_alarm_fops,
+                        acpi_driver_data(device)))
+                return -ENODEV;
         return 0;
 }
 
 static void acpi_battery_remove_fs(struct acpi_device *device)
 {
-        int i;
         if (!acpi_device_dir(device))
                 return;
-        for (i = 0; i < ACPI_BATTERY_NUMFILES; ++i)
-                remove_proc_entry(acpi_battery_file[i].name,
-                                  acpi_device_dir(device));
-
-        remove_proc_entry(acpi_device_bid(device), acpi_battery_dir);
+        remove_proc_subtree(acpi_device_bid(device), acpi_battery_dir);
         acpi_device_dir(device) = NULL;
 }