ACPI: Revert "ACPI / Battery: Remove battery's proc directory"

The commit 1e2d9cd and 7d7ee95 remove ACPI Proc Battery
directory and breaks some old userspace tools. This patch
is to revert commit 1e2d9cd.

Fixes: 1e2d9cdfb449 (ACPI / Battery: Remove battery's proc directory)
Cc: 3.13+ <stable@vger.kernel.org> # 3.13+
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 328 insertions, 1 deletions

diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index 9a2c63b20050..6e7b2a12860d 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -36,6 +36,12 @@
 #include <linux/suspend.h>
 #include <asm/unaligned.h>
 
+#ifdef CONFIG_ACPI_PROCFS_POWER
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <asm/uaccess.h>
+#endif
+
 #include <linux/acpi.h>
 #include <linux/power_supply.h>
 
@@ -64,6 +70,19 @@ static unsigned int cache_time = 1000;
 module_param(cache_time, uint, 0644);
 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[] = {
         {"PNP0C0A", 0},
         {"", 0},
@@ -299,6 +318,14 @@ static enum power_supply_property energy_battery_props[] = {
         POWER_SUPPLY_PROP_SERIAL_NUMBER,
 };
 
+#ifdef CONFIG_ACPI_PROCFS_POWER
+inline char *acpi_battery_units(struct acpi_battery *battery)
+{
+        return (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA) ?
+                "mA" : "mW";
+}
+#endif
+
 /* --------------------------------------------------------------------------
                                Battery Management
    -------------------------------------------------------------------------- */
@@ -717,6 +744,279 @@ static void acpi_battery_refresh(struct acpi_battery *battery)
 }
 
 /* --------------------------------------------------------------------------
+                              FS Interface (/proc)
+   -------------------------------------------------------------------------- */
+
+#ifdef CONFIG_ACPI_PROCFS_POWER
+static struct proc_dir_entry *acpi_battery_dir;
+
+static int acpi_battery_print_info(struct seq_file *seq, int result)
+{
+        struct acpi_battery *battery = seq->private;
+
+        if (result)
+                goto end;
+
+        seq_printf(seq, "present:                 %s\n",
+                   acpi_battery_present(battery) ? "yes" : "no");
+        if (!acpi_battery_present(battery))
+                goto end;
+        if (battery->design_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
+                seq_printf(seq, "design capacity:         unknown\n");
+        else
+                seq_printf(seq, "design capacity:         %d %sh\n",
+                           battery->design_capacity,
+                           acpi_battery_units(battery));
+
+        if (battery->full_charge_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
+                seq_printf(seq, "last full capacity:      unknown\n");
+        else
+                seq_printf(seq, "last full capacity:      %d %sh\n",
+                           battery->full_charge_capacity,
+                           acpi_battery_units(battery));
+
+        seq_printf(seq, "battery technology:      %srechargeable\n",
+                   (!battery->technology)?"non-":"");
+
+        if (battery->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
+                seq_printf(seq, "design voltage:          unknown\n");
+        else
+                seq_printf(seq, "design voltage:          %d mV\n",
+                           battery->design_voltage);
+        seq_printf(seq, "design capacity warning: %d %sh\n",
+                   battery->design_capacity_warning,
+                   acpi_battery_units(battery));
+        seq_printf(seq, "design capacity low:     %d %sh\n",
+                   battery->design_capacity_low,
+                   acpi_battery_units(battery));
+        seq_printf(seq, "cycle count:             %i\n", battery->cycle_count);
+        seq_printf(seq, "capacity granularity 1:  %d %sh\n",
+                   battery->capacity_granularity_1,
+                   acpi_battery_units(battery));
+        seq_printf(seq, "capacity granularity 2:  %d %sh\n",
+                   battery->capacity_granularity_2,
+                   acpi_battery_units(battery));
+        seq_printf(seq, "model number:            %s\n", battery->model_number);
+        seq_printf(seq, "serial number:           %s\n", battery->serial_number);
+        seq_printf(seq, "battery type:            %s\n", battery->type);
+        seq_printf(seq, "OEM info:                %s\n", battery->oem_info);
+      end:
+        if (result)
+                seq_printf(seq, "ERROR: Unable to read battery info\n");
+        return result;
+}
+
+static int acpi_battery_print_state(struct seq_file *seq, int result)
+{
+        struct acpi_battery *battery = seq->private;
+
+        if (result)
+                goto end;
+
+        seq_printf(seq, "present:                 %s\n",
+                   acpi_battery_present(battery) ? "yes" : "no");
+        if (!acpi_battery_present(battery))
+                goto end;
+
+        seq_printf(seq, "capacity state:          %s\n",
+                        (battery->state & 0x04) ? "critical" : "ok");
+        if ((battery->state & 0x01) && (battery->state & 0x02))
+                seq_printf(seq,
+                           "charging state:          charging/discharging\n");
+        else if (battery->state & 0x01)
+                seq_printf(seq, "charging state:          discharging\n");
+        else if (battery->state & 0x02)
+                seq_printf(seq, "charging state:          charging\n");
+        else
+                seq_printf(seq, "charging state:          charged\n");
+
+        if (battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN)
+                seq_printf(seq, "present rate:            unknown\n");
+        else
+                seq_printf(seq, "present rate:            %d %s\n",
+                           battery->rate_now, acpi_battery_units(battery));
+
+        if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN)
+                seq_printf(seq, "remaining capacity:      unknown\n");
+        else
+                seq_printf(seq, "remaining capacity:      %d %sh\n",
+                           battery->capacity_now, acpi_battery_units(battery));
+        if (battery->voltage_now == ACPI_BATTERY_VALUE_UNKNOWN)
+                seq_printf(seq, "present voltage:         unknown\n");
+        else
+                seq_printf(seq, "present voltage:         %d mV\n",
+                           battery->voltage_now);
+      end:
+        if (result)
+                seq_printf(seq, "ERROR: Unable to read battery state\n");
+
+        return result;
+}
+
+static int acpi_battery_print_alarm(struct seq_file *seq, int result)
+{
+        struct acpi_battery *battery = seq->private;
+
+        if (result)
+                goto end;
+
+        if (!acpi_battery_present(battery)) {
+                seq_printf(seq, "present:                 no\n");
+                goto end;
+        }
+        seq_printf(seq, "alarm:                   ");
+        if (!battery->alarm)
+                seq_printf(seq, "unsupported\n");
+        else
+                seq_printf(seq, "%u %sh\n", battery->alarm,
+                                acpi_battery_units(battery));
+      end:
+        if (result)
+                seq_printf(seq, "ERROR: Unable to read battery alarm\n");
+        return result;
+}
+
+static ssize_t acpi_battery_write_alarm(struct file *file,
+                                        const char __user * buffer,
+                                        size_t count, loff_t * ppos)
+{
+        int result = 0;
+        char alarm_string[12] = { '\0' };
+        struct seq_file *m = file->private_data;
+        struct acpi_battery *battery = m->private;
+
+        if (!battery || (count > sizeof(alarm_string) - 1))
+                return -EINVAL;
+        if (!acpi_battery_present(battery)) {
+                result = -ENODEV;
+                goto end;
+        }
+        if (copy_from_user(alarm_string, buffer, count)) {
+                result = -EFAULT;
+                goto end;
+        }
+        alarm_string[count] = '\0';
+        battery->alarm = simple_strtol(alarm_string, NULL, 0);
+        result = acpi_battery_set_alarm(battery);
+      end:
+        if (!result)
+                return count;
+        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)
+{
+        struct acpi_battery *battery = seq->private;
+        int result = acpi_battery_update(battery);
+        return acpi_print_funcs[fid](seq, result);
+}
+
+#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),
+};
+
+#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)) {
+                acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
+                                                     acpi_battery_dir);
+                if (!acpi_device_dir(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;
+        }
+        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);
+        acpi_device_dir(device) = NULL;
+}
+
+#endif
+
+/* --------------------------------------------------------------------------
                                  Driver Interface
    -------------------------------------------------------------------------- */
 
@@ -790,6 +1090,15 @@ static int acpi_battery_add(struct acpi_device *device)
         result = acpi_battery_update(battery);
         if (result)
                 goto fail;
+#ifdef CONFIG_ACPI_PROCFS_POWER
+        result = acpi_battery_add_fs(device);
+#endif
+        if (result) {
+#ifdef CONFIG_ACPI_PROCFS_POWER
+                acpi_battery_remove_fs(device);
+#endif
+                goto fail;
+        }
 
         printk(KERN_INFO PREFIX "%s Slot [%s] (battery %s)\n",
                 ACPI_BATTERY_DEVICE_NAME, acpi_device_bid(device),
@@ -816,6 +1125,9 @@ static int acpi_battery_remove(struct acpi_device *device)
                 return -EINVAL;
         battery = acpi_driver_data(device);
         unregister_pm_notifier(&battery->pm_nb);
+#ifdef CONFIG_ACPI_PROCFS_POWER
+        acpi_battery_remove_fs(device);
+#endif
         sysfs_remove_battery(battery);
         mutex_destroy(&battery->lock);
         mutex_destroy(&battery->sysfs_lock);
@@ -866,7 +1178,19 @@ static void __init acpi_battery_init_async(void *unused, async_cookie_t cookie)
 
         if (dmi_check_system(bat_dmi_table))
                 battery_bix_broken_package = 1;
-        acpi_bus_register_driver(&acpi_battery_driver);
+        
+#ifdef CONFIG_ACPI_PROCFS_POWER
+        acpi_battery_dir = acpi_lock_battery_dir();
+        if (!acpi_battery_dir)
+                return;
+#endif
+        if (acpi_bus_register_driver(&acpi_battery_driver) < 0) {
+#ifdef CONFIG_ACPI_PROCFS_POWER
+                acpi_unlock_battery_dir(acpi_battery_dir);
+#endif
+                return;
+        }
+        return;
 }
 
 static int __init acpi_battery_init(void)
@@ -878,6 +1202,9 @@ static int __init acpi_battery_init(void)
 static void __exit acpi_battery_exit(void)
 {
         acpi_bus_unregister_driver(&acpi_battery_driver);
+#ifdef CONFIG_ACPI_PROCFS_POWER
+        acpi_unlock_battery_dir(acpi_battery_dir);
+#endif
 }
 
 module_init(acpi_battery_init);