ACPI: Battery: simplify update scheme

Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 57 insertions, 223 deletions

diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index de506f39d3bd..faa70a50b807 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -27,6 +27,7 @@
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/types.h>
+#include <linux/jiffies.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 #include <asm/uaccess.h>
@@ -41,27 +42,18 @@
 #define ACPI_BATTERY_DEVICE_NAME        "Battery"
 #define ACPI_BATTERY_NOTIFY_STATUS      0x80
 #define ACPI_BATTERY_NOTIFY_INFO        0x81
-#define ACPI_BATTERY_UNITS_WATTS        "mW"
-#define ACPI_BATTERY_UNITS_AMPS         "mA"
 
 #define _COMPONENT              ACPI_BATTERY_COMPONENT
 
-#define ACPI_BATTERY_UPDATE_TIME        0
-
-#define ACPI_BATTERY_NONE_UPDATE        0
-#define ACPI_BATTERY_EASY_UPDATE        1
-#define ACPI_BATTERY_INIT_UPDATE        2
-
 ACPI_MODULE_NAME("battery");
 
 MODULE_AUTHOR("Paul Diefenbaugh");
 MODULE_DESCRIPTION("ACPI Battery Driver");
 MODULE_LICENSE("GPL");
 
-static unsigned int update_time = ACPI_BATTERY_UPDATE_TIME;
-
-/* 0 - every time, > 0 - by update_time */
-module_param(update_time, uint, 0644);
+static unsigned int cache_time = 1000;
+module_param(cache_time, uint, 0644);
+MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
 
 extern struct proc_dir_entry *acpi_lock_battery_dir(void);
 extern void *acpi_unlock_battery_dir(struct proc_dir_entry *acpi_battery_dir);
@@ -95,15 +87,12 @@ enum acpi_battery_files {
 };
 
 struct acpi_battery {
-        struct acpi_device *device;
         struct mutex lock;
-        unsigned long alarm;
-        unsigned long update_time[ACPI_BATTERY_NUMFILES];
-        int state;
+        struct acpi_device *device;
+        unsigned long update_time;
         int present_rate;
         int remaining_capacity;
         int present_voltage;
-        int power_unit;
         int design_capacity;
         int last_full_capacity;
         int technology;
@@ -112,14 +101,14 @@ struct acpi_battery {
         int design_capacity_low;
         int capacity_granularity_1;
         int capacity_granularity_2;
+        int alarm;
         char model_number[32];
         char serial_number[32];
         char type[32];
         char oem_info[32];
-        u8 present_prev;
+        int state;
+        int power_unit;
         u8 alarm_present;
-        u8 init_update;
-        u8 update[ACPI_BATTERY_NUMFILES];
 };
 
 inline int acpi_battery_present(struct acpi_battery *battery)
@@ -127,33 +116,15 @@ inline int acpi_battery_present(struct acpi_battery *battery)
         return battery->device->status.battery_present;
 }
 
-inline char *acpi_battery_power_units(struct acpi_battery *battery)
+inline char *acpi_battery_units(struct acpi_battery *battery)
 {
-        if (battery->power_unit)
-                return ACPI_BATTERY_UNITS_AMPS;
-        else
-                return ACPI_BATTERY_UNITS_WATTS;
-}
-
-inline acpi_handle acpi_battery_handle(struct acpi_battery *battery)
-{
-        return battery->device->handle;
+        return (battery->power_unit)?"mA":"mW";
 }
 
 /* --------------------------------------------------------------------------
                                Battery Management
    -------------------------------------------------------------------------- */
 
-static void acpi_battery_check_result(struct acpi_battery *battery, int result)
-{
-        if (!battery)
-                return;
-
-        if (result) {
-                battery->init_update = 1;
-        }
-}
-
 struct acpi_offsets {
         size_t offset;          /* offset inside struct acpi_sbs_battery */
         u8 mode;                /* int or string? */
@@ -228,11 +199,10 @@ static int acpi_battery_get_info(struct acpi_battery *battery)
         acpi_status status = 0;
         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 
-        battery->update_time[ACPI_BATTERY_INFO] = get_seconds();
         if (!acpi_battery_present(battery))
                 return 0;
         mutex_lock(&battery->lock);
-        status = acpi_evaluate_object(acpi_battery_handle(battery), "_BIF",
+        status = acpi_evaluate_object(battery->device->handle, "_BIF",
                                       NULL, &buffer);
         mutex_unlock(&battery->lock);
         if (ACPI_FAILURE(status)) {
@@ -251,13 +221,16 @@ static int acpi_battery_get_state(struct acpi_battery *battery)
         acpi_status status = 0;
         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 
-        battery->update_time[ACPI_BATTERY_STATE] = get_seconds();
-
         if (!acpi_battery_present(battery))
                 return 0;
 
+        if (battery->update_time &&
+            time_before(jiffies, battery->update_time +
+                        msecs_to_jiffies(cache_time)))
+                return 0;
+
         mutex_lock(&battery->lock);
-        status = acpi_evaluate_object(acpi_battery_handle(battery), "_BST",
+        status = acpi_evaluate_object(battery->device->handle, "_BST",
                                       NULL, &buffer);
         mutex_unlock(&battery->lock);
 
@@ -267,14 +240,13 @@ static int acpi_battery_get_state(struct acpi_battery *battery)
         }
         result = extract_package(battery, buffer.pointer,
                                  state_offsets, ARRAY_SIZE(state_offsets));
+        battery->update_time = jiffies;
         kfree(buffer.pointer);
         return result;
 }
 
 static int acpi_battery_get_alarm(struct acpi_battery *battery)
 {
-        battery->update_time[ACPI_BATTERY_ALARM] = get_seconds();
-
         return 0;
 }
 
@@ -285,8 +257,6 @@ static int acpi_battery_set_alarm(struct acpi_battery *battery,
         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
         struct acpi_object_list arg_list = { 1, &arg0 };
 
-        battery->update_time[ACPI_BATTERY_ALARM] = get_seconds();
-
         if (!acpi_battery_present(battery))
                 return -ENODEV;
 
@@ -296,8 +266,8 @@ static int acpi_battery_set_alarm(struct acpi_battery *battery,
         arg0.integer.value = alarm;
 
         mutex_lock(&battery->lock);
-        status = acpi_evaluate_object(acpi_battery_handle(battery), "_BTP",
-                                      &arg_list, NULL);
+        status = acpi_evaluate_object(battery->device->handle, "_BTP",
+                                 &arg_list, NULL);
         mutex_unlock(&battery->lock);
         if (ACPI_FAILURE(status))
                 return -ENODEV;
@@ -311,112 +281,36 @@ static int acpi_battery_set_alarm(struct acpi_battery *battery,
 
 static int acpi_battery_init_alarm(struct acpi_battery *battery)
 {
-        int result = 0;
         acpi_status status = AE_OK;
         acpi_handle handle = NULL;
-        unsigned long alarm = battery->alarm;
 
         /* See if alarms are supported, and if so, set default */
-
-        status = acpi_get_handle(acpi_battery_handle(battery), "_BTP", &handle);
-        if (ACPI_SUCCESS(status)) {
-                battery->alarm_present = 1;
-                if (!alarm) {
-                        alarm = battery->design_capacity_warning;
-                }
-                result = acpi_battery_set_alarm(battery, alarm);
-                if (result)
-                        goto end;
-        } else {
+        status = acpi_get_handle(battery->device->handle, "_BTP", &handle);
+        if (ACPI_FAILURE(status)) {
                 battery->alarm_present = 0;
+                return 0;
         }
-
-      end:
-
-        return result;
+        battery->alarm_present = 1;
+        if (!battery->alarm)
+                battery->alarm = battery->design_capacity_warning;
+        return acpi_battery_set_alarm(battery, battery->alarm);
 }
 
-static int acpi_battery_init_update(struct acpi_battery *battery)
+static int acpi_battery_update(struct acpi_battery *battery)
 {
-        int result = 0;
-
-        result = acpi_battery_get_status(battery);
-        if (result)
+        int saved_present = acpi_battery_present(battery);
+        int result = acpi_battery_get_status(battery);
+        if (result || !acpi_battery_present(battery))
                 return result;
-
-        battery->present_prev = acpi_battery_present(battery);
-
-        if (acpi_battery_present(battery)) {
+        if (saved_present != acpi_battery_present(battery) ||
+            !battery->update_time) {
+                battery->update_time = 0;
                 result = acpi_battery_get_info(battery);
                 if (result)
                         return result;
-                result = acpi_battery_get_state(battery);
-                if (result)
-                        return result;
-
                 acpi_battery_init_alarm(battery);
         }
-
-        return result;
-}
-
-static int acpi_battery_update(struct acpi_battery *battery,
-                               int update, int *update_result_ptr)
-{
-        int result = 0;
-        int update_result = ACPI_BATTERY_NONE_UPDATE;
-
-        if (!acpi_battery_present(battery)) {
-                update = 1;
-        }
-
-        if (battery->init_update) {
-                result = acpi_battery_init_update(battery);
-                if (result)
-                        goto end;
-                update_result = ACPI_BATTERY_INIT_UPDATE;
-        } else if (update) {
-                result = acpi_battery_get_status(battery);
-                if (result)
-                        goto end;
-                if ((!battery->present_prev & acpi_battery_present(battery))
-                    || (battery->present_prev & !acpi_battery_present(battery))) {
-                        result = acpi_battery_init_update(battery);
-                        if (result)
-                                goto end;
-                        update_result = ACPI_BATTERY_INIT_UPDATE;
-                } else {
-                        update_result = ACPI_BATTERY_EASY_UPDATE;
-                }
-        }
-
-      end:
-
-        battery->init_update = (result != 0);
-
-        *update_result_ptr = update_result;
-
-        return result;
-}
-
-static void acpi_battery_notify_update(struct acpi_battery *battery)
-{
-        acpi_battery_get_status(battery);
-
-        if (battery->init_update) {
-                return;
-        }
-
-        if ((!battery->present_prev &
-             acpi_battery_present(battery)) ||
-            (battery->present_prev &
-             !acpi_battery_present(battery))) {
-                battery->init_update = 1;
-        } else {
-                battery->update[ACPI_BATTERY_INFO] = 1;
-                battery->update[ACPI_BATTERY_STATE] = 1;
-                battery->update[ACPI_BATTERY_ALARM] = 1;
-        }
+        return acpi_battery_get_state(battery);
 }
 
 /* --------------------------------------------------------------------------
@@ -442,7 +336,7 @@ static int acpi_battery_print_info(struct seq_file *seq, int result)
 
         /* Battery Units */
 
-        units = acpi_battery_power_units(battery);
+        units = acpi_battery_units(battery);
 
         if (battery->design_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
                 seq_printf(seq, "design capacity:         unknown\n");
@@ -511,7 +405,7 @@ static int acpi_battery_print_state(struct seq_file *seq, int result)
 
         /* Battery Units */
 
-        units = acpi_battery_power_units(battery);
+        units = acpi_battery_units(battery);
 
         if (!(battery->state & 0x04))
                 seq_printf(seq, "capacity state:          ok\n");
@@ -571,13 +465,13 @@ static int acpi_battery_print_alarm(struct seq_file *seq, int result)
 
         /* Battery Units */
 
-        units = acpi_battery_power_units(battery);
+        units = acpi_battery_units(battery);
 
         seq_printf(seq, "alarm:                   ");
         if (!battery->alarm)
                 seq_printf(seq, "unsupported\n");
         else
-                seq_printf(seq, "%lu %sh\n", battery->alarm, units);
+                seq_printf(seq, "%u %sh\n", battery->alarm, units);
 
       end:
 
@@ -587,49 +481,35 @@ static int acpi_battery_print_alarm(struct seq_file *seq, int result)
         return result;
 }
 
-static ssize_t
-acpi_battery_write_alarm(struct file *file,
-                         const char __user * buffer,
-                         size_t count, loff_t * ppos)
+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;
-        int update_result = ACPI_BATTERY_NONE_UPDATE;
 
         if (!battery || (count > sizeof(alarm_string) - 1))
                 return -EINVAL;
-
-        result = acpi_battery_update(battery, 1, &update_result);
         if (result) {
                 result = -ENODEV;
                 goto end;
         }
-
         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';
-
-        result = acpi_battery_set_alarm(battery,
-                                        simple_strtoul(alarm_string, NULL, 0));
-        if (result)
-                goto end;
-
+        battery->alarm = simple_strtol(alarm_string, NULL, 0);
+        result = acpi_battery_set_alarm(battery, battery->alarm);
       end:
-
-        acpi_battery_check_result(battery, result);
-
         if (!result)
-                result = count;
+                return count;
         return result;
 }
 
@@ -648,28 +528,8 @@ static struct acpi_read_mux {
 static int acpi_battery_read(int fid, struct seq_file *seq)
 {
         struct acpi_battery *battery = seq->private;
-        int result = 0;
-        int update_result = ACPI_BATTERY_NONE_UPDATE;
-        int update = 0;
-
-        update = (get_seconds() - battery->update_time[fid] >= update_time);
-        update = (update | battery->update[fid]);
-
-        result = acpi_battery_update(battery, update, &update_result);
-        if (result)
-                goto end;
-
-        if (update_result == ACPI_BATTERY_EASY_UPDATE) {
-                result = acpi_read_funcs[fid].get(battery);
-                if (result)
-                        goto end;
-        }
-
-      end:
-        result = acpi_read_funcs[fid].print(seq, result);
-        acpi_battery_check_result(battery, result);
-        battery->update[fid] = result;
-        return result;
+        int result = acpi_battery_update(battery);
+        return acpi_read_funcs[fid].print(seq, result);
 }
 
 static int acpi_battery_read_info(struct seq_file *seq, void *offset)
@@ -793,33 +653,16 @@ static int acpi_battery_remove_fs(struct acpi_device *device)
 static void acpi_battery_notify(acpi_handle handle, u32 event, void *data)
 {
         struct acpi_battery *battery = data;
-        struct acpi_device *device = NULL;
-
+        struct acpi_device *device;
         if (!battery)
                 return;
-
         device = battery->device;
-
-        switch (event) {
-        case ACPI_BATTERY_NOTIFY_STATUS:
-        case ACPI_BATTERY_NOTIFY_INFO:
-        case ACPI_NOTIFY_BUS_CHECK:
-        case ACPI_NOTIFY_DEVICE_CHECK:
-                device = battery->device;
-                acpi_battery_notify_update(battery);
-                acpi_bus_generate_proc_event(device, event,
+        acpi_battery_update(battery);
+        acpi_bus_generate_proc_event(device, event,
+                                     acpi_battery_present(battery));
+        acpi_bus_generate_netlink_event(device->pnp.device_class,
+                                        device->dev.bus_id, event,
                                         acpi_battery_present(battery));
-                acpi_bus_generate_netlink_event(device->pnp.device_class,
-                                                  device->dev.bus_id, event,
-                                                  acpi_battery_present(battery));
-                break;
-        default:
-                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-                                  "Unsupported event [0x%x]\n", event));
-                break;
-        }
-
-        return;
 }
 
 static int acpi_battery_add(struct acpi_device *device)
@@ -840,12 +683,7 @@ static int acpi_battery_add(struct acpi_device *device)
         strcpy(acpi_device_class(device), ACPI_BATTERY_CLASS);
         acpi_driver_data(device) = battery;
         mutex_init(&battery->lock);
-        result = acpi_battery_get_status(battery);
-        if (result)
-                goto end;
-
-        battery->init_update = 1;
-
+        acpi_battery_update(battery);
         result = acpi_battery_add_fs(device);
         if (result)
                 goto end;
@@ -898,14 +736,10 @@ static int acpi_battery_remove(struct acpi_device *device, int type)
 static int acpi_battery_resume(struct acpi_device *device)
 {
         struct acpi_battery *battery;
-
         if (!device)
                 return -EINVAL;
-
-        battery = device->driver_data;
-
-        battery->init_update = 1;
-
+        battery = acpi_driver_data(device);
+        battery->update_time = 0;
         return 0;
 }