ACPI: Battery: simplify update scheme

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

diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index de506f3..faa70a5 100644 (file)
--- 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;
 }