max170xx_battery: disable shutdown methods from user space

BZ: 19950

This patch enables the user space to disable default shutdown
methods set by platform. By adding the disable_shutdown_methods
sysfs interface under its device directory so the user space write
into this file to disable the shutdown methods.

Usage:
To disable default fuel gauge based shutdown:
echo 1 > disable_shutdown_methods

To disable OCV based shutdown:
echo 2 > disable_shutdown_methods

To disable LOWBATT based shutdown:
echo 4 > disable_shutdown_methods

To disable all types of shutdown:
echo 7 > disable_shutdown_methods

Change-Id: Ic10034d3cf2a59fb05fa09f518d96cc843c3ea4b
Signed-off-by: Ramakrishna Pallala <ramakrishna.pallala@intel.com>
Reviewed-on: http://android.intel.com:8080/49426
Reviewed-by: Tc, Jenny <jenny.tc@intel.com>
Reviewed-by: Koskinen, Ilkka <ilkka.koskinen@intel.com>
Reviewed-by: Jena, TapanX <tapanx.jena@intel.com>
Tested-by: Kallappa Manjanna, MadhukumarX <madhukumarx.kallappa.manjanna@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>

diff --git a/drivers/power/max17042_battery.c b/drivers/power/max17042_battery.c
index 8a55de2..9aeaedf 100644 (file)
--- a/drivers/power/max17042_battery.c
+++ b/drivers/power/max17042_battery.c
@@ -113,7 +113,7 @@
 
 #define CONSTANT_TEMP_IN_POWER_SUPPLY  350
 #define POWER_SUPPLY_VOLT_MIN_THRESHOLD        3500000
-#define BATTERY_VOLT_MIN_THRESHOLD     3600000
+#define BATTERY_VOLT_MIN_THRESHOLD     3400000
 
 #define CYCLES_ROLLOVER_CUTOFF         0x00FF
 #define MAX17042_DEF_RO_LRNCFG         0x0076
@@ -127,6 +127,10 @@
 
 #define MAX17042_SIGN_INDICATOR                0x8000
 
+#define SHUTDOWN_DEF_FG_MASK_BIT       (1 << 0)
+#define SHUTDOWN_OCV_MASK_BIT          (1 << 1)
+#define SHUTDOWN_LOWBATT_MASK_BIT      (1 << 2)
+
 #define BYTE_VALUE                     1
 #define WORD_VALUE                     0
 
@@ -265,8 +269,22 @@ struct max17042_chip {
        struct work_struct      evt_worker;
 
        bool plat_rebooting;
+       /*
+        * user space can disable default shutdown
+        * methods set by platform.
+        */
+       int     disable_shdwn_methods;
 };
 
+/* Sysfs entry for disable shutdown methods from user space */
+static ssize_t override_shutdown_methods(struct device *device,
+                              struct device_attribute *attr, const char *buf,
+                              size_t count);
+static ssize_t get_shutdown_methods(struct device *device,
+                              struct device_attribute *attr, char *buf);
+static DEVICE_ATTR(disable_shutdown_methods, S_IRUGO | S_IWUSR,
+       get_shutdown_methods, override_shutdown_methods);
+
 #ifdef CONFIG_DEBUG_FS
 static struct dentry *max17042_dbgfs_root;
 static char max17042_dbg_regs[MAX17042_MAX_MEM][4];
@@ -618,23 +636,33 @@ static int max17042_get_property(struct power_supply *psy,
                        else
                                batt_vmin = BATTERY_VOLT_MIN_THRESHOLD;
 
-                       if (chip->pdata->enable_current_sense &&
-                                       (volt_ocv <= batt_vmin)) {
-                               val->intval = 0;
+                       if (volt_ocv <= batt_vmin) {
+                               /* if user disables OCV shutdown method
+                                * report 1% capcity so that platform
+                                * will not get shutdown.
+                                */
+                               if (chip->disable_shdwn_methods &
+                                               SHUTDOWN_OCV_MASK_BIT)
+                                       val->intval = 1;
+                               else
+                                       val->intval = 0;
                                break;
                        }
 
-                       if (!chip->pdata->enable_current_sense &&
-                               volt_ocv <= POWER_SUPPLY_VOLT_MIN_THRESHOLD) {
-                               val->intval = 0;
-                               break;
-                       }
                }
 
                /* Check for LOW Battery Shutdown mechanism is enabled */
                if (chip->pdata->is_lowbatt_shutdown &&
                        (chip->health == POWER_SUPPLY_HEALTH_DEAD)) {
-                       val->intval = 0;
+                       /* if user disables LOWBATT INT shutdown method
+                        * report 1% capcity so that platform
+                        * will not get shutdown.
+                        */
+                       if (chip->disable_shdwn_methods &
+                                       SHUTDOWN_LOWBATT_MASK_BIT)
+                               val->intval = 1;
+                       else
+                               val->intval = 0;
                        break;
                }
 
@@ -655,6 +683,14 @@ static int max17042_get_property(struct power_supply *psy,
 
                if (val->intval > 100)
                        val->intval = 100;
+
+               /* if user disables default FG shutdown method
+                * report 1% capcity so that platform
+                * will not get shutdown.
+                */
+               if ((val->intval == 0) && (chip->disable_shdwn_methods &
+                               SHUTDOWN_DEF_FG_MASK_BIT))
+                       val->intval = 1;
                break;
        default:
                mutex_unlock(&chip->batt_lock);
@@ -1482,6 +1518,44 @@ static inline void max17042_remove_debugfs(struct max17042_chip *chip)
 {
 }
 #endif
+/**
+ * override_shutdown_methods - sysfs to set disable_shdwn_methods
+ * Parameter as define by sysfs interface
+ * Context: can sleep
+ *
+ */
+static ssize_t override_shutdown_methods(struct device *dev,
+                              struct device_attribute *attr, const char *buf,
+                              size_t count)
+{
+       struct max17042_chip *chip = dev_get_drvdata(dev);
+       unsigned long value;
+
+       if (strict_strtoul(buf, 10, &value))
+               return -EINVAL;
+
+       if (value > (SHUTDOWN_DEF_FG_MASK_BIT |
+                       SHUTDOWN_OCV_MASK_BIT |
+                       SHUTDOWN_LOWBATT_MASK_BIT))
+               return -EINVAL;
+
+       chip->disable_shdwn_methods = value;
+       return count;
+}
+
+/**
+ * get_shutdown_methods - sysfs get disable_shdwn_methods
+ * Parameter as define by sysfs interface
+ * Context: can sleep
+ *
+ */
+static ssize_t get_shutdown_methods(struct device *dev,
+                              struct device_attribute *attr, char *buf)
+{
+       struct max17042_chip *chip = dev_get_drvdata(dev);
+
+       return sprintf(buf, "%d\n", chip->disable_shdwn_methods);
+}
 
 static int __devinit max17042_probe(struct i2c_client *client,
                        const struct i2c_device_id *id)
@@ -1633,6 +1707,12 @@ static int __devinit max17042_probe(struct i2c_client *client,
        /* Create debugfs for maxim registers */
        max17042_create_debugfs(chip);
 
+       /* create sysfs file to disable shutdown methods */
+       ret = device_create_file(&client->dev,
+                       &dev_attr_disable_shutdown_methods);
+       if (ret)
+               dev_warn(&client->dev, "cannot create sysfs entry\n");
+
        /* Register reboot notifier callback */
        register_reboot_notifier(&max17042_reboot_notifier_block);
 
@@ -1644,6 +1724,7 @@ static int __devexit max17042_remove(struct i2c_client *client)
        struct max17042_chip *chip = i2c_get_clientdata(client);
 
        unregister_reboot_notifier(&max17042_reboot_notifier_block);
+       device_remove_file(&client->dev, &dev_attr_disable_shutdown_methods);
        max17042_remove_debugfs(chip);
        if (client->irq > 0)
                free_irq(client->irq, chip);