bq20z75: Add optional battery detect gpio

Adding support for an optional gpio for battery detection. This is
passed in through the i2c platform data. It also accepts another
field, battery_detect_present to signify the gpio state which means
the battery is present, either 0 (low) or 1 (high).

Signed-off-by: Rhyland Klein <rklein@nvidia.com>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>

2 files changed, 166 insertions, 31 deletions

diff --git a/drivers/power/bq20z75.c b/drivers/power/bq20z75.c
index 4141775e5ff6..a51e98d74d34 100644
--- a/drivers/power/bq20z75.c
+++ b/drivers/power/bq20z75.c
@@ -25,6 +25,10 @@
 #include <linux/power_supply.h>
 #include <linux/i2c.h>
 #include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/gpio.h>
+
+#include <linux/power/bq20z75.h>
 
 enum {
         REG_MANUFACTURER_DATA,
@@ -141,8 +145,13 @@ static enum power_supply_property bq20z75_properties[] = {
 };
 
 struct bq20z75_info {
-        struct i2c_client       *client;
-        struct power_supply     power_supply;
+        struct i2c_client               *client;
+        struct power_supply             power_supply;
+        struct bq20z75_platform_data    *pdata;
+        bool                            is_present;
+        bool                            gpio_detect;
+        bool                            enable_detection;
+        int                             irq;
 };
 
 static int bq20z75_read_word_data(struct i2c_client *client, u8 address)
@@ -179,6 +188,18 @@ static int bq20z75_get_battery_presence_and_health(
         union power_supply_propval *val)
 {
         s32 ret;
+        struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
+
+        if (psp == POWER_SUPPLY_PROP_PRESENT &&
+                bq20z75_device->gpio_detect) {
+                ret = gpio_get_value(
+                        bq20z75_device->pdata->battery_detect);
+                if (ret == bq20z75_device->pdata->battery_detect_present)
+                        val->intval = 1;
+                else
+                        val->intval = 0;
+                return ret;
+        }
 
         /* Write to ManufacturerAccess with
          * ManufacturerAccess command and then
@@ -192,8 +213,11 @@ static int bq20z75_get_battery_presence_and_health(
 
         ret = bq20z75_read_word_data(client,
                 bq20z75_data[REG_MANUFACTURER_DATA].addr);
-        if (ret < 0)
+        if (ret < 0) {
+                if (psp == POWER_SUPPLY_PROP_PRESENT)
+                        val->intval = 0; /* battery removed */
                 return ret;
+        }
 
         if (ret < bq20z75_data[REG_MANUFACTURER_DATA].min_value ||
             ret > bq20z75_data[REG_MANUFACTURER_DATA].max_value) {
@@ -397,8 +421,7 @@ static int bq20z75_get_property(struct power_supply *psy,
         enum power_supply_property psp,
         union power_supply_propval *val)
 {
-        int ps_index;
-        int ret;
+        int ret = 0;
         struct bq20z75_info *bq20z75_device = container_of(psy,
                                 struct bq20z75_info, power_supply);
         struct i2c_client *client = bq20z75_device->client;
@@ -407,8 +430,6 @@ static int bq20z75_get_property(struct power_supply *psy,
         case POWER_SUPPLY_PROP_PRESENT:
         case POWER_SUPPLY_PROP_HEALTH:
                 ret = bq20z75_get_battery_presence_and_health(client, psp, val);
-                if (ret)
-                        return ret;
                 break;
 
         case POWER_SUPPLY_PROP_TECHNOLOGY:
@@ -422,20 +443,15 @@ static int bq20z75_get_property(struct power_supply *psy,
         case POWER_SUPPLY_PROP_CHARGE_FULL:
         case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
         case POWER_SUPPLY_PROP_CAPACITY:
-                ps_index = bq20z75_get_property_index(client, psp);
-                if (ps_index < 0)
-                        return ps_index;
-
-                ret = bq20z75_get_battery_capacity(client, ps_index, psp, val);
-                if (ret)
-                        return ret;
+                ret = bq20z75_get_property_index(client, psp);
+                if (ret < 0)
+                        break;
 
+                ret = bq20z75_get_battery_capacity(client, ret, psp, val);
                 break;
 
         case POWER_SUPPLY_PROP_SERIAL_NUMBER:
                 ret = bq20z75_get_battery_serial_number(client, val);
-                if (ret)
-                        return ret;
                 break;
 
         case POWER_SUPPLY_PROP_STATUS:
@@ -446,14 +462,11 @@ static int bq20z75_get_property(struct power_supply *psy,
         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
         case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
         case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
-                ps_index = bq20z75_get_property_index(client, psp);
-                if (ps_index < 0)
-                        return ps_index;
-
-                ret = bq20z75_get_battery_property(client, ps_index, psp, val);
-                if (ret)
-                        return ret;
+                ret = bq20z75_get_property_index(client, psp);
+                if (ret < 0)
+                        break;
 
+                ret = bq20z75_get_battery_property(client, ret, psp, val);
                 break;
 
         default:
@@ -462,26 +475,51 @@ static int bq20z75_get_property(struct power_supply *psy,
                 return -EINVAL;
         }
 
-        /* Convert units to match requirements for power supply class */
-        bq20z75_unit_adjustment(client, psp, val);
+        if (!bq20z75_device->enable_detection)
+                goto done;
+
+        if (!bq20z75_device->gpio_detect &&
+                bq20z75_device->is_present != (ret >= 0)) {
+                bq20z75_device->is_present = (ret >= 0);
+                power_supply_changed(&bq20z75_device->power_supply);
+        }
+
+done:
+        if (!ret) {
+                /* Convert units to match requirements for power supply class */
+                bq20z75_unit_adjustment(client, psp, val);
+        }
 
         dev_dbg(&client->dev,
                 "%s: property = %d, value = %d\n", __func__, psp, val->intval);
 
-        return 0;
+        return ret;
 }
 
-static int bq20z75_probe(struct i2c_client *client,
+static irqreturn_t bq20z75_irq(int irq, void *devid)
+{
+        struct power_supply *battery = devid;
+
+        power_supply_changed(battery);
+
+        return IRQ_HANDLED;
+}
+
+static int __devinit bq20z75_probe(struct i2c_client *client,
         const struct i2c_device_id *id)
 {
         struct bq20z75_info *bq20z75_device;
+        struct bq20z75_platform_data *pdata = client->dev.platform_data;
         int rc;
+        int irq;