power: bq24257: Allow manual setting of input current limit

A new optional device property called "ti,current-limit" is introduced
to allow disabling the D+/D- USB signal-based charger type auto-
detection algorithm used to set the input current limit and instead to
use a fixed input current limit.

Signed-off-by: Andreas Dannenberg <dannenberg@ti.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>

diff --git a/drivers/power/bq24257_charger.c b/drivers/power/bq24257_charger.c
index 93f75820020ad6a1c48ff8c7bf692faa696255ec..7bbff806624f538144e88d5373653e82f10aeac8 100644 (file)
--- a/drivers/power/bq24257_charger.c
+++ b/drivers/power/bq24257_charger.c
@@ -77,6 +77,7 @@ struct bq24257_init_data {
        u8 ichg;        /* charge current      */
        u8 vbat;        /* regulation voltage  */
        u8 iterm;       /* termination current */
+       u8 iilimit;     /* input current limit */
 };
 
 struct bq24257_state {
@@ -103,6 +104,8 @@ struct bq24257_device {
        struct bq24257_state state;
 
        struct mutex lock; /* protect state data */
+
+       bool iilimit_autoset_enable;
 };
 
 static bool bq24257_is_volatile_reg(struct device *dev, unsigned int reg)
@@ -191,6 +194,12 @@ static const u32 bq24257_iterm_map[] = {
 
 #define BQ24257_ITERM_MAP_SIZE         ARRAY_SIZE(bq24257_iterm_map)
 
+static const u32 bq24257_iilimit_map[] = {
+       100000, 150000, 500000, 900000, 1500000, 2000000
+};
+
+#define BQ24257_IILIMIT_MAP_SIZE       ARRAY_SIZE(bq24257_iilimit_map)
+
 static int bq24257_field_read(struct bq24257_device *bq,
                              enum bq24257_fields field_id)
 {
@@ -480,24 +489,32 @@ static void bq24257_handle_state_change(struct bq24257_device *bq,
        old_state = bq->state;
        mutex_unlock(&bq->lock);
 
+       /*
+        * Handle BQ2425x state changes observing whether the D+/D- based input
+        * current limit autoset functionality is enabled.
+        */
        if (!new_state->power_good) {
                dev_dbg(bq->dev, "Power removed\n");
-               cancel_delayed_work_sync(&bq->iilimit_setup_work);
-
-               /* activate D+/D- port detection algorithm */
-               ret = bq24257_field_write(bq, F_DPDM_EN, 1);
-               if (ret < 0)
-                       goto error;
-
-               /* reset input current limit */
-               ret = bq24257_field_write(bq, F_IILIMIT, IILIMIT_500);
-               if (ret < 0)
-                       goto error;
+               if (bq->iilimit_autoset_enable) {
+                       cancel_delayed_work_sync(&bq->iilimit_setup_work);
+
+                       /* activate D+/D- port detection algorithm */
+                       ret = bq24257_field_write(bq, F_DPDM_EN, 1);
+                       if (ret < 0)
+                               goto error;
+
+                       /* reset input current limit */
+                       ret = bq24257_field_write(bq, F_IILIMIT,
+                                                 bq->init_data.iilimit);
+                       if (ret < 0)
+                               goto error;
+               }
        } else if (!old_state.power_good) {
                dev_dbg(bq->dev, "Power inserted\n");
 
-               /* configure input current limit */
-               schedule_delayed_work(&bq->iilimit_setup_work,
+               if (bq->iilimit_autoset_enable)
+                       /* configure input current limit */
+                       schedule_delayed_work(&bq->iilimit_setup_work,
                                      msecs_to_jiffies(BQ24257_ILIM_SET_DELAY));
        } else if (new_state->fault == FAULT_NO_BAT) {
                dev_warn(bq->dev, "Battery removed\n");
@@ -577,7 +594,16 @@ static int bq24257_hw_init(struct bq24257_device *bq)
        bq->state = state;
        mutex_unlock(&bq->lock);
 
-       if (!state.power_good)
+       if (!bq->iilimit_autoset_enable) {
+               dev_dbg(bq->dev, "manually setting iilimit = %u\n",
+                       bq->init_data.iilimit);
+
+               /* program fixed input current limit */
+               ret = bq24257_field_write(bq, F_IILIMIT,
+                                         bq->init_data.iilimit);
+               if (ret < 0)
+                       return ret;
+       } else if (!state.power_good)
                /* activate D+/D- detection algorithm */
                ret = bq24257_field_write(bq, F_DPDM_EN, 1);
        else if (state.fault != FAULT_NO_BAT)
@@ -641,6 +667,7 @@ static int bq24257_fw_probe(struct bq24257_device *bq)
        int ret;
        u32 property;
 
+       /* Required properties */
        ret = device_property_read_u32(bq->dev, "ti,charge-current", &property);
        if (ret < 0)
                return ret;
@@ -664,6 +691,24 @@ static int bq24257_fw_probe(struct bq24257_device *bq)
        bq->init_data.iterm = bq24257_find_idx(property, bq24257_iterm_map,
                                               BQ24257_ITERM_MAP_SIZE);
 
+       /* Optional properties. If not provided use reasonable default. */
+       ret = device_property_read_u32(bq->dev, "ti,current-limit",
+                                      &property);
+       if (ret < 0) {
+               bq->iilimit_autoset_enable = true;
+
+               /*
+                * Explicitly set a default value which will be needed for
+                * devices that don't support the automatic setting of the input
+                * current limit through the charger type detection mechanism.
+                */
+               bq->init_data.iilimit = IILIMIT_500;
+       } else
+               bq->init_data.iilimit =
+                               bq24257_find_idx(property,
+                                                bq24257_iilimit_map,
+                                                BQ24257_IILIMIT_MAP_SIZE);
+
        return 0;
 }
 
@@ -722,8 +767,6 @@ static int bq24257_probe(struct i2c_client *client,
 
        i2c_set_clientdata(client, bq);
 
-       INIT_DELAYED_WORK(&bq->iilimit_setup_work, bq24257_iilimit_setup_work);
-
        if (!dev->platform_data) {
                ret = bq24257_fw_probe(bq);
                if (ret < 0) {
@@ -734,6 +777,18 @@ static int bq24257_probe(struct i2c_client *client,
                return -ENODEV;
        }
 
+       /*
+        * The BQ24250 doesn't support the D+/D- based charger type detection
+        * used for the automatic setting of the input current limit setting so
+        * explicitly disable that feature.
+        */
+       if (bq->chip == BQ24250)
+               bq->iilimit_autoset_enable = false;
+
+       if (bq->iilimit_autoset_enable)
+               INIT_DELAYED_WORK(&bq->iilimit_setup_work,
+                                 bq24257_iilimit_setup_work);
+
        /* we can only check Power Good status by probing the PG pin */
        ret = bq24257_pg_gpio_probe(bq);
        if (ret < 0)
@@ -780,7 +835,8 @@ static int bq24257_remove(struct i2c_client *client)
 {
        struct bq24257_device *bq = i2c_get_clientdata(client);
 
-       cancel_delayed_work_sync(&bq->iilimit_setup_work);
+       if (bq->iilimit_autoset_enable)
+               cancel_delayed_work_sync(&bq->iilimit_setup_work);
 
        bq24257_field_write(bq, F_RESET, 1); /* reset to defaults */
 
@@ -793,7 +849,8 @@ static int bq24257_suspend(struct device *dev)
        struct bq24257_device *bq = dev_get_drvdata(dev);
        int ret = 0;
 
-       cancel_delayed_work_sync(&bq->iilimit_setup_work);
+       if (bq->iilimit_autoset_enable)
+               cancel_delayed_work_sync(&bq->iilimit_setup_work);
 
        /* reset all registers to default (and activate standalone mode) */
        ret = bq24257_field_write(bq, F_RESET, 1);