[PATCH v2 03/13] power: bq24257: Allow manual setting of input current limit

Andreas Dannenberg
2015-09-09T00:12:27Z

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>
---
drivers/power/bq24257_charger.c | 100 +++++++++++++++++++++++++++++++---------
1 file changed, 79 insertions(+), 21 deletions(-)

diff --git a/drivers/power/bq24257_charger.c b/drivers/power/bq24257_charger.c
index 670ca57..d83898f 100644
--- a/drivers/power/bq24257_charger.c
+++ b/drivers/power/bq24257_charger.c
@@ -74,6 +74,7 @@ struct bq24257_init_data {
u8 ichg; /* charge current */
u8 vbat; /* regulation voltage */
u8 iterm; /* termination current */
+ u8 in_ilimit; /* input current limit */
};

struct bq24257_state {
@@ -100,6 +101,8 @@ struct bq24257_device {
struct bq24257_state state;

struct mutex lock; /* protect state data */
+
+ bool in_ilimit_autoset_disable;
};

static bool bq24257_is_volatile_reg(struct device *dev, unsigned int reg)
@@ -188,6 +191,12 @@ 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)
{
@@ -479,24 +488,35 @@ static void bq24257_handle_state_change(struct bq24257_device *bq,
old_state = bq->state;
mutex_unlock(&bq->lock);

- if (!new_state->power_good) { /* power removed */
- 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;
+ /*
+ * 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");
+ if (!bq->in_ilimit_autoset_disable) {
+ cancel_delayed_work_sync(&bq->iilimit_setup_work);

- reset_iilimit = true;
- } else if (!old_state.power_good) { /* power inserted */
- config_iilimit = true;
- } else if (new_state->fault == FAULT_NO_BAT) { /* battery removed */
- 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_iilimit = true;
- } else if (old_state.fault == FAULT_NO_BAT) { /* battery connected */
- config_iilimit = true;
- } else if (new_state->fault == FAULT_TIMER) { /* safety timer expired */
+ reset_iilimit = true;
+ }
+ } else if (!old_state.power_good) {
+ dev_dbg(bq->dev, "Power inserted\n");
+ config_iilimit = !bq->in_ilimit_autoset_disable;
+ } else if (new_state->fault == FAULT_NO_BAT) {
+ dev_warn(bq->dev, "Battery removed\n");
+ if (!bq->in_ilimit_autoset_disable) {
+ cancel_delayed_work_sync(&bq->iilimit_setup_work);
+ reset_iilimit = true;
+ }
+ } else if (old_state.fault == FAULT_NO_BAT) {
+ dev_warn(bq->dev, "Battery connected\n");
+ config_iilimit = !bq->in_ilimit_autoset_disable;
+ } else if (new_state->fault == FAULT_TIMER) {
dev_err(bq->dev, "Safety timer expired! Battery dead?\n");
}

@@ -581,7 +601,16 @@ static int bq24257_hw_init(struct bq24257_device *bq)
bq->state = state;
mutex_unlock(&bq->lock);

- if (!state.power_good)
+ if (bq->in_ilimit_autoset_disable) {
+ dev_dbg(bq->dev, "manually setting iilimit = %d\n",
+ bq->init_data.in_ilimit);
+
+ /* program fixed input current limit */
+ ret = bq24257_field_write(bq, F_IILIMIT,
+ bq->init_data.in_ilimit);
+ 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)
@@ -659,6 +688,7 @@ 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;
@@ -682,6 +712,22 @@ 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)
+ /*
+ * 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.in_ilimit = IILIMIT_500;
+ else {
+ bq->in_ilimit_autoset_disable = true;
+ bq->init_data.in_ilimit = bq24257_find_idx(property,
+ bq24257_iilimit_map, BQ24257_IILIMIT_MAP_SIZE);
+ }
+
return 0;
}

@@ -740,8 +786,6 @@ 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) {
@@ -752,6 +796,18 @@ 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->in_ilimit_autoset_disable = true;
+
+ if (!bq->in_ilimit_autoset_disable)
+ 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)
@@ -804,7 +860,8 @@ 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->in_ilimit_autoset_disable)
+ cancel_delayed_work_sync(&bq->iilimit_setup_work);

power_supply_unregister(bq->charger);

@@ -819,7 +876,8 @@ 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->in_ilimit_autoset_disable)
+ 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);
--
1.9.1