power: supply: ab8500: Drop BATCTRL thermal mode

The BATCTRL mode reads the temperature of the battery by
enabling a certain probing current (7-20 mA) and then measure
the voltage of the NTC mounted inside the battery.

None of the AB8500 product or the reference designs use this
mode. What we use is the so-called BATTEMP mode which enables
an internal 230 kOhm pull-up to 1.8 V to the external NTC on
pin BatTemp (N16) and then measures the voltage over the NTC
using the ADC:

        1.8V (VTVOUT)
         |
        [ ] 230 kOhm
         |
BatTemp  +---------------- ADC
Pin N16  | _
         |/
        [/] NTC
       _/|
         |
        GND

Cut out the BATCTRL code to clear the forest and stop
maintaining code we can never test.

The current inducing method is still used to probe for the
battery type using the internal BTI (battery type indicator)
on the BatCtrl (C3) pin in a separate code path.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

1 files changed, 24 insertions, 239 deletions

diff --git a/drivers/power/supply/ab8500_btemp.c b/drivers/power/supply/ab8500_btemp.c
index cc33c5187fbb..a5ca09124c93 100644
--- a/drivers/power/supply/ab8500_btemp.c
+++ b/drivers/power/supply/ab8500_btemp.c
@@ -135,8 +135,6 @@ static LIST_HEAD(ab8500_btemp_list);
 static int ab8500_btemp_batctrl_volt_to_res(struct ab8500_btemp *di,
 	int v_batctrl, int inst_curr)
 {
-	int rbs;
-
 	if (is_ab8500_1p1_or_earlier(di->parent)) {
 		/*
 		 * For ABB cut1.0 and 1.1 BAT_CTRL is internally
@@ -145,23 +143,11 @@ static int ab8500_btemp_batctrl_volt_to_res(struct ab8500_btemp *di,
 		return (450000 * (v_batctrl)) / (1800 - v_batctrl);
 	}
 
-	if (di->bm->adc_therm == AB8500_ADC_THERM_BATCTRL) {
-		/*
-		 * If the battery has internal NTC, we use the current
-		 * source to calculate the resistance.
-		 */
-		rbs = (v_batctrl * 1000
-		       - di->bm->gnd_lift_resistance * inst_curr)
-		      / di->curr_source;
-	} else {
-		/*
-		 * BAT_CTRL is internally
-		 * connected to 1.8V through a 80k resistor
-		 */
-		rbs = (80000 * (v_batctrl)) / (1800 - v_batctrl);
-	}
-
-	return rbs;
+	/*
+	 * BAT_CTRL is internally
+	 * connected to 1.8V through a 80k resistor
+	 */
+	return (80000 * (v_batctrl)) / (1800 - v_batctrl);
 }
 
 /**
@@ -187,155 +173,6 @@ static int ab8500_btemp_read_batctrl_voltage(struct ab8500_btemp *di)
 }
 
 /**
- * ab8500_btemp_curr_source_enable() - enable/disable batctrl current source
- * @di:		pointer to the ab8500_btemp structure
- * @enable:	enable or disable the current source
- *
- * Enable or disable the current sources for the BatCtrl AD channel
- */
-static int ab8500_btemp_curr_source_enable(struct ab8500_btemp *di,
-	bool enable)
-{
-	int curr;
-	int ret = 0;
-
-	/*
-	 * BATCTRL current sources are included on AB8500 cut2.0
-	 * and future versions
-	 */
-	if (is_ab8500_1p1_or_earlier(di->parent))
-		return 0;
-
-	/* Only do this for batteries with internal NTC */
-	if (di->bm->adc_therm == AB8500_ADC_THERM_BATCTRL && enable) {
-
-		if (di->curr_source == BTEMP_BATCTRL_CURR_SRC_7UA)
-			curr = BAT_CTRL_7U_ENA;
-		else
-			curr = BAT_CTRL_20U_ENA;
-
-		dev_dbg(di->dev, "Set BATCTRL %duA\n", di->curr_source);
-
-		ret = abx500_mask_and_set_register_interruptible(di->dev,
-			AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
-			FORCE_BAT_CTRL_CMP_HIGH, FORCE_BAT_CTRL_CMP_HIGH);
-		if (ret) {
-			dev_err(di->dev, "%s failed setting cmp_force\n",
-				__func__);
-			return ret;
-		}
-
-		/*
-		 * We have to wait one 32kHz cycle before enabling
-		 * the current source, since ForceBatCtrlCmpHigh needs
-		 * to be written in a separate cycle
-		 */
-		udelay(32);
-
-		ret = abx500_set_register_interruptible(di->dev,
-			AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
-			FORCE_BAT_CTRL_CMP_HIGH | curr);
-		if (ret) {
-			dev_err(di->dev, "%s failed enabling current source\n",
-				__func__);
-			goto disable_curr_source;
-		}
-	} else if (di->bm->adc_therm == AB8500_ADC_THERM_BATCTRL && !enable) {
-		dev_dbg(di->dev, "Disable BATCTRL curr source\n");
-
-		/* Write 0 to the curr bits */
-		ret = abx500_mask_and_set_register_interruptible(
-			di->dev,
-			AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
-			BAT_CTRL_7U_ENA | BAT_CTRL_20U_ENA,
-			~(BAT_CTRL_7U_ENA | BAT_CTRL_20U_ENA));
-
-		if (ret) {
-			dev_err(di->dev, "%s failed disabling current source\n",
-				__func__);
-			goto disable_curr_source;
-		}
-
-		/* Enable Pull-Up and comparator */
-		ret = abx500_mask_and_set_register_interruptible(di->dev,
-			AB8500_CHARGER,	AB8500_BAT_CTRL_CURRENT_SOURCE,
-			BAT_CTRL_PULL_UP_ENA | BAT_CTRL_CMP_ENA,
-			BAT_CTRL_PULL_UP_ENA | BAT_CTRL_CMP_ENA);
-		if (ret) {
-			dev_err(di->dev, "%s failed enabling PU and comp\n",
-				__func__);
-			goto enable_pu_comp;
-		}
-
-		/*
-		 * We have to wait one 32kHz cycle before disabling
-		 * ForceBatCtrlCmpHigh since this needs to be written
-		 * in a separate cycle
-		 */
-		udelay(32);
-
-		/* Disable 'force comparator' */
-		ret = abx500_mask_and_set_register_interruptible(di->dev,
-			AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
-			FORCE_BAT_CTRL_CMP_HIGH, ~FORCE_BAT_CTRL_CMP_HIGH);
-		if (ret) {
-			dev_err(di->dev, "%s failed disabling force comp\n",
-				__func__);
-			goto disable_force_comp;
-		}
-	}
-	return ret;
-
-	/*
-	 * We have to try unsetting FORCE_BAT_CTRL_CMP_HIGH one more time
-	 * if we got an error above
-	 */
-disable_curr_source:
-	/* Write 0 to the curr bits */
-	ret = abx500_mask_and_set_register_interruptible(di->dev,
-		AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
-		BAT_CTRL_7U_ENA | BAT_CTRL_20U_ENA,
-		~(BAT_CTRL_7U_ENA | BAT_CTRL_20U_ENA));
-
-	if (ret) {
-		dev_err(di->dev, "%s failed disabling current source\n",
-			__func__);
-		return ret;
-	}
-enable_pu_comp:
-	/* Enable Pull-Up and comparator */
-	ret = abx500_mask_and_set_register_interruptible(di->dev,
-		AB8500_CHARGER,	AB8500_BAT_CTRL_CURRENT_SOURCE,
-		BAT_CTRL_PULL_UP_ENA | BAT_CTRL_CMP_ENA,
-		BAT_CTRL_PULL_UP_ENA | BAT_CTRL_CMP_ENA);
-	if (ret) {
-		dev_err(di->dev, "%s failed enabling PU and comp\n",
-			__func__);
-		return ret;
-	}
-
-disable_force_comp:
-	/*
-	 * We have to wait one 32kHz cycle before disabling
-	 * ForceBatCtrlCmpHigh since this needs to be written
-	 * in a separate cycle
-	 */
-	udelay(32);
-
-	/* Disable 'force comparator' */
-	ret = abx500_mask_and_set_register_interruptible(di->dev,
-		AB8500_CHARGER, AB8500_BAT_CTRL_CURRENT_SOURCE,
-		FORCE_BAT_CTRL_CMP_HIGH, ~FORCE_BAT_CTRL_CMP_HIGH);
-	if (ret) {
-		dev_err(di->dev, "%s failed disabling force comp\n",
-			__func__);
-		return ret;
-	}
-
-	return ret;
-}
-
-/**
  * ab8500_btemp_get_batctrl_res() - get battery resistance
  * @di:		pointer to the ab8500_btemp structure
  *
@@ -350,16 +187,6 @@ static int ab8500_btemp_get_batctrl_res(struct ab8500_btemp *di)
 	int inst_curr;
 	int i;
 
-	/*
-	 * BATCTRL current sources are included on AB8500 cut2.0
-	 * and future versions
-	 */
-	ret = ab8500_btemp_curr_source_enable(di, true);
-	if (ret) {
-		dev_err(di->dev, "%s curr source enabled failed\n", __func__);
-		return ret;
-	}
-
 	if (!di->fg)
 		di->fg = ab8500_fg_get();
 	if (!di->fg) {
@@ -395,12 +222,6 @@ static int ab8500_btemp_get_batctrl_res(struct ab8500_btemp *di)
 
 	res = ab8500_btemp_batctrl_volt_to_res(di, batctrl, inst_curr);
 
-	ret = ab8500_btemp_curr_source_enable(di, false);
-	if (ret) {
-		dev_err(di->dev, "%s curr source disable failed\n", __func__);
-		return ret;
-	}
-
 	dev_dbg(di->dev, "%s batctrl: %d res: %d inst_curr: %d samples: %d\n",
 		__func__, batctrl, res, inst_curr, i);
 
@@ -451,47 +272,28 @@ static int ab8500_btemp_res_to_temp(struct ab8500_btemp *di,
  */
 static int ab8500_btemp_measure_temp(struct ab8500_btemp *di)
 {
-	struct power_supply_battery_info *bi = di->bm->bi;
 	int temp, ret;
 	static int prev;
-	int rbat, rntc, vntc;
-
-	if ((di->bm->adc_therm == AB8500_ADC_THERM_BATCTRL) &&
-	    (bi && (bi->technology == POWER_SUPPLY_TECHNOLOGY_UNKNOWN))) {
-
-		rbat = ab8500_btemp_get_batctrl_res(di);
-		if (rbat < 0) {
-			dev_err(di->dev, "%s get batctrl res failed\n",
-				__func__);
-			/*
-			 * Return out-of-range temperature so that
-			 * charging is stopped
-			 */
-			return BTEMP_THERMAL_LOW_LIMIT;
-		}
-
-		temp = ab8500_btemp_res_to_temp(di,
-			di->bm->bat_type->r_to_t_tbl,
-			di->bm->bat_type->n_temp_tbl_elements, rbat);
-	} else {
-		ret = iio_read_channel_processed(di->btemp_ball, &vntc);
-		if (ret < 0) {
-			dev_err(di->dev,
-				"%s ADC conversion failed,"
-				" using previous value\n", __func__);
-			return prev;
-		}
-		/*
-		 * The PCB NTC is sourced from VTVOUT via a 230kOhm
-		 * resistor.
-		 */
-		rntc = 230000 * vntc / (VTVOUT_V - vntc);
+	int rntc, vntc;
 
-		temp = ab8500_btemp_res_to_temp(di,
-			di->bm->bat_type->r_to_t_tbl,
-			di->bm->bat_type->n_temp_tbl_elements, rntc);
-		prev = temp;
+	ret = iio_read_channel_processed(di->btemp_ball, &vntc);
+	if (ret < 0) {
+		dev_err(di->dev,
+			"%s ADC conversion failed,"
+			" using previous value\n", __func__);
+		return prev;
 	}
+	/*
+	 * The PCB NTC is sourced from VTVOUT via a 230kOhm
+	 * resistor.
+	 */
+	rntc = 230000 * vntc / (VTVOUT_V - vntc);
+
+	temp = ab8500_btemp_res_to_temp(di,
+		di->bm->bat_type->r_to_t_tbl,
+		di->bm->bat_type->n_temp_tbl_elements, rntc);
+	prev = temp;
+
 	dev_dbg(di->dev, "Battery temperature is %d\n", temp);
 	return temp;
 }
@@ -519,11 +321,9 @@ static int ab8500_btemp_id(struct ab8500_btemp *di)
 
 	if ((res <= di->bm->bat_type->resis_high) &&
 	    (res >= di->bm->bat_type->resis_low)) {
-		dev_info(di->dev, "Battery detected on %s"
+		dev_info(di->dev, "Battery detected on BATTEMP"
 			 " low %d < res %d < high: %d"
 			 " index: %d\n",
-			 di->bm->adc_therm == AB8500_ADC_THERM_BATCTRL ?
-			 "BATCTRL" : "BATTEMP",
 			 di->bm->bat_type->resis_low, res,
 			 di->bm->bat_type->resis_high, i);
 	} else {
@@ -532,21 +332,6 @@ static int ab8500_btemp_id(struct ab8500_btemp *di)
 		return -ENXIO;
 	}
 
-	/*
-	 * We only have to change current source if the
-	 * detected type is Type 1 (LIPO) resis_high = 53407, resis_low = 12500
-	 * if someone hacks this in.
-	 *
-	 * FIXME: make sure this is done automatically for the batteries
-	 * that need it.
-	 */
-	if ((di->bm->adc_therm == AB8500_ADC_THERM_BATCTRL) &&
-	    (di->bm->bi && (di->bm->bi->technology == POWER_SUPPLY_TECHNOLOGY_LIPO)) &&
-	    (res <= 53407) && (res >= 12500)) {
-		dev_dbg(di->dev, "Set BATCTRL current source to 20uA\n");
-		di->curr_source = BTEMP_BATCTRL_CURR_SRC_20UA;
-	}
-
 	return 0;
 }