smb138x-charger: configure connector temp thresholds

Add a device tree property qcom,connector-temp-max-mdegc to configure
the connector temperature at which mitigation should start.

This will set the thresholds for when the temperature-change IRQ will
fire.

Change-Id: I47df477b56a6654fbf94b5bb0f7dfdfb80e2f16e
Signed-off-by: Nicholas Troast <ntroast@codeaurora.org>

Documentation/devicetree/bindings/power/supply/qcom/smb138x-charger.txt

@@ -58,6 +58,12 @@ Charger specific properties:
   Definition: Specifies the maximum charger temperature in milli-degrees
 	      Celsius. If unspecified a default of 80000 will be used.
 
+- qcom,connector-temp-max-mdegc
+  Usage:      optional
+  Value type: <u32>
+  Definition: Specifies the maximum connector temperature in milli-degrees
+	      Celsius. If unspecified a default value of 105000 will be used.
+
 - io-channels
   Usage:      optional
   Value type: List of <phandle u32>

drivers/power/supply/qcom/smb-lib.h

@@ -135,6 +135,9 @@ struct smb_iio {
 	struct iio_channel	*usbin_i_chan;
 	struct iio_channel	*usbin_v_chan;
 	struct iio_channel	*batt_i_chan;
+	struct iio_channel	*connector_temp_thr1_chan;
+	struct iio_channel	*connector_temp_thr2_chan;
+	struct iio_channel	*connector_temp_thr3_chan;
 };
 
 struct reg_info {

drivers/power/supply/qcom/smb138x-charger.c

@@ -93,6 +93,7 @@ struct smb_dt_props {
 	int	usb_icl_ua;
 	int	dc_icl_ua;
 	int	chg_temp_max_mdegc;
+	int	connector_temp_max_mdegc;
 };
 
 struct smb138x {
@@ -142,6 +143,12 @@ static int smb138x_parse_dt(struct smb138x *chip)
 	if (rc < 0)
 		chip->dt.chg_temp_max_mdegc = 80000;
 
+	rc = of_property_read_u32(node,
+				"qcom,connector-temp-max-mdegc",
+				&chip->dt.chg_temp_max_mdegc);
+	if (rc < 0)
+		chip->dt.connector_temp_max_mdegc = 105000;
+
 	return 0;
 }
 
@@ -672,6 +679,8 @@ static int smb138x_init_vconn_regulator(struct smb138x *chip)
  * HARDWARE INITIALIZATION *
  ***************************/
 
+#define MDEGC_3		3000
+#define MDEGC_15	15000
 static int smb138x_init_slave_hw(struct smb138x *chip)
 {
 	struct smb_charger *chg = &chip->chg;
@@ -771,6 +780,26 @@ static int smb138x_init_slave_hw(struct smb138x *chip)
 		return rc;
 	}
 
+	rc = iio_write_channel_processed(chg->iio.connector_temp_thr1_chan,
+				chip->dt.connector_temp_max_mdegc);
+	if (rc < 0) {
+		pr_err("Couldn't set connector temp threshold1 rc=%d\n", rc);
+		return rc;
+	}
+
+	rc = iio_write_channel_processed(chg->iio.connector_temp_thr2_chan,
+				chip->dt.connector_temp_max_mdegc + MDEGC_3);
+	if (rc < 0) {
+		pr_err("Couldn't set connector temp threshold2 rc=%d\n", rc);
+		return rc;
+	}
+
+	rc = iio_write_channel_processed(chg->iio.connector_temp_thr3_chan,
+				chip->dt.connector_temp_max_mdegc + MDEGC_15);
+	if (rc < 0) {
+		pr_err("Couldn't set connector temp threshold3 rc=%d\n", rc);
+		return rc;
+	}
 	return 0;
 }
 
@@ -1277,6 +1306,27 @@ static int smb138x_slave_probe(struct smb138x *chip)
 		goto cleanup;
 	}
 
+	chg->iio.connector_temp_thr1_chan = iio_channel_get(chg->dev,
+							"connector_temp_thr1");
+	if (IS_ERR(chg->iio.connector_temp_thr1_chan)) {
+		rc = PTR_ERR(chg->iio.connector_temp_thr1_chan);
+		goto cleanup;
+	}
+
+	chg->iio.connector_temp_thr2_chan = iio_channel_get(chg->dev,
+							"connector_temp_thr2");
+	if (IS_ERR(chg->iio.connector_temp_thr2_chan)) {
+		rc = PTR_ERR(chg->iio.connector_temp_thr2_chan);
+		goto cleanup;
+	}
+
+	chg->iio.connector_temp_thr3_chan = iio_channel_get(chg->dev,
+							"connector_temp_thr3");
+	if (IS_ERR(chg->iio.connector_temp_thr3_chan)) {
+		rc = PTR_ERR(chg->iio.connector_temp_thr3_chan);
+		goto cleanup;
+	}
+
 	rc = smb138x_parse_dt(chip);
 	if (rc < 0) {
 		pr_err("Couldn't parse device tree rc=%d\n", rc);