Merge tag 'extcon-next-for-5.6' of...

Merge tag 'extcon-next-for-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/extcon into char-misc-next

Chanwoo writes:

Update extcon for 5.6

Detailed description for this pull request:
1. Remove unneeded 'extern' keyword from extcon.h header file
2. Clean-up the extcon provider
- Clean-up the code for readability of extcon-arizona/sm5502.c

* tag 'extcon-next-for-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/extcon:
  extcon: Remove unneeded extern keyword from extcon.h
  extcon: sm5502: Remove unneeded semicolon
  extcon: arizona: Factor out microphone and button detection
  extcon: arizona: Factor out microphone impedance into a function
  extcon: arizona: Invert logic of check in arizona_hpdet_do_id
  extcon: arizona: Remove excessive WARN_ON
  extcon: arizona: Remove unnecessary sets of ACCDET_MODE
  extcon: arizona: Tidy up transition from mic to headphone detect
  extcon: arizona: Clear jack status regardless of detection type
  extcon: arizona: Move pdata extraction to probe
  extcon: arizona: Make rev A register sequences atomic
  extcon: arizona: Correct clean up if arizona_identify_headphone fails

drivers/extcon/extcon-arizona.c

@@ -77,8 +77,6 @@ struct arizona_extcon_info {
 	const struct arizona_micd_range *micd_ranges;
 	int num_micd_ranges;
 
-	int micd_timeout;
-
 	bool micd_reva;
 	bool micd_clamp;
 
@@ -310,9 +308,13 @@ static void arizona_start_mic(struct arizona_extcon_info *info)
 	}
 
 	if (info->micd_reva) {
-		regmap_write(arizona->regmap, 0x80, 0x3);
-		regmap_write(arizona->regmap, 0x294, 0);
-		regmap_write(arizona->regmap, 0x80, 0x0);
+		const struct reg_sequence reva[] = {
+			{ 0x80,  0x3 },
+			{ 0x294, 0x0 },
+			{ 0x80,  0x0 },
+		};
+
+		regmap_multi_reg_write(arizona->regmap, reva, ARRAY_SIZE(reva));
 	}
 
 	if (info->detecting && arizona->pdata.micd_software_compare)
@@ -361,9 +363,13 @@ static void arizona_stop_mic(struct arizona_extcon_info *info)
 	snd_soc_dapm_sync(dapm);
 
 	if (info->micd_reva) {
-		regmap_write(arizona->regmap, 0x80, 0x3);
-		regmap_write(arizona->regmap, 0x294, 2);
-		regmap_write(arizona->regmap, 0x80, 0x0);
+		const struct reg_sequence reva[] = {
+			{ 0x80,  0x3 },
+			{ 0x294, 0x2 },
+			{ 0x80,  0x0 },
+		};
+
+		regmap_multi_reg_write(arizona->regmap, reva, ARRAY_SIZE(reva));
 	}
 
 	ret = regulator_allow_bypass(info->micvdd, true);
@@ -527,67 +533,65 @@ static int arizona_hpdet_do_id(struct arizona_extcon_info *info, int *reading,
 	struct arizona *arizona = info->arizona;
 	int id_gpio = arizona->pdata.hpdet_id_gpio;
 
+	if (!arizona->pdata.hpdet_acc_id)
+		return 0;
+
 	/*
 	 * If we're using HPDET for accessory identification we need
 	 * to take multiple measurements, step through them in sequence.
 	 */
-	if (arizona->pdata.hpdet_acc_id) {
-		info->hpdet_res[info->num_hpdet_res++] = *reading;
+	info->hpdet_res[info->num_hpdet_res++] = *reading;
 
-		/* Only check the mic directly if we didn't already ID it */
-		if (id_gpio && info->num_hpdet_res == 1) {
-			dev_dbg(arizona->dev, "Measuring mic\n");
+	/* Only check the mic directly if we didn't already ID it */
+	if (id_gpio && info->num_hpdet_res == 1) {
+		dev_dbg(arizona->dev, "Measuring mic\n");
 
-			regmap_update_bits(arizona->regmap,
-					   ARIZONA_ACCESSORY_DETECT_MODE_1,
-					   ARIZONA_ACCDET_MODE_MASK |
-					   ARIZONA_ACCDET_SRC,
-					   ARIZONA_ACCDET_MODE_HPR |
-					   info->micd_modes[0].src);
+		regmap_update_bits(arizona->regmap,
+				   ARIZONA_ACCESSORY_DETECT_MODE_1,
+				   ARIZONA_ACCDET_MODE_MASK |
+				   ARIZONA_ACCDET_SRC,
+				   ARIZONA_ACCDET_MODE_HPR |
+				   info->micd_modes[0].src);
 
-			gpio_set_value_cansleep(id_gpio, 1);
+		gpio_set_value_cansleep(id_gpio, 1);
 
-			regmap_update_bits(arizona->regmap,
-					   ARIZONA_HEADPHONE_DETECT_1,
-					   ARIZONA_HP_POLL, ARIZONA_HP_POLL);
-			return -EAGAIN;
-		}
-
-		/* OK, got both.  Now, compare... */
-		dev_dbg(arizona->dev, "HPDET measured %d %d\n",
-			info->hpdet_res[0], info->hpdet_res[1]);
+		regmap_update_bits(arizona->regmap, ARIZONA_HEADPHONE_DETECT_1,
+				   ARIZONA_HP_POLL, ARIZONA_HP_POLL);
+		return -EAGAIN;
+	}
 
-		/* Take the headphone impedance for the main report */
-		*reading = info->hpdet_res[0];
+	/* OK, got both.  Now, compare... */
+	dev_dbg(arizona->dev, "HPDET measured %d %d\n",
+		info->hpdet_res[0], info->hpdet_res[1]);
 
-		/* Sometimes we get false readings due to slow insert */
-		if (*reading >= ARIZONA_HPDET_MAX && !info->hpdet_retried) {
-			dev_dbg(arizona->dev, "Retrying high impedance\n");
-			info->num_hpdet_res = 0;
-			info->hpdet_retried = true;
-			arizona_start_hpdet_acc_id(info);
-			pm_runtime_put(info->dev);
-			return -EAGAIN;
-		}
+	/* Take the headphone impedance for the main report */
+	*reading = info->hpdet_res[0];
 
-		/*
-		 * If we measure the mic as high impedance
-		 */
-		if (!id_gpio || info->hpdet_res[1] > 50) {
-			dev_dbg(arizona->dev, "Detected mic\n");
-			*mic = true;
-			info->detecting = true;
-		} else {
-			dev_dbg(arizona->dev, "Detected headphone\n");
-		}
+	/* Sometimes we get false readings due to slow insert */
+	if (*reading >= ARIZONA_HPDET_MAX && !info->hpdet_retried) {
+		dev_dbg(arizona->dev, "Retrying high impedance\n");
+		info->num_hpdet_res = 0;
+		info->hpdet_retried = true;
+		arizona_start_hpdet_acc_id(info);
+		pm_runtime_put(info->dev);
+		return -EAGAIN;
+	}
 
-		/* Make sure everything is reset back to the real polarity */
-		regmap_update_bits(arizona->regmap,
-				   ARIZONA_ACCESSORY_DETECT_MODE_1,
-				   ARIZONA_ACCDET_SRC,
-				   info->micd_modes[0].src);
+	/*
+	 * If we measure the mic as high impedance
+	 */
+	if (!id_gpio || info->hpdet_res[1] > 50) {
+		dev_dbg(arizona->dev, "Detected mic\n");
+		*mic = true;
+		info->detecting = true;
+	} else {
+		dev_dbg(arizona->dev, "Detected headphone\n");
 	}
 
+	/* Make sure everything is reset back to the real polarity */
+	regmap_update_bits(arizona->regmap, ARIZONA_ACCESSORY_DETECT_MODE_1,
+			   ARIZONA_ACCDET_SRC, info->micd_modes[0].src);
+
 	return 0;
 }
 
@@ -662,11 +666,6 @@ static irqreturn_t arizona_hpdet_irq(int irq, void *data)
 	if (id_gpio)
 		gpio_set_value_cansleep(id_gpio, 0);
 
-	/* Revert back to MICDET mode */
-	regmap_update_bits(arizona->regmap,
-			   ARIZONA_ACCESSORY_DETECT_MODE_1,
-			   ARIZONA_ACCDET_MODE_MASK, ARIZONA_ACCDET_MODE_MIC);
-
 	/* If we have a mic then reenable MICDET */
 	if (mic || info->mic)
 		arizona_start_mic(info);
@@ -699,8 +698,7 @@ static void arizona_identify_headphone(struct arizona_extcon_info *info)
 
 	info->hpdet_active = true;
 
-	if (info->mic)
-		arizona_stop_mic(info);
+	arizona_stop_mic(info);
 
 	arizona_extcon_hp_clamp(info, true);
 
@@ -724,8 +722,8 @@ static void arizona_identify_headphone(struct arizona_extcon_info *info)
 	return;
 
 err:
-	regmap_update_bits(arizona->regmap, ARIZONA_ACCESSORY_DETECT_MODE_1,
-			   ARIZONA_ACCDET_MODE_MASK, ARIZONA_ACCDET_MODE_MIC);
+	arizona_extcon_hp_clamp(info, false);
+	pm_runtime_put_autosuspend(info->dev);
 
 	/* Just report headphone */
 	ret = extcon_set_state_sync(info->edev, EXTCON_JACK_HEADPHONE, true);
@@ -781,9 +779,6 @@ static void arizona_start_hpdet_acc_id(struct arizona_extcon_info *info)
 	return;
 
 err:
-	regmap_update_bits(arizona->regmap, ARIZONA_ACCESSORY_DETECT_MODE_1,
-			   ARIZONA_ACCDET_MODE_MASK, ARIZONA_ACCDET_MODE_MIC);
-
 	/* Just report headphone */
 	ret = extcon_set_state_sync(info->edev, EXTCON_JACK_HEADPHONE, true);
 	if (ret != 0)
@@ -806,75 +801,58 @@ static void arizona_micd_timeout_work(struct work_struct *work)
 
 	arizona_identify_headphone(info);
 
-	arizona_stop_mic(info);
-
 	mutex_unlock(&info->lock);
 }
 
-static void arizona_micd_detect(struct work_struct *work)
+static int arizona_micd_adc_read(struct arizona_extcon_info *info)
 {
-	struct arizona_extcon_info *info = container_of(work,
-						struct arizona_extcon_info,
-						micd_detect_work.work);
 	struct arizona *arizona = info->arizona;
-	unsigned int val = 0, lvl;
-	int ret, i, key;
-
-	cancel_delayed_work_sync(&info->micd_timeout_work);
+	unsigned int val;
+	int ret;
 
-	mutex_lock(&info->lock);
+	/* Must disable MICD before we read the ADCVAL */
+	regmap_update_bits(arizona->regmap, ARIZONA_MIC_DETECT_1,
+			   ARIZONA_MICD_ENA, 0);
 
-	/* If the cable was removed while measuring ignore the result */
-	ret = extcon_get_state(info->edev, EXTCON_MECHANICAL);
-	if (ret < 0) {
-		dev_err(arizona->dev, "Failed to check cable state: %d\n",
-				ret);
-		mutex_unlock(&info->lock);
-		return;
-	} else if (!ret) {
-		dev_dbg(arizona->dev, "Ignoring MICDET for removed cable\n");
-		mutex_unlock(&info->lock);
-		return;
+	ret = regmap_read(arizona->regmap, ARIZONA_MIC_DETECT_4, &val);
+	if (ret != 0) {
+		dev_err(arizona->dev,
+			"Failed to read MICDET_ADCVAL: %d\n", ret);
+		return ret;
 	}
 
-	if (info->detecting && arizona->pdata.micd_software_compare) {
-		/* Must disable MICD before we read the ADCVAL */
-		regmap_update_bits(arizona->regmap, ARIZONA_MIC_DETECT_1,
-				   ARIZONA_MICD_ENA, 0);
-		ret = regmap_read(arizona->regmap, ARIZONA_MIC_DETECT_4, &val);
-		if (ret != 0) {
-			dev_err(arizona->dev,
-				"Failed to read MICDET_ADCVAL: %d\n",
-				ret);
-			mutex_unlock(&info->lock);
-			return;
-		}
+	dev_dbg(arizona->dev, "MICDET_ADCVAL: %x\n", val);
 
-		dev_dbg(arizona->dev, "MICDET_ADCVAL: %x\n", val);
+	val &= ARIZONA_MICDET_ADCVAL_MASK;
+	if (val < ARRAY_SIZE(arizona_micd_levels))
+		val = arizona_micd_levels[val];
+	else
+		val = INT_MAX;
+
+	if (val <= QUICK_HEADPHONE_MAX_OHM)
+		val = ARIZONA_MICD_STS | ARIZONA_MICD_LVL_0;
+	else if (val <= MICROPHONE_MIN_OHM)
+		val = ARIZONA_MICD_STS | ARIZONA_MICD_LVL_1;
+	else if (val <= MICROPHONE_MAX_OHM)
+		val = ARIZONA_MICD_STS | ARIZONA_MICD_LVL_8;
+	else
+		val = ARIZONA_MICD_LVL_8;
 
-		val &= ARIZONA_MICDET_ADCVAL_MASK;
-		if (val < ARRAY_SIZE(arizona_micd_levels))
-			val = arizona_micd_levels[val];
-		else
-			val = INT_MAX;
-
-		if (val <= QUICK_HEADPHONE_MAX_OHM)
-			val = ARIZONA_MICD_STS | ARIZONA_MICD_LVL_0;
-		else if (val <= MICROPHONE_MIN_OHM)
-			val = ARIZONA_MICD_STS | ARIZONA_MICD_LVL_1;
-		else if (val <= MICROPHONE_MAX_OHM)
-			val = ARIZONA_MICD_STS | ARIZONA_MICD_LVL_8;
-		else
-			val = ARIZONA_MICD_LVL_8;
-	}
+	return val;
+}
+
+static int arizona_micd_read(struct arizona_extcon_info *info)
+{
+	struct arizona *arizona = info->arizona;
+	unsigned int val = 0;
+	int ret, i;
 
 	for (i = 0; i < 10 && !(val & MICD_LVL_0_TO_8); i++) {
 		ret = regmap_read(arizona->regmap, ARIZONA_MIC_DETECT_3, &val);
 		if (ret != 0) {
 			dev_err(arizona->dev,
 				"Failed to read MICDET: %d\n", ret);
-			mutex_unlock(&info->lock);
-			return;
+			return ret;
 		}
 
 		dev_dbg(arizona->dev, "MICDET: %x\n", val);
@@ -882,29 +860,44 @@ static void arizona_micd_detect(struct work_struct *work)
 		if (!(val & ARIZONA_MICD_VALID)) {
 			dev_warn(arizona->dev,
 				 "Microphone detection state invalid\n");
-			mutex_unlock(&info->lock);
-			return;
+			return -EINVAL;
 		}
 	}
 
 	if (i == 10 && !(val & MICD_LVL_0_TO_8)) {
 		dev_err(arizona->dev, "Failed to get valid MICDET value\n");
-		mutex_unlock(&info->lock);
-		return;
+		return -EINVAL;
 	}
 
+	return val;
+}
+
+static int arizona_micdet_reading(void *priv)
+{
+	struct arizona_extcon_info *info = priv;
+	struct arizona *arizona = info->arizona;
+	int ret, val;
+
+	if (info->detecting && arizona->pdata.micd_software_compare)
+		ret = arizona_micd_adc_read(info);
+	else
+		ret = arizona_micd_read(info);
+	if (ret < 0)
+		return ret;
+
+	val = ret;
+
 	/* Due to jack detect this should never happen */
 	if (!(val & ARIZONA_MICD_STS)) {
 		dev_warn(arizona->dev, "Detected open circuit\n");
 		info->mic = false;
-		arizona_stop_mic(info);
 		info->detecting = false;
 		arizona_identify_headphone(info);
-		goto handled;
+		return 0;
 	}
 
 	/* If we got a high impedence we should have a headset, report it. */
-	if (info->detecting && (val & ARIZONA_MICD_LVL_8)) {
+	if (val & ARIZONA_MICD_LVL_8) {
 		info->mic = true;
 		info->detecting = false;
 
@@ -923,7 +916,7 @@ static void arizona_micd_detect(struct work_struct *work)
 				ret);
 		}
 
-		goto handled;
+		return 0;
 	}
 
 	/* If we detected a lower impedence during initial startup
@@ -932,15 +925,13 @@ static void arizona_micd_detect(struct work_struct *work)
 	 * plain headphones.  If both polarities report a low
 	 * impedence then give up and report headphones.
 	 */
-	if (info->detecting && (val & MICD_LVL_1_TO_7)) {
+	if (val & MICD_LVL_1_TO_7) {
 		if (info->jack_flips >= info->micd_num_modes * 10) {
 			dev_dbg(arizona->dev, "Detected HP/line\n");
 
 			info->detecting = false;
 
 			arizona_identify_headphone(info);
-
-			arizona_stop_mic(info);
 		} else {
 			info->micd_mode++;
 			if (info->micd_mode == info->micd_num_modes)
@@ -948,11 +939,43 @@ static void arizona_micd_detect(struct work_struct *work)
 			arizona_extcon_set_mode(info, info->micd_mode);
 
 			info->jack_flips++;
+
+			if (arizona->pdata.micd_software_compare)
+				regmap_update_bits(arizona->regmap,
+						   ARIZONA_MIC_DETECT_1,
+						   ARIZONA_MICD_ENA,
+						   ARIZONA_MICD_ENA);
+
+			queue_delayed_work(system_power_efficient_wq,
+					   &info->micd_timeout_work,
+					   msecs_to_jiffies(arizona->pdata.micd_timeout));
 		}
 
-		goto handled;
+		return 0;
 	}
 
+	/*
+	 * If we're still detecting and we detect a short then we've
+	 * got a headphone.
+	 */
+	dev_dbg(arizona->dev, "Headphone detected\n");
+	info->detecting = false;
+
+	arizona_identify_headphone(info);
+
+	return 0;
+}
+
+static int arizona_button_reading(void *priv)
+{
+	struct arizona_extcon_info *info = priv;
+	struct arizona *arizona = info->arizona;
+	int val, key, lvl, i;
+
+	val = arizona_micd_read(info);
+	if (val < 0)
+		return val;
+
 	/*
 	 * If we're still detecting and we detect a short then we've
 	 * got a headphone.  Otherwise it's a button press.
@@ -968,20 +991,13 @@ static void arizona_micd_detect(struct work_struct *work)
 				input_report_key(info->input,
 						 info->micd_ranges[i].key, 0);
 
-			WARN_ON(!lvl);
-			WARN_ON(ffs(lvl) - 1 >= info->num_micd_ranges);
 			if (lvl && ffs(lvl) - 1 < info->num_micd_ranges) {
 				key = info->micd_ranges[ffs(lvl) - 1].key;
 				input_report_key(info->input, key, 1);
 				input_sync(info->input);
+			} else {
+				dev_err(arizona->dev, "Button out of range\n");
 			}
-
-		} else if (info->detecting) {
-			dev_dbg(arizona->dev, "Headphone detected\n");
-			info->detecting = false;
-			arizona_stop_mic(info);
-
-			arizona_identify_headphone(info);
 		} else {
 			dev_warn(arizona->dev, "Button with no mic: %x\n",
 				 val);
@@ -995,19 +1011,39 @@ static void arizona_micd_detect(struct work_struct *work)
 		arizona_extcon_pulse_micbias(info);
 	}
 
-handled:
-	if (info->detecting) {
-		if (arizona->pdata.micd_software_compare)
-			regmap_update_bits(arizona->regmap,
-					   ARIZONA_MIC_DETECT_1,
-					   ARIZONA_MICD_ENA,
-					   ARIZONA_MICD_ENA);
+	return 0;
+}
 
-		queue_delayed_work(system_power_efficient_wq,
-				   &info->micd_timeout_work,
-				   msecs_to_jiffies(info->micd_timeout));
+static void arizona_micd_detect(struct work_struct *work)
+{
+	struct arizona_extcon_info *info = container_of(work,
+						struct arizona_extcon_info,
+						micd_detect_work.work);
+	struct arizona *arizona = info->arizona;
+	int ret;
+
+	cancel_delayed_work_sync(&info->micd_timeout_work);
+
+	mutex_lock(&info->lock);
+
+	/* If the cable was removed while measuring ignore the result */
+	ret = extcon_get_state(info->edev, EXTCON_MECHANICAL);
+	if (ret < 0) {
+		dev_err(arizona->dev, "Failed to check cable state: %d\n",
+				ret);
+		mutex_unlock(&info->lock);
+		return;
+	} else if (!ret) {
+		dev_dbg(arizona->dev, "Ignoring MICDET for removed cable\n");
+		mutex_unlock(&info->lock);
+		return;
 	}
 
+	if (info->detecting)
+		arizona_micdet_reading(info);
+	else
+		arizona_button_reading(info);
+
 	pm_runtime_mark_last_busy(info->dev);
 	mutex_unlock(&info->lock);
 }
@@ -1125,7 +1161,7 @@ static irqreturn_t arizona_jackdet(int irq, void *data)
 					   msecs_to_jiffies(HPDET_DEBOUNCE));
 
 		if (cancelled_mic) {
-			int micd_timeout = info->micd_timeout;
+			int micd_timeout = arizona->pdata.micd_timeout;
 
 			queue_delayed_work(system_power_efficient_wq,
 					   &info->micd_timeout_work,
@@ -1145,11 +1181,11 @@ static irqreturn_t arizona_jackdet(int irq, void *data)
 			dev_err(arizona->dev, "Mechanical report failed: %d\n",
 				ret);
 
-		if (!arizona->pdata.hpdet_acc_id) {
-			info->detecting = true;
-			info->mic = false;
-			info->jack_flips = 0;
+		info->detecting = true;
+		info->mic = false;
+		info->jack_flips = 0;
 
+		if (!arizona->pdata.hpdet_acc_id) {
 			arizona_start_mic(info);
 		} else {
 			queue_delayed_work(system_power_efficient_wq,
@@ -1202,11 +1238,6 @@ static irqreturn_t arizona_jackdet(int irq, void *data)
 				   ARIZONA_MICD_CLAMP_DB | ARIZONA_JD1_DB);
 	}
 
-	if (arizona->pdata.micd_timeout)
-		info->micd_timeout = arizona->pdata.micd_timeout;
-	else
-		info->micd_timeout = DEFAULT_MICD_TIMEOUT;
-
 out:
 	/* Clear trig_sts to make sure DCVDD is not forced up */
 	regmap_write(arizona->regmap, ARIZONA_AOD_WKUP_AND_TRIG,
@@ -1435,6 +1466,9 @@ static int arizona_extcon_probe(struct platform_device *pdev)
 	info->input->name = "Headset";
 	info->input->phys = "arizona/extcon";
 
+	if (!pdata->micd_timeout)
+		pdata->micd_timeout = DEFAULT_MICD_TIMEOUT;
+
 	if (pdata->num_micd_configs) {
 		info->micd_modes = pdata->micd_configs;
 		info->micd_num_modes = pdata->num_micd_configs;

drivers/extcon/extcon-sm5502.c

@@ -249,7 +249,7 @@ static int sm5502_muic_set_path(struct sm5502_muic_info *info,
 		dev_err(info->dev, "Unknown DM_CON/DP_CON switch type (%d)\n",
 				con_sw);
 		return -EINVAL;
-	};
+	}
 
 	switch (vbus_sw) {
 	case VBUSIN_SWITCH_OPEN:
@@ -268,7 +268,7 @@ static int sm5502_muic_set_path(struct sm5502_muic_info *info,
 	default:
 		dev_err(info->dev, "Unknown VBUS switch type (%d)\n", vbus_sw);
 		return -EINVAL;
-	};
+	}
 
 	return 0;
 }
@@ -357,13 +357,13 @@ static unsigned int sm5502_muic_get_cable_type(struct sm5502_muic_info *info)
 				"cannot identify the cable type: adc(0x%x)\n",
 				adc);
 			return -EINVAL;
-		};
+		}
 		break;
 	default:
 		dev_err(info->dev,
 			"failed to identify the cable type: adc(0x%x)\n", adc);
 		return -EINVAL;
-	};
+	}
 
 	return cable_type;
 }
@@ -405,7 +405,7 @@ static int sm5502_muic_cable_handler(struct sm5502_muic_info *info,
 		dev_dbg(info->dev,
 			"cannot handle this cable_type (0x%x)\n", cable_type);
 		return 0;
-	};
+	}
 
 	/* Change internal hardware path(DM_CON/DP_CON, VBUSIN) */
 	ret = sm5502_muic_set_path(info, con_sw, vbus_sw, attached);

include/linux/extcon.h

@@ -170,7 +170,7 @@ struct extcon_dev;
  * Following APIs get the connected state of each external connector.
  * The 'id' argument indicates the defined external connector.
  */
-extern int extcon_get_state(struct extcon_dev *edev, unsigned int id);
+int extcon_get_state(struct extcon_dev *edev, unsigned int id);
 
 /*
  * Following APIs get the property of each external connector.
@@ -181,10 +181,10 @@ extern int extcon_get_state(struct extcon_dev *edev, unsigned int id);
  * for each external connector. They are used to get the capability of the
  * property of each external connector based on the id and property.
  */
-extern int extcon_get_property(struct extcon_dev *edev, unsigned int id,
+int extcon_get_property(struct extcon_dev *edev, unsigned int id,
 				unsigned int prop,
 				union extcon_property_value *prop_val);
-extern int extcon_get_property_capability(struct extcon_dev *edev,
+int extcon_get_property_capability(struct extcon_dev *edev,
 				unsigned int id, unsigned int prop);
 
 /*
@@ -196,38 +196,38 @@ extern int extcon_get_property_capability(struct extcon_dev *edev,
  * extcon_register_notifier_all(*edev, *nb) : Register a notifier block
  *			for all supported external connectors of the extcon.
  */
-extern int extcon_register_notifier(struct extcon_dev *edev, unsigned int id,
+int extcon_register_notifier(struct extcon_dev *edev, unsigned int id,
 				struct notifier_block *nb);
-extern int extcon_unregister_notifier(struct extcon_dev *edev, unsigned int id,
+int extcon_unregister_notifier(struct extcon_dev *edev, unsigned int id,
 				struct notifier_block *nb);
-extern int devm_extcon_register_notifier(struct device *dev,
+int devm_extcon_register_notifier(struct device *dev,
 				struct extcon_dev *edev, unsigned int id,
 				struct notifier_block *nb);
-extern void devm_extcon_unregister_notifier(struct device *dev,
+void devm_extcon_unregister_notifier(struct device *dev,
 				struct extcon_dev *edev, unsigned int id,
 				struct notifier_block *nb);
 
-extern int extcon_register_notifier_all(struct extcon_dev *edev,
+int extcon_register_notifier_all(struct extcon_dev *edev,
 				struct notifier_block *nb);
-extern int extcon_unregister_notifier_all(struct extcon_dev *edev,
+int extcon_unregister_notifier_all(struct extcon_dev *edev,
 				struct notifier_block *nb);
-extern int devm_extcon_register_notifier_all(struct device *dev,
+int devm_extcon_register_notifier_all(struct device *dev,
 				struct extcon_dev *edev,
 				struct notifier_block *nb);
-extern void devm_extcon_unregister_notifier_all(struct device *dev,
+void devm_extcon_unregister_notifier_all(struct device *dev,
 				struct extcon_dev *edev,
 				struct notifier_block *nb);
 
 /*
  * Following APIs get the extcon_dev from devicetree or by through extcon name.
  */
-extern struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name);
-extern struct extcon_dev *extcon_find_edev_by_node(struct device_node *node);
-extern struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev,
+struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name);
+struct extcon_dev *extcon_find_edev_by_node(struct device_node *node);
+struct extcon_dev *extcon_get_edev_by_phandle(struct device *dev,
 						     int index);
 
 /* Following API get the name of extcon device. */
-extern const char *extcon_get_edev_name(struct extcon_dev *edev);
+const char *extcon_get_edev_name(struct extcon_dev *edev);
 
 #else /* CONFIG_EXTCON */
 static inline int extcon_get_state(struct extcon_dev *edev, unsigned int id)