extcon: max77843: Add support for SmartDock accessory

SmartDock uses ADC_RESERVED_ACC_3 (0x10) ADC ID type and provides following
features:
1. USB host with embedded USB hub (2-4 ports) for mice, keyboard, etc,
2. MHL for video output,
3. charging.

Tested with Unitek Y-2165 MHL+OTG Hub Smart Phone Dock.

Signed-off-by: Marek Szyprowski <[e-mail]>
Acked-by: Chanwoo Choi <[e-mail]>
Acked-by: Lee Jones <[e-mail]>
Signed-off-by: Chanwoo Choi <[e-mail]>

drivers/extcon/extcon-max77843.c

···
 	MAX77843_MUIC_ADC_REMOTE_S12_BUTTON,
 	MAX77843_MUIC_ADC_RESERVED_ACC_1,
 	MAX77843_MUIC_ADC_RESERVED_ACC_2,
-	MAX77843_MUIC_ADC_RESERVED_ACC_3,
+	MAX77843_MUIC_ADC_RESERVED_ACC_3, /* SmartDock */
 	MAX77843_MUIC_ADC_RESERVED_ACC_4,
 	MAX77843_MUIC_ADC_RESERVED_ACC_5,
 	MAX77843_MUIC_ADC_AUDIO_DEVICE_TYPE2,
···
 	MAX77843_MUIC_CHG_SPECIAL_BIAS,
 	MAX77843_MUIC_CHG_RESERVED,
 	MAX77843_MUIC_CHG_GND,
+	MAX77843_MUIC_CHG_DOCK,
 };
 
 static const unsigned int max77843_extcon_cable[] = {
···
 	EXTCON_CHG_USB_FAST,
 	EXTCON_CHG_USB_SLOW,
 	EXTCON_DISP_MHL,
+	EXTCON_DOCK,
 	EXTCON_JIG,
 	EXTCON_NONE,
 };
···
 };
 
 static int max77843_muic_set_path(struct max77843_muic_info *info,
-		u8 val, bool attached)
+		u8 val, bool attached, bool nobccomp)
 {
 	struct max77693_dev *max77843 = info->max77843;
 	int ret = 0;
···
 		ctrl1 = val;
 	else
 		ctrl1 = MAX77843_MUIC_CONTROL1_SW_OPEN;
+	if (nobccomp) {
+		/* Disable BC1.2 protocol and force manual switch control */
+		ctrl1 |= MAX77843_MUIC_CONTROL1_NOBCCOMP_MASK;
+	}
 
 	ret = regmap_update_bits(max77843->regmap_muic,
 			MAX77843_MUIC_REG_CONTROL1,
-			MAX77843_MUIC_CONTROL1_COM_SW, ctrl1);
+			MAX77843_MUIC_CONTROL1_COM_SW |
+				MAX77843_MUIC_CONTROL1_NOBCCOMP_MASK,
+			ctrl1);
 	if (ret < 0) {
 		dev_err(info->dev, "Cannot switch MUIC port\n");
 		return ret;
···
 			break;
 		}
 
+		if (adc == MAX77843_MUIC_ADC_RESERVED_ACC_3) { /* SmartDock */
+			if (chg_type == MAX77843_MUIC_CHG_NONE) {
+				*attached = false;
+				cable_type = info->prev_chg_type;
+				info->prev_chg_type = MAX77843_MUIC_CHG_NONE;
+			} else {
+				*attached = true;
+				cable_type = MAX77843_MUIC_CHG_DOCK;
+				info->prev_chg_type = MAX77843_MUIC_CHG_DOCK;
+			}
+			break;
+		}
+
 		if (chg_type == MAX77843_MUIC_CHG_NONE) {
 			*attached = false;
 			cable_type = info->prev_chg_type;
···
 	case MAX77843_MUIC_GND_USB_HOST_VB:
 		ret = max77843_muic_set_path(info,
 					     MAX77843_MUIC_CONTROL1_SW_USB,
-					     attached);
+					     attached, false);
 		if (ret < 0)
 			return ret;
 
···
 	case MAX77843_MUIC_GND_MHL:
 		ret = max77843_muic_set_path(info,
 					     MAX77843_MUIC_CONTROL1_SW_OPEN,
-					     attached);
+					     attached, false);
 		if (ret < 0)
 			return ret;
 
···
 		return -EINVAL;
 	}
 
-	ret = max77843_muic_set_path(info, path, attached);
+	ret = max77843_muic_set_path(info, path, attached, false);
 	if (ret < 0)
 		return ret;
 
 	extcon_set_state_sync(info->edev, EXTCON_JIG, attached);
+
+	return 0;
+}
+
+static int max77843_muic_dock_handler(struct max77843_muic_info *info,
+		bool attached)
+{
+	int ret;
+
+	dev_dbg(info->dev, "external connector is %s (adc: 0x10)\n",
+			attached ? "attached" : "detached");
+
+	ret = max77843_muic_set_path(info, MAX77843_MUIC_CONTROL1_SW_USB,
+				     attached, attached);
+	if (ret < 0)
+		return ret;
+
+	extcon_set_state_sync(info->edev, EXTCON_DISP_MHL, attached);
+	extcon_set_state_sync(info->edev, EXTCON_USB_HOST, attached);
+	extcon_set_state_sync(info->edev, EXTCON_DOCK, attached);
 
 	return 0;
 }
···
 		info->prev_cable_type);
 
 	switch (cable_type) {
+	case MAX77843_MUIC_ADC_RESERVED_ACC_3: /* SmartDock */
+		ret = max77843_muic_dock_handler(info, attached);
+		if (ret < 0)
+			return ret;
+		break;
 	case MAX77843_MUIC_ADC_GROUND:
 		ret = max77843_muic_adc_gnd_handler(info);
 		if (ret < 0)
···
 	case MAX77843_MUIC_ADC_REMOTE_S12_BUTTON:
 	case MAX77843_MUIC_ADC_RESERVED_ACC_1:
 	case MAX77843_MUIC_ADC_RESERVED_ACC_2:
-	case MAX77843_MUIC_ADC_RESERVED_ACC_3:
 	case MAX77843_MUIC_ADC_RESERVED_ACC_4:
 	case MAX77843_MUIC_ADC_RESERVED_ACC_5:
 	case MAX77843_MUIC_ADC_AUDIO_DEVICE_TYPE2:
···
 	case MAX77843_MUIC_CHG_USB:
 		ret = max77843_muic_set_path(info,
 					     MAX77843_MUIC_CONTROL1_SW_USB,
-					     attached);
+					     attached, false);
 		if (ret < 0)
 			return ret;
 
···
 	case MAX77843_MUIC_CHG_DOWNSTREAM:
 		ret = max77843_muic_set_path(info,
 					     MAX77843_MUIC_CONTROL1_SW_OPEN,
-					     attached);
+					     attached, false);
 		if (ret < 0)
 			return ret;
 
···
 	case MAX77843_MUIC_CHG_DEDICATED:
 		ret = max77843_muic_set_path(info,
 					     MAX77843_MUIC_CONTROL1_SW_OPEN,
-					     attached);
+					     attached, false);
 		if (ret < 0)
 			return ret;
 
···
 	case MAX77843_MUIC_CHG_SPECIAL_500MA:
 		ret = max77843_muic_set_path(info,
 					     MAX77843_MUIC_CONTROL1_SW_OPEN,
-					     attached);
+					     attached, false);
 		if (ret < 0)
 			return ret;
 
···
 	case MAX77843_MUIC_CHG_SPECIAL_1A:
 		ret = max77843_muic_set_path(info,
 					     MAX77843_MUIC_CONTROL1_SW_OPEN,
-					     attached);
+					     attached, false);
 		if (ret < 0)
 			return ret;
 
···
 			extcon_set_state_sync(info->edev, EXTCON_CHG_USB_DCP,
 						false);
 		break;
+	case MAX77843_MUIC_CHG_DOCK:
+		extcon_set_state_sync(info->edev, EXTCON_CHG_USB_DCP, attached);
+		break;
 	case MAX77843_MUIC_CHG_NONE:
 		break;
 	default:
···
 			attached ? "attached" : "detached", chg_type);
 
 		max77843_muic_set_path(info, MAX77843_MUIC_CONTROL1_SW_OPEN,
-				       attached);
+				       attached, false);
 		return -EINVAL;
 	}
 
···
 	max77843_muic_set_debounce_time(info, MAX77843_DEBOUNCE_TIME_25MS);
 
 	/* Set initial path for UART */
-	max77843_muic_set_path(info, MAX77843_MUIC_CONTROL1_SW_UART, true);
+	max77843_muic_set_path(info, MAX77843_MUIC_CONTROL1_SW_UART, true,
+			       false);
 
 	/* Check revision number of MUIC device */
 	ret = regmap_read(max77843->regmap_muic, MAX77843_MUIC_REG_ID, &id);

include/linux/mfd/max77843-private.h

···
 /* MAX77843 CONTROL register */
 #define MAX77843_MUIC_CONTROL1_COMP1SW_SHIFT	0
 #define MAX77843_MUIC_CONTROL1_COMP2SW_SHIFT	3
+#define MAX77843_MUIC_CONTROL1_NOBCCOMP_SHIFT	6
 #define MAX77843_MUIC_CONTROL1_IDBEN_SHIFT	7
 #define MAX77843_MUIC_CONTROL2_LOWPWR_SHIFT	0
 #define MAX77843_MUIC_CONTROL2_ADCEN_SHIFT	1
···
 #define MAX77843_MUIC_CONTROL1_COMP1SW_MASK	(0x7 << MAX77843_MUIC_CONTROL1_COMP1SW_SHIFT)
 #define MAX77843_MUIC_CONTROL1_COMP2SW_MASK	(0x7 << MAX77843_MUIC_CONTROL1_COMP2SW_SHIFT)
 #define MAX77843_MUIC_CONTROL1_IDBEN_MASK	BIT(MAX77843_MUIC_CONTROL1_IDBEN_SHIFT)
+#define MAX77843_MUIC_CONTROL1_NOBCCOMP_MASK	BIT(MAX77843_MUIC_CONTROL1_NOBCCOMP_SHIFT)
 #define MAX77843_MUIC_CONTROL2_LOWPWR_MASK	BIT(MAX77843_MUIC_CONTROL2_LOWPWR_SHIFT)
 #define MAX77843_MUIC_CONTROL2_ADCEN_MASK	BIT(MAX77843_MUIC_CONTROL2_ADCEN_SHIFT)
 #define MAX77843_MUIC_CONTROL2_CPEN_MASK	BIT(MAX77843_MUIC_CONTROL2_CPEN_SHIFT)