extcon: Add the support for extcon property according to extcon type

This patch support the extcon property for the external connector
because each external connector might have the property according to
the H/W design and the specific characteristics.

- EXTCON_PROP_USB_[property name]
- EXTCON_PROP_CHG_[property name]
- EXTCON_PROP_JACK_[property name]
- EXTCON_PROP_DISP_[property name]

Add the new extcon APIs to get/set the property value as following:
- int extcon_get_property(struct extcon_dev *edev, unsigned int id,
			unsigned int prop,
			union extcon_property_value *prop_val)
- int extcon_set_property(struct extcon_dev *edev, unsigned int id,
			unsigned int prop,
			union extcon_property_value prop_val)

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Tested-by: Chris Zhong <zyw@rock-chips.com>
Tested-by: Guenter Roeck <groeck@chromium.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>

drivers/extcon/extcon.c

@@ -196,6 +196,11 @@ struct extcon_cable {
 	struct device_attribute attr_state;
 
 	struct attribute *attrs[3]; /* to be fed to attr_g.attrs */
+
+	union extcon_property_value usb_propval[EXTCON_PROP_USB_CNT];
+	union extcon_property_value chg_propval[EXTCON_PROP_CHG_CNT];
+	union extcon_property_value jack_propval[EXTCON_PROP_JACK_CNT];
+	union extcon_property_value disp_propval[EXTCON_PROP_DISP_CNT];
 };
 
 static struct class *extcon_class;
@@ -248,6 +253,27 @@ static int find_cable_index_by_id(struct extcon_dev *edev, const unsigned int id
 	return -EINVAL;
 }
 
+static int get_extcon_type(unsigned int prop)
+{
+	switch (prop) {
+	case EXTCON_PROP_USB_MIN ... EXTCON_PROP_USB_MAX:
+		return EXTCON_TYPE_USB;
+	case EXTCON_PROP_CHG_MIN ... EXTCON_PROP_CHG_MAX:
+		return EXTCON_TYPE_CHG;
+	case EXTCON_PROP_JACK_MIN ... EXTCON_PROP_JACK_MAX:
+		return EXTCON_TYPE_JACK;
+	case EXTCON_PROP_DISP_MIN ... EXTCON_PROP_DISP_MAX:
+		return EXTCON_TYPE_DISP;
+	default:
+		return -EINVAL;
+	}
+}
+
+static bool is_extcon_attached(struct extcon_dev *edev, unsigned int index)
+{
+	return !!(edev->state & BIT(index));
+}
+
 static bool is_extcon_changed(u32 prev, u32 new, int idx, bool *attached)
 {
 	if (((prev >> idx) & 0x1) != ((new >> idx) & 0x1)) {
@@ -258,6 +284,34 @@ static bool is_extcon_changed(u32 prev, u32 new, int idx, bool *attached)
 	return false;
 }
 
+static bool is_extcon_property_supported(unsigned int id, unsigned int prop)
+{
+	int type;
+
+	/* Check whether the property is supported or not. */
+	type = get_extcon_type(prop);
+	if (type < 0)
+		return false;
+
+	/* Check whether a specific extcon id supports the property or not. */
+	return !!(extcon_info[id].type & type);
+}
+
+static void init_property(struct extcon_dev *edev, unsigned int id, int index)
+{
+	unsigned int type = extcon_info[id].type;
+	struct extcon_cable *cable = &edev->cables[index];
+
+	if (EXTCON_TYPE_USB & type)
+		memset(cable->usb_propval, 0, sizeof(cable->usb_propval));
+	if (EXTCON_TYPE_CHG & type)
+		memset(cable->chg_propval, 0, sizeof(cable->chg_propval));
+	if (EXTCON_TYPE_JACK & type)
+		memset(cable->jack_propval, 0, sizeof(cable->jack_propval));
+	if (EXTCON_TYPE_DISP & type)
+		memset(cable->disp_propval, 0, sizeof(cable->disp_propval));
+}
+
 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 			  char *buf)
 {
@@ -421,7 +475,7 @@ int extcon_get_cable_state_(struct extcon_dev *edev, const unsigned int id)
 	if (edev->max_supported && edev->max_supported <= index)
 		return -EINVAL;
 
-	return !!(edev->state & (1 << index));
+	return is_extcon_attached(edev, index);
 }
 EXPORT_SYMBOL_GPL(extcon_get_cable_state_);
 
@@ -449,11 +503,156 @@ int extcon_set_cable_state_(struct extcon_dev *edev, unsigned int id,
 	if (edev->max_supported && edev->max_supported <= index)
 		return -EINVAL;
 
+	/*
+	 * Initialize the value of extcon property before setting
+	 * the detached state for an external connector.
+	 */
+	if (!cable_state)
+		init_property(edev, id, index);
+
 	state = cable_state ? (1 << index) : 0;
 	return extcon_update_state(edev, 1 << index, state);
 }
 EXPORT_SYMBOL_GPL(extcon_set_cable_state_);
 
+/**
+ * extcon_get_property() - Get the property value of a specific cable.
+ * @edev:		the extcon device that has the cable.
+ * @id:			the unique id of each external connector
+ *			in extcon enumeration.
+ * @prop:		the property id among enum extcon_property.
+ * @prop_val:		the pointer which store the value of property.
+ *
+ * When getting the property value of external connector, the external connector
+ * should be attached. If detached state, function just return 0 without
+ * property value. Also, the each property should be included in the list of
+ * supported properties according to the type of external connectors.
+ *
+ * Returns 0 if success or error number if fail
+ */
+int extcon_get_property(struct extcon_dev *edev, unsigned int id,
+				unsigned int prop,
+				union extcon_property_value *prop_val)
+{
+	struct extcon_cable *cable;
+	unsigned long flags;
+	int index, ret = 0;
+
+	*prop_val = (union extcon_property_value)(0);
+
+	if (!edev)
+		return -EINVAL;
+
+	/* Check whether the property is supported or not */
+	if (!is_extcon_property_supported(id, prop))
+		return -EINVAL;
+
+	/* Find the cable index of external connector by using id */
+	index = find_cable_index_by_id(edev, id);
+	if (index < 0)
+		return index;
+
+	spin_lock_irqsave(&edev->lock, flags);
+
+	/*
+	 * Check whether the external connector is attached.
+	 * If external connector is detached, the user can not
+	 * get the property value.
+	 */
+	if (!is_extcon_attached(edev, index)) {
+		spin_unlock_irqrestore(&edev->lock, flags);
+		return 0;
+	}
+
+	cable = &edev->cables[index];
+
+	/* Get the property value according to extcon type */
+	switch (prop) {
+	case EXTCON_PROP_USB_MIN ... EXTCON_PROP_USB_MAX:
+		*prop_val = cable->usb_propval[prop - EXTCON_PROP_USB_MIN];
+		break;
+	case EXTCON_PROP_CHG_MIN ... EXTCON_PROP_CHG_MAX:
+		*prop_val = cable->chg_propval[prop - EXTCON_PROP_CHG_MIN];
+		break;
+	case EXTCON_PROP_JACK_MIN ... EXTCON_PROP_JACK_MAX:
+		*prop_val = cable->jack_propval[prop - EXTCON_PROP_JACK_MIN];
+		break;
+	case EXTCON_PROP_DISP_MIN ... EXTCON_PROP_DISP_MAX:
+		*prop_val = cable->disp_propval[prop - EXTCON_PROP_DISP_MIN];
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	spin_unlock_irqrestore(&edev->lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(extcon_get_property);
+
+/**
+ * extcon_set_property() - Set the property value of a specific cable.
+ * @edev:		the extcon device that has the cable.
+ * @id:			the unique id of each external connector
+ *			in extcon enumeration.
+ * @prop:		the property id among enum extcon_property.
+ * @prop_val:		the pointer including the new value of property.
+ *
+ * The each property should be included in the list of supported properties
+ * according to the type of external connectors.
+ *
+ * Returns 0 if success or error number if fail
+ */
+int extcon_set_property(struct extcon_dev *edev, unsigned int id,
+				unsigned int prop,
+				union extcon_property_value prop_val)
+{
+	struct extcon_cable *cable;
+	unsigned long flags;
+	int index, ret = 0;
+
+	if (!edev)
+		return -EINVAL;
+
+	/* Check whether the property is supported or not */
+	if (!is_extcon_property_supported(id, prop))
+		return -EINVAL;
+
+	/* Find the cable index of external connector by using id */
+	index = find_cable_index_by_id(edev, id);
+	if (index < 0)
+		return index;
+
+	spin_lock_irqsave(&edev->lock, flags);
+
+	cable = &edev->cables[index];
+
+	/* Set the property value according to extcon type */
+	switch (prop) {
+	case EXTCON_PROP_USB_MIN ... EXTCON_PROP_USB_MAX:
+		cable->usb_propval[prop - EXTCON_PROP_USB_MIN] = prop_val;
+		break;
+	case EXTCON_PROP_CHG_MIN ... EXTCON_PROP_CHG_MAX:
+		cable->chg_propval[prop - EXTCON_PROP_CHG_MIN] = prop_val;
+		break;
+	case EXTCON_PROP_JACK_MIN ... EXTCON_PROP_JACK_MAX:
+		cable->jack_propval[prop - EXTCON_PROP_JACK_MIN] = prop_val;
+		break;
+	case EXTCON_PROP_DISP_MIN ... EXTCON_PROP_DISP_MAX:
+		cable->disp_propval[prop - EXTCON_PROP_DISP_MIN] = prop_val;
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	spin_unlock_irqrestore(&edev->lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(extcon_set_property);
+
 /**
  * extcon_get_extcon_dev() - Get the extcon device instance from the name
  * @extcon_name:	The extcon name provided with extcon_dev_register()

include/linux/extcon.h

@@ -77,6 +77,63 @@
 
 #define EXTCON_NUM		63
 
+/*
+ * Define the property of supported external connectors.
+ *
+ * When adding the new extcon property, they *must* have
+ * the type/value/default information. Also, you *have to*
+ * modify the EXTCON_PROP_[type]_START/END definitions
+ * which mean the range of the supported properties
+ * for each extcon type.
+ *
+ * The naming style of property
+ * : EXTCON_PROP_[type]_[property name]
+ *
+ * EXTCON_PROP_USB_[property name]	: USB property
+ * EXTCON_PROP_CHG_[property name]	: Charger property
+ * EXTCON_PROP_JACK_[property name]	: Jack property
+ * EXTCON_PROP_DISP_[property name]	: Display property
+ */
+
+/*
+ * Properties of EXTCON_TYPE_USB.
+ *
+ * - EXTCON_PROP_USB_VBUS
+ * @type:	integer (intval)
+ * @value:	0 (low) or 1 (high)
+ * @default:	0 (low)
+ */
+#define EXTCON_PROP_USB_VBUS		0
+
+#define EXTCON_PROP_USB_MIN		0
+#define EXTCON_PROP_USB_MAX		0
+#define EXTCON_PROP_USB_CNT	(EXTCON_PROP_USB_MAX - EXTCON_PROP_USB_MIN + 1)
+
+/* Properties of EXTCON_TYPE_CHG. */
+#define EXTCON_PROP_CHG_MIN		50
+#define EXTCON_PROP_CHG_MAX		50
+#define EXTCON_PROP_CHG_CNT	(EXTCON_PROP_CHG_MAX - EXTCON_PROP_CHG_MIN + 1)
+
+/* Properties of EXTCON_TYPE_JACK. */
+#define EXTCON_PROP_JACK_MIN		100
+#define EXTCON_PROP_JACK_MAX		100
+#define EXTCON_PROP_JACK_CNT (EXTCON_PROP_JACK_MAX - EXTCON_PROP_JACK_MIN + 1)
+
+/* Properties of EXTCON_TYPE_DISP. */
+#define EXTCON_PROP_DISP_MIN		150
+#define EXTCON_PROP_DISP_MAX		150
+#define EXTCON_PROP_DISP_CNT (EXTCON_PROP_DISP_MAX - EXTCON_PROP_DISP_MIN + 1)
+
+/*
+ * Define the type of property's value.
+ *
+ * Define the property's value as union type. Because each property
+ * would need the different data type to store it.
+ */
+union extcon_property_value {
+	int intval;	/* type : integer (intval) */
+};
+
 struct extcon_cable;
 
 /**
@@ -166,6 +223,17 @@ extern int extcon_get_cable_state_(struct extcon_dev *edev, unsigned int id);
 extern int extcon_set_cable_state_(struct extcon_dev *edev, unsigned int id,
 				   bool cable_state);
 
+/*
+ * get/set_property access the property value of each external connector.
+ * They are used to access the property of each cable based on the property id.
+ */
+extern int extcon_get_property(struct extcon_dev *edev, unsigned int id,
+				unsigned int prop,
+				union extcon_property_value *prop_val);
+extern int extcon_set_property(struct extcon_dev *edev, unsigned int id,
+				unsigned int prop,
+				union extcon_property_value prop_val);
+
 /*
  * Following APIs are to monitor every action of a notifier.
  * Registrar gets notified for every external port of a connection device.
@@ -239,6 +307,19 @@ static inline int extcon_set_cable_state_(struct extcon_dev *edev,
 	return 0;
 }
 
+static inline int extcon_get_property(struct extcon_dev *edev, unsigned int id,
+					unsigned int prop,
+					union extcon_property_value *prop_val)
+{
+	return 0;
+}
+static inline int extcon_set_property(struct extcon_dev *edev, unsigned int id,
+					unsigned int prop,
+					union extcon_property_value prop_val)
+{
+	return 0;
+}
+
 static inline struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name)
 {
 	return NULL;