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>

1 files changed, 200 insertions, 1 deletions

diff --git a/drivers/extcon/extcon.c b/drivers/extcon/extcon.c
index f209a69..37fa4b5 100644
--- a/drivers/extcon/extcon.c
+++ b/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_);
 
@@ -449,12 +503,157 @@ 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()
  */