[PATCH v4 2/6] extcon: Add the support for extcon property according to extcon type

[Chanwoo Choi]

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@xxxxxxxxxxx>
Tested-by: Chris Zhong <zyw@xxxxxxxxxxxxxx>
Tested-by: Guenter Roeck <groeck@xxxxxxxxxxxx>
Reviewed-by: Guenter Roeck <groeck@xxxxxxxxxxxx>
---
 drivers/extcon/extcon.c | 201 +++++++++++++++++++++++++++++++++++++++++++++++-
 include/linux/extcon.h  |  81 +++++++++++++++++++
 2 files changed, 281 insertions(+), 1 deletion(-)

diff --git a/drivers/extcon/extcon.c b/drivers/extcon/extcon.c
index f209a6959fed..37fa4b51c5a1 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()
  */
diff --git a/include/linux/extcon.h b/include/linux/extcon.h
index 46d802892c82..f9d4a44e86d3 100644
--- a/include/linux/extcon.h
+++ b/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;
 
 /**
@@ -167,6 +224,17 @@ 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.
  * Probably this could be used to debug an action of notifier; however,
@@ -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;
-- 
1.9.1