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

From: Chanwoo Choi
Date: Thu Aug 04 2016 - 20:49:33 EST


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