usb: phy: Add USB charger support

This patch introduces the usb charger support based on usb phy that
makes an enhancement to a power driver. The basic conception of the
usb charger is that, when one usb charger is added or removed by
reporting from the extcon device state change, the usb charger will
report to power user to set the current limitation.

Power user can register a notifiee on the usb phy by issuing
usb_register_notifier() to get notified by charger status changes
or charger current changes.

we can notify what current to be drawn to power user according to
different charger type, and now we have 2 methods to get charger type.
One is get charger type from extcon subsystem, which also means the
charger state changes. Another is we can get the charger type from
USB controller detecting or PMIC detecting, and the charger state
changes should be told by issuing usb_phy_set_charger_state().

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

1 files changed, 49 insertions, 0 deletions

diff --git a/include/linux/usb/phy.h b/include/linux/usb/phy.h
index 299245105610..de881b171ba9 100644
--- a/include/linux/usb/phy.h
+++ b/include/linux/usb/phy.h
@@ -12,6 +12,7 @@
 #include <linux/extcon.h>
 #include <linux/notifier.h>
 #include <linux/usb.h>
+#include <uapi/linux/usb/charger.h>
 
 enum usb_phy_interface {
         USBPHY_INTERFACE_MODE_UNKNOWN,
@@ -72,6 +73,17 @@ struct usb_phy_io_ops {
         int (*write)(struct usb_phy *x, u32 val, u32 reg);
 };
 
+struct usb_charger_current {
+        unsigned int sdp_min;
+        unsigned int sdp_max;
+        unsigned int dcp_min;
+        unsigned int dcp_max;
+        unsigned int cdp_min;
+        unsigned int cdp_max;
+        unsigned int aca_min;
+        unsigned int aca_max;
+};
+
 struct usb_phy {
         struct device           *dev;
         const char              *label;
@@ -91,6 +103,13 @@ struct usb_phy {
         struct extcon_dev       *id_edev;
         struct notifier_block   vbus_nb;
         struct notifier_block   id_nb;
+        struct notifier_block   type_nb;
+
+        /* Support USB charger */
+        enum usb_charger_type   chg_type;
+        enum usb_charger_state  chg_state;
+        struct usb_charger_current      chg_cur;
+        struct work_struct              chg_work;
 
         /* for notification of usb_phy_events */
         struct atomic_notifier_head     notifier;
@@ -129,6 +148,12 @@ struct usb_phy {
                         enum usb_device_speed speed);
         int     (*notify_disconnect)(struct usb_phy *x,
                         enum usb_device_speed speed);
+
+        /*
+         * Charger detection method can be implemented if you need to
+         * manually detect the charger type.
+         */
+        enum usb_charger_type (*charger_detect)(struct usb_phy *x);
 };
 
 /**
@@ -219,6 +244,12 @@ extern void devm_usb_put_phy(struct device *dev, struct usb_phy *x);
 extern int usb_bind_phy(const char *dev_name, u8 index,
                                 const char *phy_dev_name);
 extern void usb_phy_set_event(struct usb_phy *x, unsigned long event);
+extern void usb_phy_set_charger_current(struct usb_phy *usb_phy,
+                                        unsigned int mA);
+extern void usb_phy_get_charger_current(struct usb_phy *usb_phy,
+                                        unsigned int *min, unsigned int *max);
+extern void usb_phy_set_charger_state(struct usb_phy *usb_phy,
+                                      enum usb_charger_state state);
 #else
 static inline struct usb_phy *usb_get_phy(enum usb_phy_type type)
 {
@@ -270,11 +301,29 @@ static inline int usb_bind_phy(const char *dev_name, u8 index,
 static inline void usb_phy_set_event(struct usb_phy *x, unsigned long event)
 {
 }
+
+static inline void usb_phy_set_charger_current(struct usb_phy *usb_phy,
+                                               unsigned int mA)
+{
+}
+
+static inline void usb_phy_get_charger_current(struct usb_phy *usb_phy,
+                                               unsigned int *min,
+                                               unsigned int *max)
+{
+}
+
+static inline void usb_phy_set_charger_state(struct usb_phy *usb_phy,
+                                             enum usb_charger_state state)
+{
+}
 #endif
 
 static inline int
 usb_phy_set_power(struct usb_phy *x, unsigned mA)
 {
+        usb_phy_set_charger_current(x, mA);
+
         if (x && x->set_power)
                 return x->set_power(x, mA);
         return 0;