ab8500_charger: Adds support for legacy USB chargers

A Legacy USB charger should be handled directly by the charger
driver.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Marcus Cooper <marcus.xm.cooper@stericsson.com>
Reviewed-by: Karl KOMIEROWSKI <karl.komierowski@stericsson.com>
Reviewed-by: Jonas ABERG <jonas.aberg@stericsson.com>
Signed-off-by: Anton Vorontsov <anton@enomsg.org>

1 files changed, 63 insertions, 16 deletions

diff --git a/drivers/power/ab8500_charger.c b/drivers/power/ab8500_charger.c
index 6ba7efff81e8..d5a8bdadb49a 100644
--- a/drivers/power/ab8500_charger.c
+++ b/drivers/power/ab8500_charger.c
@@ -88,6 +88,9 @@
 /* Step up/down delay in us */
 #define STEP_UDELAY                     1000
 
+/* Wait for enumeration before charging in ms */
+#define WAIT_FOR_USB_ENUMERATION        5 * 1000
+
 #define CHARGER_STATUS_POLL 10 /* in ms */
 
 /* UsbLineStatus register - usb types */
@@ -201,6 +204,7 @@ struct ab8500_charger_usb_state {
  *                      charger is enabled
  * @vbat                Battery voltage
  * @old_vbat            Previously measured battery voltage
+ * @usb_device_is_unrecognised  USB device is unrecognised by the hardware
  * @autopower           Indicate if we should have automatic pwron after pwrloss
  * @autopower_cfg       platform specific power config support for "pwron after pwrloss"
  * @parent:             Pointer to the struct ab8500
@@ -219,6 +223,7 @@ struct ab8500_charger_usb_state {
  * @check_usbchgnotok_work:     Work for checking USB charger not ok status
  * @kick_wd_work:               Work for kicking the charger watchdog in case
  *                              of ABB rev 1.* due to the watchog logic bug
+ * @attach_work:                Work for checking the usb enumeration
  * @ac_charger_attached_work:   Work for checking if AC charger is still
  *                              connected
  * @usb_charger_attached_work:  Work for checking if USB charger is still
@@ -243,6 +248,7 @@ struct ab8500_charger {
         bool vddadc_en_usb;
         int vbat;
         int old_vbat;
+        bool usb_device_is_unrecognised;
         bool autopower;
         bool autopower_cfg;
         struct ab8500 *parent;
@@ -260,6 +266,7 @@ struct ab8500_charger {
         struct delayed_work check_hw_failure_work;
         struct delayed_work check_usbchgnotok_work;
         struct delayed_work kick_wd_work;
+        struct delayed_work attach_work;
         struct delayed_work ac_charger_attached_work;
         struct delayed_work usb_charger_attached_work;
         struct work_struct ac_work;
@@ -597,6 +604,8 @@ static int ab8500_charger_max_usb_curr(struct ab8500_charger *di,
 {
         int ret = 0;
 
+        di->usb_device_is_unrecognised = false;
+
         switch (link_status) {
         case USB_STAT_STD_HOST_NC:
         case USB_STAT_STD_HOST_C_NS:
@@ -642,9 +651,15 @@ static int ab8500_charger_max_usb_curr(struct ab8500_charger *di,
                 dev_dbg(di->dev, "USB Type - 0x%02x MaxCurr: %d", link_status,
                                 di->max_usb_in_curr);
                 break;
+        case USB_STAT_NOT_CONFIGURED:
+                if (di->vbus_detected) {
+                        di->usb_device_is_unrecognised = true;
+                        dev_dbg(di->dev, "USB Type - Legacy charger.\n");
+                        di->max_usb_in_curr = USB_CH_IP_CUR_LVL_1P5;
+                        break;
+                }
         case USB_STAT_HM_IDGND:
         case USB_STAT_NOT_VALID_LINK:
-        case USB_STAT_NOT_CONFIGURED:
                 dev_err(di->dev, "USB Type - Charging not allowed\n");
                 di->max_usb_in_curr = USB_CH_IP_CUR_LVL_0P05;
                 ret = -ENXIO;
@@ -1912,6 +1927,29 @@ static void ab8500_charger_detect_usb_type_work(struct work_struct *work)
 }
 
 /**
+ * ab8500_charger_usb_link_attach_work() - delayd work to detect USB type
+ * @work:       pointer to the work_struct structure
+ *
+ * Detect the type of USB plugged
+ */
+static void ab8500_charger_usb_link_attach_work(struct work_struct *work)
+{
+        struct ab8500_charger *di =
+                container_of(work, struct ab8500_charger, attach_work.work);
+        int ret;
+
+        /* Update maximum input current if USB enumeration is not detected */
+        if (!di->usb.charger_online) {
+                ret = ab8500_charger_set_vbus_in_curr(di, di->max_usb_in_curr);
+                if (ret)
+                        return;
+        }
+
+        ab8500_charger_set_usb_connected(di, true);
+        ab8500_power_supply_changed(di, &di->usb_chg.psy);
+}
+
+/**
  * ab8500_charger_usb_link_status_work() - work to detect USB type
  * @work:       pointer to the work_struct structure
  *
@@ -1937,23 +1975,29 @@ static void ab8500_charger_usb_link_status_work(struct work_struct *work)
                 di->vbus_detected = 0;
                 ab8500_charger_set_usb_connected(di, false);
                 ab8500_power_supply_changed(di, &di->usb_chg.psy);
-        } else {
-                di->vbus_detected = 1;
-                ret = ab8500_charger_read_usb_type(di);
-                if (!ret) {
-                        /* Update maximum input current */
-                        ret = ab8500_charger_set_vbus_in_curr(di,
-                                        di->max_usb_in_curr);
-                        if (ret)
-                                return;
+                return;
+        }
 
-                        ab8500_charger_set_usb_connected(di, true);
-                        ab8500_power_supply_changed(di, &di->usb_chg.psy);
-                } else if (ret == -ENXIO) {
-                        /* No valid charger type detected */
-                        ab8500_charger_set_usb_connected(di, false);
-                        ab8500_power_supply_changed(di, &di->usb_chg.psy);
+        di->vbus_detected = 1;
+        ret = ab8500_charger_read_usb_type(di);
+        if (!ret) {
+                if (di->usb_device_is_unrecognised) {
+                        dev_dbg(di->dev,
+                                "Potential Legacy Charger device. "
+                                "Delay work for %d msec for USB enum "
+                                "to finish",
+                                WAIT_FOR_USB_ENUMERATION);
+                        queue_delayed_work(di->charger_wq,
+                                           &di->attach_work,
+                                           msecs_to_jiffies(WAIT_FOR_USB_ENUMERATION));
+                } else {
+                        queue_delayed_work(di->charger_wq,
+                                           &di->attach_work, 0);
                 }
+        } else if (ret == -ENXIO) {
+                /* No valid charger type detected */
+                ab8500_charger_set_usb_connected(di, false);
+                ab8500_power_supply_changed(di, &di->usb_chg.psy);
         }
 }
 
@@ -2911,6 +2955,9 @@ static int ab8500_charger_probe(struct platform_device *pdev)
         INIT_DEFERRABLE_WORK(&di->check_vbat_work,
                 ab8500_charger_check_vbat_work);
 
+        INIT_DELAYED_WORK(&di->attach_work,
+                ab8500_charger_usb_link_attach_work);
+
         /* Init work for charger detection */
         INIT_WORK(&di->usb_link_status_work,
                 ab8500_charger_usb_link_status_work);