ab8500-charger: AB workaround for invalid charger

AB8500 refuses to start charging when some types of non standard
chargers are connected. This change force the AB to start charging.

Signed-off-by: Henrik Sölver <henrik.solver@stericsson.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Yvan FILLION <yvan.fillion@stericsson.com>
Reviewed-by: Jonas ABERG <jonas.aberg@stericsson.com>
Tested-by: Yvan FILLION <yvan.fillion@stericsson.com>

diff --git a/drivers/power/ab8500_charger.c b/drivers/power/ab8500_charger.c
index 43ec82ba427589236a46beb3f379eee514fd3b6c..4c66172aaa64067737284e0912c2cde4de42c892 100644 (file)
--- a/drivers/power/ab8500_charger.c
+++ b/drivers/power/ab8500_charger.c
@@ -207,6 +207,7 @@ struct ab8500_charger_usb_state {
  * @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"
+ * @invalid_charger_detect_state State when forcing AB to use invalid charger
  * @parent:            Pointer to the struct ab8500
  * @gpadc:             Pointer to the struct gpadc
  * @bm:                Platform specific battery management information
@@ -251,6 +252,7 @@ struct ab8500_charger {
        bool usb_device_is_unrecognised;
        bool autopower;
        bool autopower_cfg;
+       int invalid_charger_detect_state;
        struct ab8500 *parent;
        struct ab8500_gpadc *gpadc;
        struct abx500_bm_data *bm;
@@ -659,7 +661,6 @@ static int ab8500_charger_max_usb_curr(struct ab8500_charger *di,
                        break;
                }
        case USB_STAT_HM_IDGND:
-       case USB_STAT_NOT_VALID_LINK:
                dev_err(di->dev, "USB Type - Charging not allowed\n");
                di->max_usb_in_curr = USB_CH_IP_CUR_LVL_0P05;
                ret = -ENXIO;
@@ -688,6 +689,9 @@ static int ab8500_charger_max_usb_curr(struct ab8500_charger *di,
                di->max_usb_in_curr = USB_CH_IP_CUR_LVL_0P5;
                dev_dbg(di->dev, "USB Type - 0x%02x MaxCurr: %d", link_status,
                                di->max_usb_in_curr);
+       case USB_STAT_NOT_VALID_LINK:
+               dev_err(di->dev, "USB Type invalid - try charging anyway\n");
+               di->max_usb_in_curr = USB_CH_IP_CUR_LVL_0P5;
                break;
 
        default:
@@ -1957,7 +1961,9 @@ static void ab8500_charger_usb_link_attach_work(struct work_struct *work)
  */
 static void ab8500_charger_usb_link_status_work(struct work_struct *work)
 {
+       int detected_chargers;
        int ret;
+       u8 val;
 
        struct ab8500_charger *di = container_of(work,
                struct ab8500_charger, usb_link_status_work);
@@ -1967,11 +1973,55 @@ static void ab8500_charger_usb_link_status_work(struct work_struct *work)
         * synchronously, we have the check if  is
         * connected by reading the status register
         */
-       ret = ab8500_charger_detect_chargers(di);
-       if (ret < 0)
+       detected_chargers = ab8500_charger_detect_chargers(di);
+       if (detected_chargers < 0)
                return;
 
-       if (!(ret & USB_PW_CONN)) {
+       /*
+        * Some chargers that breaks the USB spec is
+        * identified as invalid by AB8500 and it refuse
+        * to start the charging process. but by jumping
+        * thru a few hoops it can be forced to start.
+        */
+       ret = abx500_get_register_interruptible(di->dev, AB8500_USB,
+                       AB8500_USB_LINE_STAT_REG, &val);
+       if (ret >= 0)
+               dev_dbg(di->dev, "UsbLineStatus register = 0x%02x\n", val);
+       else
+               dev_dbg(di->dev, "Error reading USB link status\n");
+
+       if (detected_chargers & USB_PW_CONN) {
+               if (((val & AB8500_USB_LINK_STATUS) >> 3) == USB_STAT_NOT_VALID_LINK &&
+                               di->invalid_charger_detect_state == 0) {
+                       dev_dbg(di->dev, "Invalid charger detected, state= 0\n");
+                       /*Enable charger*/
+                       abx500_mask_and_set_register_interruptible(di->dev,
+                                       AB8500_CHARGER, AB8500_USBCH_CTRL1_REG, 0x01, 0x01);
+                       /*Enable charger detection*/
+                       abx500_mask_and_set_register_interruptible(di->dev, AB8500_USB,
+                                       AB8500_MCH_IPT_CURLVL_REG, 0x01, 0x01);
+                       di->invalid_charger_detect_state = 1;
+                       /*exit and wait for new link status interrupt.*/
+                       return;
+
+               }
+               if (di->invalid_charger_detect_state == 1) {
+                       dev_dbg(di->dev, "Invalid charger detected, state= 1\n");
+                       /*Stop charger detection*/
+                       abx500_mask_and_set_register_interruptible(di->dev, AB8500_USB,
+                                       AB8500_MCH_IPT_CURLVL_REG, 0x01, 0x00);
+                       /*Check link status*/
+                       ret = abx500_get_register_interruptible(di->dev, AB8500_USB,
+                                       AB8500_USB_LINE_STAT_REG, &val);
+                       dev_dbg(di->dev, "USB link status= 0x%02x\n",
+                                       (val & AB8500_USB_LINK_STATUS) >> 3);
+                       di->invalid_charger_detect_state = 2;
+               }
+       } else {
+               di->invalid_charger_detect_state = 0;
+       }
+
+       if (!(detected_chargers & USB_PW_CONN)) {
                di->vbus_detected = 0;
                ab8500_charger_set_usb_connected(di, false);
                ab8500_power_supply_changed(di, &di->usb_chg.psy);
@@ -2884,6 +2934,7 @@ static int ab8500_charger_probe(struct platform_device *pdev)
        spin_lock_init(&di->usb_state.usb_lock);
 
        di->autopower = false;
+       di->invalid_charger_detect_state = 0;
 
        /* AC supply */
        /* power_supply base class */