ab8500-bm: Charge only mode fixes for the ab9540

Fix for charging not getting enabled in charge only mode by
external charger.

Signed-off-by: Lee Jones <lee.jones@linaro.org>

1 files changed, 42 insertions, 0 deletions

diff --git a/drivers/power/ab8500_charger.c b/drivers/power/ab8500_charger.c
index 3eb23cf9ff47..f1d712308b02 100644
--- a/drivers/power/ab8500_charger.c
+++ b/drivers/power/ab8500_charger.c
@@ -15,6 +15,7 @@
 #include <linux/device.h>
 #include <linux/interrupt.h>
 #include <linux/delay.h>
+#include <linux/notifier.h>
 #include <linux/slab.h>
 #include <linux/platform_device.h>
 #include <linux/power_supply.h>
@@ -97,6 +98,10 @@
 #define AB8500_SW_CONTROL_FALLBACK      0x03
 /* Wait for enumeration before charing in us */
 #define WAIT_ACA_RID_ENUMERATION        (5 * 1000)
+/*External charger control*/
+#define AB8500_SYS_CHARGER_CONTROL_REG          0x52
+#define EXTERNAL_CHARGER_DISABLE_REG_VAL        0x03
+#define EXTERNAL_CHARGER_ENABLE_REG_VAL         0x07
 
 /* UsbLineStatus register - usb types */
 enum ab8500_charger_link_status {
@@ -1678,6 +1683,29 @@ static int ab8500_charger_usb_en(struct ux500_charger *charger,
         return ret;
 }
 
+static int ab8500_external_charger_prepare(struct notifier_block *charger_nb,
+                                unsigned long event, void *data)
+{
+        int ret;
+        struct device *dev = data;
+        /*Toggle External charger control pin*/
+        ret = abx500_set_register_interruptible(dev, AB8500_SYS_CTRL1_BLOCK,
+                                  AB8500_SYS_CHARGER_CONTROL_REG,
+                                  EXTERNAL_CHARGER_DISABLE_REG_VAL);
+        if (ret < 0) {
+                dev_err(dev, "write reg failed %d\n", ret);
+                goto out;
+        }
+        ret = abx500_set_register_interruptible(dev, AB8500_SYS_CTRL1_BLOCK,
+                                  AB8500_SYS_CHARGER_CONTROL_REG,
+                                  EXTERNAL_CHARGER_ENABLE_REG_VAL);
+        if (ret < 0)
+                dev_err(dev, "Write reg failed %d\n", ret);
+
+out:
+        return ret;
+}
+
 /**
  * ab8500_charger_usb_check_enable() - enable usb charging
  * @charger:    pointer to the ux500_charger structure
@@ -3221,6 +3249,10 @@ static int ab8500_charger_suspend(struct platform_device *pdev,
 #define ab8500_charger_resume       NULL
 #endif
 
+static struct notifier_block charger_nb = {
+        .notifier_call = ab8500_external_charger_prepare,
+};
+
 static int ab8500_charger_remove(struct platform_device *pdev)
 {
         struct ab8500_charger *di = platform_get_drvdata(pdev);
@@ -3250,6 +3282,11 @@ static int ab8500_charger_remove(struct platform_device *pdev)
         /* Delete the work queue */
         destroy_workqueue(di->charger_wq);
 
+        /* Unregister external charger enable notifier */
+        if (!di->ac_chg.enabled)
+                blocking_notifier_chain_unregister(
+                        &charger_notifier_list, &charger_nb);
+
         flush_scheduled_work();
         if (di->usb_chg.enabled)
                 power_supply_unregister(&di->usb_chg.psy);
@@ -3331,6 +3368,11 @@ static int ab8500_charger_probe(struct platform_device *pdev)
         di->ac_chg.enabled = di->bm->ac_enabled;
         di->ac_chg.external = false;
 
+        /*notifier for external charger enabling*/
+        if (!di->ac_chg.enabled)
+                blocking_notifier_chain_register(
+                        &charger_notifier_list, &charger_nb);
+
         /* USB supply */
         /* power_supply base class */
         di->usb_chg.psy.name = "ab8500_usb";