twl4030_charger: Allow charger to control the regulator that feeds it

The charger needs usb3v1 to be running, so add a new consumer to
keep it running.

This allows the charger to draw current even when the USB driver has
powered down.

Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Tero Kristo <t-kristo@ti.com>
Acked-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
diff --git a/drivers/power/twl4030_charger.c b/drivers/power/twl4030_charger.c
index 0511610..bbda083 100644
--- a/drivers/power/twl4030_charger.c
+++ b/drivers/power/twl4030_charger.c
@@ -21,6 +21,7 @@
 #include <linux/power_supply.h>
 #include <linux/notifier.h>
 #include <linux/usb/otg.h>
+#include <linux/regulator/machine.h>
 
 #define TWL4030_BCIMSTATEC	0x02
 #define TWL4030_BCIICHG		0x08
@@ -86,6 +87,8 @@
 	struct work_struct	work;
 	int			irq_chg;
 	int			irq_bci;
+	struct regulator	*usb_reg;
+	int			usb_enabled;
 
 	unsigned long		event;
 };
@@ -183,6 +186,12 @@
 			return -EACCES;
 		}
 
+		/* Need to keep regulator on */
+		if (!bci->usb_enabled) {
+			regulator_enable(bci->usb_reg);
+			bci->usb_enabled = 1;
+		}
+
 		/* forcing the field BCIAUTOUSB (BOOT_BCI[1]) to 1 */
 		ret = twl4030_clear_set_boot_bci(0, TWL4030_BCIAUTOUSB);
 		if (ret < 0)
@@ -193,6 +202,10 @@
 			TWL4030_USBFASTMCHG, TWL4030_BCIMFSTS4);
 	} else {
 		ret = twl4030_clear_set_boot_bci(TWL4030_BCIAUTOUSB, 0);
+		if (bci->usb_enabled) {
+			regulator_disable(bci->usb_reg);
+			bci->usb_enabled = 0;
+		}
 	}
 
 	return ret;
@@ -511,6 +524,8 @@
 	bci->usb.num_properties = ARRAY_SIZE(twl4030_charger_props);
 	bci->usb.get_property = twl4030_bci_get_property;
 
+	bci->usb_reg = regulator_get(bci->dev, "bci3v1");
+
 	ret = power_supply_register(&pdev->dev, &bci->usb);
 	if (ret) {
 		dev_err(&pdev->dev, "failed to register usb: %d\n", ret);