regulator: twl4030: add support for external voltage get/set

This is needed for SMPS regulators, which use the OMAP voltage
processor for voltage get/set functions instead of the normal I2C
channel. For this purpose, regulator_init_data->driver_data contents
are expanded, it is now a struct which contains function pointers
for the set/get voltage operations, a data pointer for these, and
the previously used features bitmask.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Acked-by: Samuel Ortiz <sameo@linux.intel.com> [for the MFD part]
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/drivers/mfd/twl-core.c b/drivers/mfd/twl-core.c
index e04e04d..fae5f76 100644
--- a/drivers/mfd/twl-core.c
+++ b/drivers/mfd/twl-core.c
@@ -619,6 +619,8 @@
 		unsigned num_consumers, unsigned long features)
 {
 	unsigned sub_chip_id;
+	struct twl_regulator_driver_data drv_data;
+
 	/* regulator framework demands init_data ... */
 	if (!pdata)
 		return NULL;
@@ -628,7 +630,19 @@
 		pdata->num_consumer_supplies = num_consumers;
 	}
 
-	pdata->driver_data = (void *)features;
+	if (pdata->driver_data) {
+		/* If we have existing drv_data, just add the flags */
+		struct twl_regulator_driver_data *tmp;
+		tmp = pdata->driver_data;
+		tmp->features |= features;
+	} else {
+		/* add new driver data struct, used only during init */
+		drv_data.features = features;
+		drv_data.set_voltage = NULL;
+		drv_data.get_voltage = NULL;
+		drv_data.data = NULL;
+		pdata->driver_data = &drv_data;
+	}
 
 	/* NOTE:  we currently ignore regulator IRQs, e.g. for short circuits */
 	sub_chip_id = twl_map[TWL_MODULE_PM_MASTER].sid;