regulator: Support MAX8998/LP3974 DVS-GPIO

The previous driver did not support BUCK1-DVS3, BUCK1-DVS4, and
BUCK2-DVS2 modes. This patch adds such modes and an option to block
setting buck1/2 voltages out of the preset values.

Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/include/linux/mfd/max8998.h b/include/linux/mfd/max8998.h
index c22b9a4..61daa16 100644
--- a/include/linux/mfd/max8998.h
+++ b/include/linux/mfd/max8998.h
@@ -70,12 +70,20 @@
  * @num_regulators: number of regultors used
  * @irq_base: base IRQ number for max8998, required for IRQs
  * @ono: power onoff IRQ number for max8998
- * @buck1_max_voltage1: BUCK1 maximum alowed voltage register 1
- * @buck1_max_voltage2: BUCK1 maximum alowed voltage register 2
- * @buck2_max_voltage: BUCK2 maximum alowed voltage
+ * @buck_voltage_lock: Do NOT change the values of the following six
+ *   registers set by buck?_voltage?. The voltage of BUCK1/2 cannot
+ *   be other than the preset values.
+ * @buck1_voltage1: BUCK1 DVS mode 1 voltage register
+ * @buck1_voltage2: BUCK1 DVS mode 2 voltage register
+ * @buck1_voltage3: BUCK1 DVS mode 3 voltage register
+ * @buck1_voltage4: BUCK1 DVS mode 4 voltage register
+ * @buck2_voltage1: BUCK2 DVS mode 1 voltage register
+ * @buck2_voltage2: BUCK2 DVS mode 2 voltage register
  * @buck1_set1: BUCK1 gpio pin 1 to set output voltage
  * @buck1_set2: BUCK1 gpio pin 2 to set output voltage
+ * @buck1_default_idx: Default for BUCK1 gpio pin 1, 2
  * @buck2_set3: BUCK2 gpio pin to set output voltage
+ * @buck2_default_idx: Default for BUCK2 gpio pin.
  * @wakeup: Allow to wake up from suspend
  * @rtc_delay: LP3974 RTC chip bug that requires delay after a register
  * write before reading it.
@@ -85,12 +93,18 @@
 	int				num_regulators;
 	int				irq_base;
 	int				ono;
-	int                             buck1_max_voltage1;
-	int                             buck1_max_voltage2;
-	int                             buck2_max_voltage;
+	bool				buck_voltage_lock;
+	int				buck1_voltage1;
+	int				buck1_voltage2;
+	int				buck1_voltage3;
+	int				buck1_voltage4;
+	int				buck2_voltage1;
+	int				buck2_voltage2;
 	int				buck1_set1;
 	int				buck1_set2;
+	int				buck1_default_idx;
 	int				buck2_set3;
+	int				buck2_default_idx;
 	bool				wakeup;
 	bool				rtc_delay;
 };