am33xx: Add a function to query MPU voltage in uV

For the DM TPS65910 driver I'm working on, querying the MPU voltage
should return a value in uV. This value can then be used by the
regulator's standard function set_value to set the MPU voltage.

Signed-off-by: Felix Brack <fb@ltec.ch>
Reviewed-by: Lokesh Vutla <lokeshvutla@ti.com>

arch/arm/include/asm/arch-am33xx/sys_proto.h

@@ -40,6 +40,7 @@ void enable_norboot_pin_mux(void);
 #endif
 void am33xx_spl_board_init(void);
 int am335x_get_efuse_mpu_max_freq(struct ctrl_dev *cdev);
+int am335x_get_mpu_vdd(int sil_rev, int frequency);
 int am335x_get_tps65910_mpu_vdd(int sil_rev, int frequency);
 #endif
 

arch/arm/mach-omap2/am33xx/sys_info.c

@@ -175,6 +175,22 @@ int am335x_get_efuse_mpu_max_freq(struct ctrl_dev *cdev)
 	return MPUPLL_M_720;
 }
 
+int am335x_get_mpu_vdd(int sil_rev, int frequency)
+{
+	int sel_mask = am335x_get_tps65910_mpu_vdd(sil_rev, frequency);
+
+	switch (sel_mask) {
+	case TPS65910_OP_REG_SEL_1_3_2_5:
+		return 1325000;
+	case TPS65910_OP_REG_SEL_1_2_0:
+		return 1200000;
+	case TPS65910_OP_REG_SEL_1_1_0:
+		return 1100000;
+	default:
+		return 1262500;
+	}
+}
+
 int am335x_get_tps65910_mpu_vdd(int sil_rev, int frequency)
 {
 	/* For PG2.0 and later, we have one set of values. */