}
 
        case PIN_CONFIG_POWER_SOURCE: {
+               int idx = sh_pfc_get_pin_index(pfc, _pin);
+               const struct sh_pfc_pin *pin = &pfc->info->pins[idx];
+               unsigned int lower_voltage;
                u32 pocctrl, val;
                int bit;
 
                val = sh_pfc_read(pfc, pocctrl);
                spin_unlock_irqrestore(&pfc->lock, flags);
 
-               arg = (val & BIT(bit)) ? 3300 : 1800;
+               lower_voltage = (pin->configs & SH_PFC_PIN_VOLTAGE_25_33) ?
+                       2500 : 1800;
+
+               arg = (val & BIT(bit)) ? 3300 : lower_voltage;
                break;
        }
 
 
                case PIN_CONFIG_POWER_SOURCE: {
                        unsigned int mV = pinconf_to_config_argument(configs[i]);
+                       int idx = sh_pfc_get_pin_index(pfc, _pin);
+                       const struct sh_pfc_pin *pin = &pfc->info->pins[idx];
+                       unsigned int lower_voltage;
                        u32 pocctrl, val;
                        int bit;
 
                        if (WARN(bit < 0, "invalid pin %#x", _pin))
                                return bit;
 
-                       if (mV != 1800 && mV != 3300)
+                       lower_voltage = (pin->configs & SH_PFC_PIN_VOLTAGE_25_33) ?
+                               2500 : 1800;
+
+                       if (mV != lower_voltage && mV != 3300)
                                return -EINVAL;
 
                        spin_lock_irqsave(&pfc->lock, flags);
 
                                         SH_PFC_PIN_CFG_PULL_DOWN)
 #define SH_PFC_PIN_CFG_IO_VOLTAGE      (1 << 4)
 #define SH_PFC_PIN_CFG_DRIVE_STRENGTH  (1 << 5)
+
+#define SH_PFC_PIN_VOLTAGE_18_33       (0 << 6)
+#define SH_PFC_PIN_VOLTAGE_25_33       (1 << 6)
+
+#define SH_PFC_PIN_CFG_IO_VOLTAGE_18_33        (SH_PFC_PIN_CFG_IO_VOLTAGE | \
+                                        SH_PFC_PIN_VOLTAGE_18_33)
+#define SH_PFC_PIN_CFG_IO_VOLTAGE_25_33        (SH_PFC_PIN_CFG_IO_VOLTAGE | \
+                                        SH_PFC_PIN_VOLTAGE_25_33)
+
 #define SH_PFC_PIN_CFG_NO_GPIO         (1 << 31)
 
 struct sh_pfc_pin {