pinctrl: renesas: Add support for 1.8V/2.5V I/O voltage levels

Currently, the Renesas pin control driver supports pins that can switch
their I/O voltage levels between either 1.8V and 3.3V, or between 2.5V
and 3.3V.  However, some SoCs have pins that can switch between 1.8V and
2.5V.

Add support for this by replacing the separate SH_PFC_PIN_CFG_IO_VOLTAGE
capability and voltage level flags by a 2-bit field, to cover three
possible I/O voltage switching options.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/0c04925457bf3f7e78e7e3851528d9a4c29246da.1678271030.git.geert+renesas@glider.be

drivers/pinctrl/renesas/core.c

@@ -1114,9 +1114,9 @@ static void __init sh_pfc_check_info(const struct sh_pfc_soc_info *info)
 			}
 		}
 
-		if (pin->configs & SH_PFC_PIN_CFG_IO_VOLTAGE) {
+		if (pin->configs & SH_PFC_PIN_CFG_IO_VOLTAGE_MASK) {
 			if (!info->ops || !info->ops->pin_to_pocctrl)
-				sh_pfc_err_once(power, "SH_PFC_PIN_CFG_IO_VOLTAGE flag set but .pin_to_pocctrl() not implemented\n");
+				sh_pfc_err_once(power, "SH_PFC_PIN_CFG_IO_VOLTAGE set but .pin_to_pocctrl() not implemented\n");
 			else if (info->ops->pin_to_pocctrl(pin->pin, &x) < 0)
 				sh_pfc_err("pin %s: SH_PFC_PIN_CFG_IO_VOLTAGE set but invalid pin_to_pocctrl()\n",
 					   pin->name);

drivers/pinctrl/renesas/pinctrl.c

@@ -559,7 +559,7 @@ static bool sh_pfc_pinconf_validate(struct sh_pfc *pfc, unsigned int _pin,
 		return pin->configs & SH_PFC_PIN_CFG_DRIVE_STRENGTH;
 
 	case PIN_CONFIG_POWER_SOURCE:
-		return pin->configs & SH_PFC_PIN_CFG_IO_VOLTAGE;
+		return pin->configs & SH_PFC_PIN_CFG_IO_VOLTAGE_MASK;
 
 	default:
 		return false;
@@ -612,7 +612,7 @@ static int sh_pfc_pinconf_get(struct pinctrl_dev *pctldev, unsigned _pin,
 	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;
+		unsigned int mode, lo, hi;
 		u32 pocctrl, val;
 		int bit;
 
@@ -625,10 +625,11 @@ static int sh_pfc_pinconf_get(struct pinctrl_dev *pctldev, unsigned _pin,
 
 		val = sh_pfc_read(pfc, pocctrl);
 
-		lower_voltage = (pin->configs & SH_PFC_PIN_VOLTAGE_25_33) ?
-			2500 : 1800;
+		mode = pin->configs & SH_PFC_PIN_CFG_IO_VOLTAGE_MASK;
+		lo = mode <= SH_PFC_PIN_CFG_IO_VOLTAGE_18_33 ? 1800 : 2500;
+		hi = mode >= SH_PFC_PIN_CFG_IO_VOLTAGE_18_33 ? 3300 : 2500;
 
-		arg = (val & BIT(bit)) ? 3300 : lower_voltage;
+		arg = (val & BIT(bit)) ? hi : lo;
 		break;
 	}
 
@@ -684,7 +685,7 @@ static int sh_pfc_pinconf_set(struct pinctrl_dev *pctldev, unsigned _pin,
 			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;
+			unsigned int mode, lo, hi;
 			u32 pocctrl, val;
 			int bit;
 
@@ -695,15 +696,16 @@ static int sh_pfc_pinconf_set(struct pinctrl_dev *pctldev, unsigned _pin,
 			if (WARN(bit < 0, "invalid pin %#x", _pin))
 				return bit;
 
-			lower_voltage = (pin->configs & SH_PFC_PIN_VOLTAGE_25_33) ?
-				2500 : 1800;
+			mode = pin->configs & SH_PFC_PIN_CFG_IO_VOLTAGE_MASK;
+			lo = mode <= SH_PFC_PIN_CFG_IO_VOLTAGE_18_33 ? 1800 : 2500;
+			hi = mode >= SH_PFC_PIN_CFG_IO_VOLTAGE_18_33 ? 3300 : 2500;
 
-			if (mV != lower_voltage && mV != 3300)
+			if (mV != lo && mV != hi)
 				return -EINVAL;
 
 			spin_lock_irqsave(&pfc->lock, flags);
 			val = sh_pfc_read(pfc, pocctrl);
-			if (mV == 3300)
+			if (mV == hi)
 				val |= BIT(bit);
 			else
 				val &= ~BIT(bit);

drivers/pinctrl/renesas/sh_pfc.h

@@ -29,16 +29,13 @@ enum {
 #define SH_PFC_PIN_CFG_PULL_DOWN	(1 << 3)
 #define SH_PFC_PIN_CFG_PULL_UP_DOWN	(SH_PFC_PIN_CFG_PULL_UP | \
 					 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_MASK	GENMASK(5, 4)
+#define SH_PFC_PIN_CFG_IO_VOLTAGE_18_25	(1 << 4)
+#define SH_PFC_PIN_CFG_IO_VOLTAGE_18_33	(2 << 4)
+#define SH_PFC_PIN_CFG_IO_VOLTAGE_25_33	(3 << 4)
 
-#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_DRIVE_STRENGTH	(1 << 6)
 
 #define SH_PFC_PIN_CFG_NO_GPIO		(1 << 31)