[PATCH v4 1/5] pinctrl: renesas: rzg2l: Generalize the power source code

[Claudiu Beznea <claudiu.beznea+renesas@tuxon.dev>]

From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

The current functions used to get/set the pin power source check the
OTHER_POC register, which is specific to the RZ/G3L SoC only. To allow the
code to be extended for other power source functionalities (e.g. I3C on
RZ/G3S), generalize the functions used to get/set the pin power source.

For this, introduce the struct rzg2l_register_masks data structure whose
purpose is to store SoC specific register bit masks. The members of this
structure are then used in rzg2l_caps_to_pwr_reg() to retrieve the bitmask
corresponding to a SoC specific power source capability.

The conversion between HW specific power source values and SW specific
power source values is now handled through rzg2l_pwr_reg_val_to_ps() and
rzg2l_ps_to_pwr_reg_val().

Finally, to keep the code generic, the register update in
rzg2l_set_power_source() was changed to a read-modify-write approach to
cover all cases.

Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
---

Changes in v4:
- none

Changes in v3:
- collected tags

Changes in v2:
- none

 drivers/pinctrl/renesas/pinctrl-rzg2l.c | 177 +++++++++++++++---------
 1 file changed, 112 insertions(+), 65 deletions(-)

diff --git a/drivers/pinctrl/renesas/pinctrl-rzg2l.c b/drivers/pinctrl/renesas/pinctrl-rzg2l.c
index be52d47d77ae..6f3760851460 100644
--- a/drivers/pinctrl/renesas/pinctrl-rzg2l.c
+++ b/drivers/pinctrl/renesas/pinctrl-rzg2l.c
@@ -186,6 +186,7 @@
 #define PVDD_2500		2	/* I/O domain voltage 2.5V */
 #define PVDD_1800		1	/* I/O domain voltage <= 1.8V */
 #define PVDD_3300		0	/* I/O domain voltage >= 3.3V */
+#define PVDD_MASK		0x3
 
 #define PWPR_B0WI		BIT(7)	/* Bit Write Disable */
 #define PWPR_PFCWE		BIT(6)	/* PFC Register Write Enable */
@@ -268,6 +269,23 @@ struct rzg2l_register_offsets {
 	u16 other_poc;
 };
 
+/**
+ * struct rzg2l_register_masks - Masks for different RZ/G2L pinctrl functionalities
+ * @other_poc_pvdd1833_oth_awo_poc: PVDD1833_OTH_AWO_POC mask
+ * @other_poc_pvdd1833_oth_iso_poc: PVDD1833_OTH_ISO_POC mask
+ * @other_poc_wdtovf_n_poc: WDTOVF_N_POC mask
+ */
+struct rzg2l_register_masks {
+	union {
+		/* RZ/G3L masks */
+		struct {
+			u8 other_poc_pvdd1833_oth_awo_poc;
+			u8 other_poc_pvdd1833_oth_iso_poc;
+			u8 other_poc_wdtovf_n_poc;
+		};
+	};
+};
+
 /**
  * enum rzg2l_iolh_index - starting indices in IOLH specific arrays
  * @RZG2L_IOLH_IDX_1V8: starting index for 1V8 power source
@@ -288,6 +306,8 @@ enum rzg2l_iolh_index {
 /**
  * struct rzg2l_hwcfg - hardware configuration data structure
  * @regs: hardware specific register offsets
+ * @masks: hardware specific masks for various functionalities available in
+ * the registers described by regs
  * @iolh_groupa_ua: IOLH group A uA specific values
  * @iolh_groupb_ua: IOLH group B uA specific values
  * @iolh_groupc_ua: IOLH group C uA specific values
@@ -301,6 +321,7 @@ enum rzg2l_iolh_index {
  */
 struct rzg2l_hwcfg {
 	const struct rzg2l_register_offsets regs;
+	const struct rzg2l_register_masks masks;
 	u16 iolh_groupa_ua[RZG2L_IOLH_IDX_MAX];
 	u16 iolh_groupb_ua[RZG2L_IOLH_IDX_MAX];
 	u16 iolh_groupc_ua[RZG2L_IOLH_IDX_MAX];
@@ -1047,27 +1068,73 @@ static void rzg2l_rmw_pin_config(struct rzg2l_pinctrl *pctrl, u32 offset,
 }
 
 static int rzg2l_caps_to_pwr_reg(const struct rzg2l_register_offsets *regs,
-				 u32 caps, u8 *mask)
+				 const struct rzg2l_register_masks *masks,
+				 u32 caps, u16 *offset, u8 *mask)
 {
-	if (caps & PIN_CFG_IO_VMC_SD0)
-		return SD_CH(regs->sd_ch, 0);
-	if (caps & PIN_CFG_IO_VMC_SD1)
-		return SD_CH(regs->sd_ch, 1);
-	if (caps & PIN_CFG_IO_VMC_ETH0)
-		return ETH_POC(regs->eth_poc, 0);
-	if (caps & PIN_CFG_IO_VMC_ETH1)
-		return ETH_POC(regs->eth_poc, 1);
-	if (caps & PIN_CFG_IO_VMC_QSPI)
-		return QSPI;
+	*mask = PVDD_MASK;
+
+	if (caps & PIN_CFG_IO_VMC_SD0) {
+		*offset = SD_CH(regs->sd_ch, 0);
+		return 0;
+	}
+	if (caps & PIN_CFG_IO_VMC_SD1) {
+		*offset = SD_CH(regs->sd_ch, 1);
+		return 0;
+	}
+	if (caps & PIN_CFG_IO_VMC_ETH0) {
+		*offset = ETH_POC(regs->eth_poc, 0);
+		return 0;
+	}
+	if (caps & PIN_CFG_IO_VMC_ETH1) {
+		*offset = ETH_POC(regs->eth_poc, 1);
+		return 0;
+	}
+	if (caps & PIN_CFG_IO_VMC_QSPI) {
+		*offset = regs->qspi;
+		return 0;
+	}
 	if (caps & PIN_CFG_OTHER_POC_MASK) {
+		*offset = regs->other_poc;
 		if (caps & PIN_CFG_PVDD1833_OTH_AWO_POC)
-			*mask = BIT(0);
+			*mask = masks->other_poc_pvdd1833_oth_awo_poc;
 		else if (caps & PIN_CFG_PVDD1833_OTH_ISO_POC)
-			*mask = BIT(1);
+			*mask = masks->other_poc_pvdd1833_oth_iso_poc;
 		else
-			*mask = BIT(2);
+			*mask = masks->other_poc_wdtovf_n_poc;
+		return 0;
+	}
 
-		return OTHER_POC;
+	return -EINVAL;
+}
+
+static int rzg2l_pwr_reg_val_to_ps(u8 val, u32 caps)
+{
+	switch (val) {
+	case PVDD_1800:
+		return 1800;
+	case PVDD_2500:
+		return 2500;
+	case PVDD_3300:
+		return 3300;
+	}
+
+	return -EINVAL;
+}
+
+static int rzg2l_ps_to_pwr_reg_val(u8 *val, u32 ps, u32 caps)
+{
+	switch (ps) {
+	case 1800:
+		*val = PVDD_1800;
+		return 0;
+	case 2500:
+		if (!(caps & (PIN_CFG_IO_VMC_ETH0 | PIN_CFG_IO_VMC_ETH1)))
+			return -EINVAL;
+		*val = PVDD_2500;
+		return 0;
+	case 3300:
+		*val = PVDD_3300;
+		return 0;
 	}
 
 	return -EINVAL;
@@ -1077,76 +1144,51 @@ static int rzg2l_get_power_source(struct rzg2l_pinctrl *pctrl, u32 pin, u32 caps
 {
 	const struct rzg2l_hwcfg *hwcfg = pctrl->data->hwcfg;
 	const struct rzg2l_register_offsets *regs = &hwcfg->regs;
-	u8 val, mask;
-	int pwr_reg;
+	const struct rzg2l_register_masks *masks = &hwcfg->masks;
+	u8 mask, val;
+	u16 offset;
+	int ret;
 
 	if (caps & PIN_CFG_SOFT_PS)
 		return pctrl->settings[pin].power_source;
 
-	pwr_reg = rzg2l_caps_to_pwr_reg(regs, caps, &mask);
-	if (pwr_reg < 0)
-		return pwr_reg;
+	ret = rzg2l_caps_to_pwr_reg(regs, masks, caps, &offset, &mask);
+	if (ret)
+		return ret;
 
-	val = readb(pctrl->base + pwr_reg);
-	if (pwr_reg == OTHER_POC)
-		val = field_get(mask, val);
+	val = readb(pctrl->base + offset);
 
-	switch (val) {
-	case PVDD_1800:
-		return 1800;
-	case PVDD_2500:
-		return 2500;
-	case PVDD_3300:
-		return 3300;
-	default:
-		/* Should not happen. */
-		return -EINVAL;
-	}
+	return rzg2l_pwr_reg_val_to_ps(field_get(mask, val), caps);
 }
 
 static int rzg2l_set_power_source(struct rzg2l_pinctrl *pctrl, u32 pin, u32 caps, u32 ps)
 {
 	const struct rzg2l_hwcfg *hwcfg = pctrl->data->hwcfg;
 	const struct rzg2l_register_offsets *regs = &hwcfg->regs;
-	u8 poc_val, val, mask;
-	int pwr_reg;
+	const struct rzg2l_register_masks *masks = &hwcfg->masks;
+	u8 mask, val;
+	u16 offset;
+	int ret;
 
 	if (caps & PIN_CFG_SOFT_PS) {
 		pctrl->settings[pin].power_source = ps;
 		return 0;
 	}
 
-	switch (ps) {
-	case 1800:
-		poc_val = PVDD_1800;
-		break;
-	case 2500:
-		if (!(caps & (PIN_CFG_IO_VMC_ETH0 | PIN_CFG_IO_VMC_ETH1)))
-			return -EINVAL;
-		poc_val = PVDD_2500;
-		break;
-	case 3300:
-		poc_val = PVDD_3300;
-		break;
-	default:
-		return -EINVAL;
-	}
+	ret = rzg2l_ps_to_pwr_reg_val(&val, ps, caps);
+	if (ret)
+		return ret;
+
+	ret = rzg2l_caps_to_pwr_reg(regs, masks, caps, &offset, &mask);
+	if (ret)
+		return ret;
 
-	pwr_reg = rzg2l_caps_to_pwr_reg(regs, caps, &mask);
-	if (pwr_reg < 0)
-		return pwr_reg;
+	scoped_guard(raw_spinlock_irqsave, &pctrl->lock) {
+		u8 tmp = readb(pctrl->base + offset);
 
-	if (pwr_reg == OTHER_POC) {
-		scoped_guard(raw_spinlock_irqsave, &pctrl->lock) {
-			val = readb(pctrl->base + pwr_reg);
-			if (poc_val)
-				val |= mask;
-			else
-				val &= ~mask;
-			writeb(val, pctrl->base + pwr_reg);
-		}
-	} else {
-		writeb(poc_val, pctrl->base + pwr_reg);
+		tmp &= ~mask;
+		tmp |= field_prep(mask, val);
+		writeb(tmp, pctrl->base + offset);
 	}
 
 	pctrl->settings[pin].power_source = ps;
@@ -3795,6 +3837,11 @@ static const struct rzg2l_hwcfg rzg3l_hwcfg = {
 		.oen = 0x3018,
 		.other_poc = OTHER_POC,
 	},
+	.masks = {
+		.other_poc_pvdd1833_oth_awo_poc = BIT(0),
+		.other_poc_pvdd1833_oth_iso_poc = BIT(1),
+		.other_poc_wdtovf_n_poc = BIT(2),
+	},
 	.iolh_groupa_ua = {
 		/* 1v8 power source */
 		[RZG2L_IOLH_IDX_1V8] = 2200, 4400, 9000, 10000,
-- 
2.43.0