pinctrl: renesas: Add RZ/G2L PFC driver

This driver adds support for the pinctrl features of the GPIO/PFC module
in the Renesas RZ/G2L (R9A07G044) SoC.

A multi-function `rzg2l-pfc` driver is defined for UCLASS_NOP, which
binds the `rzg2l-pfc-pinctrl` UCLASS_PINCTRL driver dynamically. We also
define common macros and functions for the PFC in <renesas/rzg2l-pfc.h>.
This makes it easy to add an additional UCLASS_GPIO driver for the GPIO
functionality of this module in a follow-up patch.

This patch is based on the corresponding Linux v6.5 driver
(commit 52e12027d50affbf60c6c9c64db8017391b0c22e).

Signed-off-by: Paul Barker <paul.barker.ct@bp.renesas.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
diff --git a/include/renesas/rzg2l-pfc.h b/include/renesas/rzg2l-pfc.h
new file mode 100644
index 0000000..2df17ec
--- /dev/null
+++ b/include/renesas/rzg2l-pfc.h
@@ -0,0 +1,110 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * RZ/G2L Pin Function Controller
+ *
+ * Copyright (C) 2021-2023 Renesas Electronics Corp.
+ */
+
+#ifndef RENESAS_RZG2L_PFC_H
+#define RENESAS_RZG2L_PFC_H
+
+/* PIN capabilities */
+#define PIN_CFG_IOLH_A			BIT(0)
+#define PIN_CFG_IOLH_B			BIT(1)
+#define PIN_CFG_SR			BIT(2)
+#define PIN_CFG_IEN			BIT(3)
+#define PIN_CFG_PUPD			BIT(4)
+#define PIN_CFG_IO_VMC_SD0		BIT(5)
+#define PIN_CFG_IO_VMC_SD1		BIT(6)
+#define PIN_CFG_IO_VMC_QSPI		BIT(7)
+#define PIN_CFG_IO_VMC_ETH0		BIT(8)
+#define PIN_CFG_IO_VMC_ETH1		BIT(9)
+#define PIN_CFG_FILONOFF		BIT(10)
+#define PIN_CFG_FILNUM			BIT(11)
+#define PIN_CFG_FILCLKSEL		BIT(12)
+
+#define RZG2L_MPXED_PIN_FUNCS		(PIN_CFG_IOLH_A | \
+					 PIN_CFG_SR | \
+					 PIN_CFG_PUPD | \
+					 PIN_CFG_FILONOFF | \
+					 PIN_CFG_FILNUM | \
+					 PIN_CFG_FILCLKSEL)
+
+#define RZG2L_MPXED_ETH_PIN_FUNCS(x)	((x) | \
+					 PIN_CFG_FILONOFF | \
+					 PIN_CFG_FILNUM | \
+					 PIN_CFG_FILCLKSEL)
+
+/* GPIO port data macros:
+ * n indicates number of pins in the port, a is the register index
+ * and f is pin configuration capabilities supported.
+ */
+#define RZG2L_GPIO_PORT_PACK(n, a, f)	(((n) << 28) | ((a) << 20) | (f))
+#define RZG2L_GPIO_PORT_GET_PINCNT(x)	(((x) & GENMASK(30, 28)) >> 28)
+#define RZG2L_GPIO_PORT_GET_INDEX(x)	(((x) & GENMASK(26, 20)) >> 20)
+#define RZG2L_GPIO_PORT_GET_CFGS(x)	((x) & GENMASK(19, 0))
+
+/* Dedicated pin data macros:
+ * BIT(31) indicates dedicated pin, p is the register index while
+ * referencing to SR/IEN/IOLH/FILxx registers, b is the register bits
+ * (b * 8) and f is the pin configuration capabilities supported.
+ */
+#define RZG2L_SINGLE_PIN		BIT(31)
+#define RZG2L_SINGLE_PIN_PACK(p, b, f)	(RZG2L_SINGLE_PIN | \
+					 ((p) << 24) | ((b) << 20) | (f))
+#define RZG2L_SINGLE_PIN_GET_PORT_OFFSET(x)	(((x) & GENMASK(30, 24)) >> 24)
+#define RZG2L_SINGLE_PIN_GET_BIT(x)	(((x) & GENMASK(22, 20)) >> 20)
+#define RZG2L_SINGLE_PIN_GET_CFGS(x)	((x) & GENMASK(19, 0))
+
+/* Pinmux data encoded in the device tree uses:
+ * 16 lower bits [15:0] for pin identifier
+ * 16 higher bits [31:16] for pin mux function
+ */
+#define MUX_PIN_ID_MASK			GENMASK(15, 0)
+#define MUX_FUNC_MASK			GENMASK(31, 16)
+#define RZG2L_PINS_PER_PORT		8
+#define RZG2L_PINMUX_TO_PORT(conf)	(((conf) & MUX_PIN_ID_MASK) / RZG2L_PINS_PER_PORT)
+#define RZG2L_PINMUX_TO_PIN(conf)	(((conf) & MUX_PIN_ID_MASK) % RZG2L_PINS_PER_PORT)
+#define RZG2L_PINMUX_TO_FUNC(conf)	(((conf) & MUX_FUNC_MASK) >> 16)
+
+/* Register offsets and values. */
+#define P(n)			(0x0000 + 0x10 + (n))
+#define PM(n)			(0x0100 + 0x20 + (n) * 2)
+#define PMC(n)			(0x0200 + 0x10 + (n))
+#define PFC(n)			(0x0400 + 0x40 + (n) * 4)
+#define PIN(n)			(0x0800 + 0x10 + (n))
+#define IOLH(n)			(0x1000 + (n) * 8)
+#define IEN(n)			(0x1800 + (n) * 8)
+#define PWPR			0x3014
+#define SD_CH(n)		(0x3000 + (n) * 4)
+#define QSPI			0x3008
+
+#define PVDD_1800		1	/* I/O domain voltage <= 1.8V */
+#define PVDD_3300		0	/* I/O domain voltage >= 3.3V */
+
+#define PWPR_B0WI		BIT(7)	/* Bit Write Disable */
+#define PWPR_PFCWE		BIT(6)	/* PFC Register Write Enable */
+
+#define PM_MASK			0x03
+#define PVDD_MASK		0x01
+#define PFC_MASK		0x07
+#define IEN_MASK		0x01
+#define IOLH_MASK		0x03
+
+#define PM_HIGH_Z		0x0
+#define PM_INPUT		0x1
+#define PM_OUTPUT		0x2
+#define PM_OUTPUT_IEN		0x3
+
+struct rzg2l_pfc_data {
+	void __iomem *base;
+	uint num_dedicated_pins;
+	uint num_ports;
+	uint num_pins;
+	const u32 *gpio_configs;
+};
+
+int rzg2l_pfc_enable(struct udevice *dev);
+bool rzg2l_port_validate(const struct rzg2l_pfc_data *data, u32 port, u8 pin);
+
+#endif /* RENESAS_RZG2L_PFC_H */