[PATCH] pinctrl: renesas: rzg2l: Validate pins before setting mux function

[PATCH] pinctrl: renesas: rzg2l: Validate pins before setting mux function

[Prabhakar]

From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Ensure only valid pins are configured by validating pin mappings before
setting the mux function.

Rename rzg2l_validate_gpio_pin() to rzg2l_validate_pin() to reflect its
broader purpose validating both GPIO pins and muxed pins. This helps
avoid invalid configurations.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
 drivers/pinctrl/renesas/pinctrl-rzg2l.c | 45 ++++++++++++++-----------
 1 file changed, 25 insertions(+), 20 deletions(-)

diff --git a/drivers/pinctrl/renesas/pinctrl-rzg2l.c b/drivers/pinctrl/renesas/pinctrl-rzg2l.c
index 59c32a0d87f1..2a10ae0bf5bd 100644
--- a/drivers/pinctrl/renesas/pinctrl-rzg2l.c
+++ b/drivers/pinctrl/renesas/pinctrl-rzg2l.c
@@ -493,6 +493,23 @@ static void rzv2h_pmc_writeb(struct rzg2l_pinctrl *pctrl, u8 val, u16 offset)
 	writeb(pwpr & ~PWPR_REGWE_A, pctrl->base + regs->pwpr);
 }
 
+static int rzg2l_validate_pin(struct rzg2l_pinctrl *pctrl,
+			      u64 cfg, u32 port, u8 bit)
+{
+	u8 pinmap = FIELD_GET(PIN_CFG_PIN_MAP_MASK, cfg);
+	u32 off = RZG2L_PIN_CFG_TO_PORT_OFFSET(cfg);
+	u64 data;
+
+	if (!(pinmap & BIT(bit)) || port >= pctrl->data->n_port_pins)
+		return -EINVAL;
+
+	data = pctrl->data->port_pin_configs[port];
+	if (off != RZG2L_PIN_CFG_TO_PORT_OFFSET(data))
+		return -EINVAL;
+
+	return 0;
+}
+
 static void rzg2l_pinctrl_set_pfc_mode(struct rzg2l_pinctrl *pctrl,
 				       u8 pin, u8 off, u8 func)
 {
@@ -536,6 +553,7 @@ static int rzg2l_pinctrl_set_mux(struct pinctrl_dev *pctldev,
 	unsigned int i, *psel_val;
 	struct group_desc *group;
 	const unsigned int *pins;
+	int ret;
 
 	func = pinmux_generic_get_function(pctldev, func_selector);
 	if (!func)
@@ -552,6 +570,10 @@ static int rzg2l_pinctrl_set_mux(struct pinctrl_dev *pctldev,
 		u32 off = RZG2L_PIN_CFG_TO_PORT_OFFSET(*pin_data);
 		u32 pin = RZG2L_PIN_ID_TO_PIN(pins[i]);
 
+		ret = rzg2l_validate_pin(pctrl, *pin_data, RZG2L_PIN_ID_TO_PORT(pins[i]), pin);
+		if (ret)
+			return ret;
+
 		dev_dbg(pctrl->dev, "port:%u pin: %u off:%x PSEL:%u\n",
 			RZG2L_PIN_ID_TO_PORT(pins[i]), pin, off, psel_val[i] - hwcfg->func_base);
 
@@ -806,23 +828,6 @@ static int rzg2l_dt_node_to_map(struct pinctrl_dev *pctldev,
 	return ret;
 }
 
-static int rzg2l_validate_gpio_pin(struct rzg2l_pinctrl *pctrl,
-				   u64 cfg, u32 port, u8 bit)
-{
-	u8 pinmap = FIELD_GET(PIN_CFG_PIN_MAP_MASK, cfg);
-	u32 off = RZG2L_PIN_CFG_TO_PORT_OFFSET(cfg);
-	u64 data;
-
-	if (!(pinmap & BIT(bit)) || port >= pctrl->data->n_port_pins)
-		return -EINVAL;
-
-	data = pctrl->data->port_pin_configs[port];
-	if (off != RZG2L_PIN_CFG_TO_PORT_OFFSET(data))
-		return -EINVAL;
-
-	return 0;
-}
-
 static u32 rzg2l_read_pin_config(struct rzg2l_pinctrl *pctrl, u32 offset,
 				 u8 bit, u32 mask)
 {
@@ -1287,7 +1292,7 @@ static int rzg2l_pinctrl_pinconf_get(struct pinctrl_dev *pctldev,
 	} else {
 		bit = RZG2L_PIN_ID_TO_PIN(_pin);
 
-		if (rzg2l_validate_gpio_pin(pctrl, *pin_data, RZG2L_PIN_ID_TO_PORT(_pin), bit))
+		if (rzg2l_validate_pin(pctrl, *pin_data, RZG2L_PIN_ID_TO_PORT(_pin), bit))
 			return -EINVAL;
 	}
 
@@ -1447,7 +1452,7 @@ static int rzg2l_pinctrl_pinconf_set(struct pinctrl_dev *pctldev,
 	} else {
 		bit = RZG2L_PIN_ID_TO_PIN(_pin);
 
-		if (rzg2l_validate_gpio_pin(pctrl, *pin_data, RZG2L_PIN_ID_TO_PORT(_pin), bit))
+		if (rzg2l_validate_pin(pctrl, *pin_data, RZG2L_PIN_ID_TO_PORT(_pin), bit))
 			return -EINVAL;
 	}
 
@@ -1687,7 +1692,7 @@ static int rzg2l_gpio_request(struct gpio_chip *chip, unsigned int offset)
 	u8 reg8;
 	int ret;
 
-	ret = rzg2l_validate_gpio_pin(pctrl, *pin_data, port, bit);
+	ret = rzg2l_validate_pin(pctrl, *pin_data, port, bit);
 	if (ret)
 		return ret;
 
-- 
2.49.0

Re: [PATCH] pinctrl: renesas: rzg2l: Validate pins before setting mux function

[Geert Uytterhoeven]

On Mon, 16 Jun 2025 at 15:27, Prabhakar <prabhakar.csengg@gmail.com> wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
>
> Ensure only valid pins are configured by validating pin mappings before
> setting the mux function.
>
> Rename rzg2l_validate_gpio_pin() to rzg2l_validate_pin() to reflect its
> broader purpose validating both GPIO pins and muxed pins. This helps
> avoid invalid configurations.
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
i.e. will queue in renesas-pinctrl for v6.17.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds