[PATCH] pinctrl: spacemit: fix NULL check in spacemit_pin_set_config

[Han Gao]

spacemit_pin_set_config() looks up the per-pin descriptor with
spacemit_get_pin() then checks the wrong variable for failure:

	const struct spacemit_pin *spin = spacemit_get_pin(pctrl, pin);
	...
	if (!pin)
		return -EINVAL;

	reg = spacemit_pin_to_reg(pctrl, spin->pin);

pin is an unsigned int pin id, where 0 (GPIO_0 / gmac0_rxdv on K3) is a
valid pin, so rejecting it here drops the PAD config write for the first
pin of every group. On K3 Pico-ITX the GMAC RGMII group lists pin 0 as
its first entry, so its drive-strength / bias configuration was silently
ignored.

The intended guard is against spacemit_get_pin() returning NULL when the
pin id isn't in the SoC's pin table. Check spin instead, which both
restores PAD setup for pin 0 and prevents a NULL deref on spin->pin.

Fixes: a83c29e1d145 ("pinctrl: spacemit: add support for SpacemiT K1 SoC")
Signed-off-by: Han Gao <gaohan at iscas.ac.cn>
---
 drivers/pinctrl/spacemit/pinctrl-k1.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pinctrl/spacemit/pinctrl-k1.c b/drivers/pinctrl/spacemit/pinctrl-k1.c
index b0be62b1c816..95024e2bb5a5 100644
--- a/drivers/pinctrl/spacemit/pinctrl-k1.c
+++ b/drivers/pinctrl/spacemit/pinctrl-k1.c
@@ -795,7 +795,7 @@ static int spacemit_pin_set_config(struct spacemit_pinctrl *pctrl,
 	void __iomem *reg;
 	unsigned int mux;
 
-	if (!pin)
+	if (!spin)
 		return -EINVAL;
 
 	reg = spacemit_pin_to_reg(pctrl, spin->pin);
-- 
2.47.3