pinctrl: renesas: r8a779a0: Fix GPIO function on I2C-capable pins

Unlike on R-Car Gen3 SoCs, setting a bit to zero in a GPIO / Peripheral
Function Select Register (GPSRn) on R-Car V3U is not always sufficient
to configure a pin for GPIO.  For I2C-capable pins, the I2C function
must also be explicitly disabled in the corresponding Module Select
Register (MODSELn).

Add the missing FN_SEL_I2Ci_0 function enums to the pinmux_data[] array
by temporarily overriding the GP_2_j_FN function enum to expand to two
enums: the original GP_2_j_FN enum to configure the GSPR register bits,
and the missing FN_SEL_I2Ci_0 enum to configure the MODSEL register
bits.

Fixes: 741a737 ("pinctrl: renesas: Initial R8A779A0 (V3U) PFC support")
Signed-off-by: Geert Uytterhoeven <[email protected]>
Link: https://lore.kernel.org/r/4611e29e7b105513883084c1d6dc39c3ac8b525c.1650610471.git.geert+renesas@glider.be

drivers/pinctrl/renesas/pfc-r8a779a0.c

@@ -629,7 +629,36 @@ enum {
 };
 
 static const u16 pinmux_data[] = {
+/* Using GP_2_[2-15] requires disabling I2C in MOD_SEL2 */
+#define GP_2_2_FN	GP_2_2_FN,	FN_SEL_I2C0_0
+#define GP_2_3_FN	GP_2_3_FN,	FN_SEL_I2C0_0
+#define GP_2_4_FN	GP_2_4_FN,	FN_SEL_I2C1_0
+#define GP_2_5_FN	GP_2_5_FN,	FN_SEL_I2C1_0
+#define GP_2_6_FN	GP_2_6_FN,	FN_SEL_I2C2_0
+#define GP_2_7_FN	GP_2_7_FN,	FN_SEL_I2C2_0
+#define GP_2_8_FN	GP_2_8_FN,	FN_SEL_I2C3_0
+#define GP_2_9_FN	GP_2_9_FN,	FN_SEL_I2C3_0
+#define GP_2_10_FN	GP_2_10_FN,	FN_SEL_I2C4_0
+#define GP_2_11_FN	GP_2_11_FN,	FN_SEL_I2C4_0
+#define GP_2_12_FN	GP_2_12_FN,	FN_SEL_I2C5_0
+#define GP_2_13_FN	GP_2_13_FN,	FN_SEL_I2C5_0
+#define GP_2_14_FN	GP_2_14_FN,	FN_SEL_I2C6_0
+#define GP_2_15_FN	GP_2_15_FN,	FN_SEL_I2C6_0
 	PINMUX_DATA_GP_ALL(),
+#undef GP_2_2_FN
+#undef GP_2_3_FN
+#undef GP_2_4_FN
+#undef GP_2_5_FN
+#undef GP_2_6_FN
+#undef GP_2_7_FN
+#undef GP_2_8_FN
+#undef GP_2_9_FN
+#undef GP_2_10_FN
+#undef GP_2_11_FN
+#undef GP_2_12_FN
+#undef GP_2_13_FN
+#undef GP_2_14_FN
+#undef GP_2_15_FN
 
 	PINMUX_SINGLE(MMC_D7),
 	PINMUX_SINGLE(MMC_D6),