pinctrl: sh-pfc: Add sh_pfc_pin_to_bias_reg() helper

Add a helper to look up bias registers and bit number for a specific
pin, using the generic bias register description.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

drivers/pinctrl/sh-pfc/core.c

@@ -404,6 +404,26 @@ sh_pfc_pin_to_bias_info(const struct sh_pfc_bias_info *info,
 	return NULL;
 }
 
+const struct pinmux_bias_reg *
+sh_pfc_pin_to_bias_reg(const struct sh_pfc *pfc, unsigned int pin,
+		       unsigned int *bit)
+{
+	unsigned int i, j;
+
+	for (i = 0; pfc->info->bias_regs[i].puen; i++) {
+		for (j = 0; j < ARRAY_SIZE(pfc->info->bias_regs[i].pins); j++) {
+			if (pfc->info->bias_regs[i].pins[j] == pin) {
+				*bit = j;
+				return &pfc->info->bias_regs[i];
+			}
+		}
+	}
+
+	WARN_ONCE(1, "Pin %u is not in bias info list\n", pin);
+
+	return NULL;
+}
+
 static int sh_pfc_init_ranges(struct sh_pfc *pfc)
 {
 	struct sh_pfc_pin_range *range;

drivers/pinctrl/sh-pfc/core.h

@@ -35,5 +35,8 @@ int sh_pfc_config_mux(struct sh_pfc *pfc, unsigned mark, int pinmux_type);
 const struct sh_pfc_bias_info *
 sh_pfc_pin_to_bias_info(const struct sh_pfc_bias_info *info,
 			unsigned int num, unsigned int pin);
+const struct pinmux_bias_reg *
+sh_pfc_pin_to_bias_reg(const struct sh_pfc *pfc, unsigned int pin,
+		       unsigned int *bit);
 
 #endif /* __SH_PFC_CORE_H__ */