pinctrl: renesas: r8a7778: Use common R-Car bias handling

Currently, the rcar_pinmux_[gs]et_bias() helpers handle only SoCs that
have separate LSI Pin Pull-Enable (PUEN) and Pull-Up/Down Control (PUD)
registers, like R-Car Gen3 and RZ/G2.  Update the function to handle
SoCs that have only LSI Pin Pull-Up Control Register (PUPR), like R-Car
Gen1/Gen2 and RZ/G1.

Reduce code duplication by converting the R-Car M1A pin control driver
to use the common handler.

Note that this changes behavior in case the (invalid!) option
"bias-pull-down" is used in an R-Car M1A DTS: before, it was ignored
silently; after this change, it is considered the same as
"bias-pull-up".
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20201028151637.1734130-8-geert+renesas@glider.be

drivers/pinctrl/renesas/pfc-r8a7778.c

@@ -3116,42 +3116,9 @@ static const struct pinmux_bias_reg pinmux_bias_regs[] = {
 	{ /* sentinel */ },
 };
 
-static unsigned int r8a7778_pinmux_get_bias(struct sh_pfc *pfc,
-					    unsigned int pin)
-{
-	const struct pinmux_bias_reg *reg;
-	unsigned int bit;
-
-	reg = sh_pfc_pin_to_bias_reg(pfc, pin, &bit);
-	if (!reg)
-		return PIN_CONFIG_BIAS_DISABLE;
-
-	if (sh_pfc_read(pfc, reg->puen) & BIT(bit))
-		return PIN_CONFIG_BIAS_PULL_UP;
-	else
-		return PIN_CONFIG_BIAS_DISABLE;
-}
-
-static void r8a7778_pinmux_set_bias(struct sh_pfc *pfc, unsigned int pin,
-				   unsigned int bias)
-{
-	const struct pinmux_bias_reg *reg;
-	unsigned int bit;
-	u32 value;
-
-	reg = sh_pfc_pin_to_bias_reg(pfc, pin, &bit);
-	if (!reg)
-		return;
-
-	value = sh_pfc_read(pfc, reg->puen) & ~BIT(bit);
-	if (bias == PIN_CONFIG_BIAS_PULL_UP)
-		value |= BIT(bit);
-	sh_pfc_write(pfc, reg->puen, value);
-}
-
 static const struct sh_pfc_soc_operations r8a7778_pfc_ops = {
-	.get_bias = r8a7778_pinmux_get_bias,
-	.set_bias = r8a7778_pinmux_set_bias,
+	.get_bias = rcar_pinmux_get_bias,
+	.set_bias = rcar_pinmux_set_bias,
 };
 
 const struct sh_pfc_soc_info r8a7778_pinmux_info = {

drivers/pinctrl/renesas/pinctrl.c

@@ -835,7 +835,7 @@ unsigned int rcar_pinmux_get_bias(struct sh_pfc *pfc, unsigned int pin)
 
 	if (!(sh_pfc_read(pfc, reg->puen) & BIT(bit)))
 		return PIN_CONFIG_BIAS_DISABLE;
-	else if (sh_pfc_read(pfc, reg->pud) & BIT(bit))
+	else if (!reg->pud || (sh_pfc_read(pfc, reg->pud) & BIT(bit)))
 		return PIN_CONFIG_BIAS_PULL_UP;
 	else
 		return PIN_CONFIG_BIAS_PULL_DOWN;
@@ -856,10 +856,13 @@ void rcar_pinmux_set_bias(struct sh_pfc *pfc, unsigned int pin,
 	if (bias != PIN_CONFIG_BIAS_DISABLE)
 		enable |= BIT(bit);
 
+	if (reg->pud) {
 		updown = sh_pfc_read(pfc, reg->pud) & ~BIT(bit);
 		if (bias == PIN_CONFIG_BIAS_PULL_UP)
 			updown |= BIT(bit);
 
 		sh_pfc_write(pfc, reg->pud, updown);
+	}
+
 	sh_pfc_write(pfc, reg->puen, enable);
 }