pinctrl: renesas: Protect GPIO leftovers by CONFIG_PINCTRL_SH_FUNC_GPIO

On SuperH and ARM SH/R-Mobile SoCs, the pin control driver handles
GPIOs, too.  To reduce code size when compiling a kernel supporting only
modern SoCs, most, but not all, of the GPIO functionality is protected
by checks for CONFIG_PINCTRL_SH_FUNC_GPIO.

Factor out the remaining parts when not needed:
  1. sh_pfc_soc_info.{in,out}put describe GPIO pins that have input
     resp. output capabilities (SuperH and SH/R-Mobile).
  2. sh_pfc_soc_info.gpio_irq{,_size} describe the mapping from GPIO
     pins to interrupt numbers (SH/R-Mobile).
  3. sh_pfc_gpio_set_direction() configures GPIO direction, called from
     the GPIO driver through pinctrl_gpio_direction_{in,out}put()
     (SH/R-Mobile).  Unfortunately this function cannot just be moved to
     drivers/pinctrl/renesas/gpio.c, as it relies on knowledge of
     sh_pfc_pinctrl, which is internal to
     drivers/pinctrl/renesas/pinctrl.c.

While code size reduction is minimal, this does help in documenting
depencies.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20201028151637.1734130-9-geert+renesas@glider.be

drivers/pinctrl/renesas/core.c

@@ -315,6 +315,7 @@ int sh_pfc_config_mux(struct sh_pfc *pfc, unsigned mark, int pinmux_type)
 		range = NULL;
 		break;
 
+#ifdef CONFIG_PINCTRL_SH_PFC_GPIO
 	case PINMUX_TYPE_OUTPUT:
 		range = &pfc->info->output;
 		break;
@@ -322,6 +323,7 @@ int sh_pfc_config_mux(struct sh_pfc *pfc, unsigned mark, int pinmux_type)
 	case PINMUX_TYPE_INPUT:
 		range = &pfc->info->input;
 		break;
+#endif /* CONFIG_PINCTRL_SH_PFC_GPIO */
 
 	default:
 		return -EINVAL;

drivers/pinctrl/renesas/pinctrl.c

@@ -435,6 +435,7 @@ static void sh_pfc_gpio_disable_free(struct pinctrl_dev *pctldev,
 	spin_unlock_irqrestore(&pfc->lock, flags);
 }
 
+#ifdef CONFIG_PINCTRL_SH_PFC_GPIO
 static int sh_pfc_gpio_set_direction(struct pinctrl_dev *pctldev,
 				     struct pinctrl_gpio_range *range,
 				     unsigned offset, bool input)
@@ -462,6 +463,9 @@ static int sh_pfc_gpio_set_direction(struct pinctrl_dev *pctldev,
 	spin_unlock_irqrestore(&pfc->lock, flags);
 	return ret;
 }
+#else
+#define sh_pfc_gpio_set_direction	NULL
+#endif
 
 static const struct pinmux_ops sh_pfc_pinmux_ops = {
 	.get_functions_count	= sh_pfc_get_functions_count,

drivers/pinctrl/renesas/sh_pfc.h

@@ -270,8 +270,13 @@ struct sh_pfc_soc_info {
 	const char *name;
 	const struct sh_pfc_soc_operations *ops;
 
+#ifdef CONFIG_PINCTRL_SH_PFC_GPIO
 	struct pinmux_range input;
 	struct pinmux_range output;
+	const struct pinmux_irq *gpio_irq;
+	unsigned int gpio_irq_size;
+#endif
+
 	struct pinmux_range function;
 
 	const struct sh_pfc_pin *pins;
@@ -295,9 +300,6 @@ struct sh_pfc_soc_info {
 	const u16 *pinmux_data;
 	unsigned int pinmux_data_size;
 
-	const struct pinmux_irq *gpio_irq;
-	unsigned int gpio_irq_size;
-
 	u32 unlock_reg;
 };