It is fairly common for the pins in a pin group to be a subset of the
pins in another pin group. Add a macro for defining a pin group that
refers to a subset of an array of pins. This allows pin groups to share
pin data, and thus save memory.
Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
drivers/pinctrl/renesas/sh_pfc.h | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/drivers/pinctrl/renesas/sh_pfc.h b/drivers/pinctrl/renesas/sh_pfc.h
index d6292a79282f198e..6f7fe21c982e5f48 100644
--- a/drivers/pinctrl/renesas/sh_pfc.h
+++ b/drivers/pinctrl/renesas/sh_pfc.h
@@ -58,6 +58,18 @@ struct sh_pfc_pin {
}
#define SH_PFC_PIN_GROUP(name) SH_PFC_PIN_GROUP_ALIAS(name, name)
+/*
+ * Define a pin group referring to a subset of an array of pins.
+ */
+#define SH_PFC_PIN_GROUP_SUBSET(_name, data, first, n) { \
+ .name = #_name, \
+ .pins = data##_pins + first, \
+ .mux = data##_mux + first, \
+ .nr_pins = n + \
+ BUILD_BUG_ON_ZERO(first + n > ARRAY_SIZE(data##_pins)) + \
+ BUILD_BUG_ON_ZERO(first + n > ARRAY_SIZE(data##_mux)), \
+}
+
struct sh_pfc_pin_group {
const char *name;
const unsigned int *pins;
--
2.25.1
