kernel: move regmap bloat out of the kernel image if it is only being used in modules

lede-commit: 96f39119815028073583e4fca3a9c5fe9141e998
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/base/regmap/Kconfig

@@ -3,9 +3,8 @@
 # subsystems should select the appropriate symbols.
 
 config REGMAP
-	default y if (REGMAP_I2C || REGMAP_SPI || REGMAP_SPMI || REGMAP_AC97 || REGMAP_MMIO || REGMAP_IRQ)
 	select IRQ_DOMAIN if REGMAP_IRQ
-	bool
+	tristate "Regmap"
 
 config REGCACHE_COMPRESSED
 	select LZO_COMPRESS
@@ -16,19 +15,25 @@ config REGMAP_AC97
 	tristate
 
 config REGMAP_I2C
-	tristate
+	tristate "Regmap I2C"
+	select REGMAP
 	depends on I2C
 
 config REGMAP_SPI
-	tristate
+	tristate "Regmap SPI"
+	select REGMAP
+	depends on SPI_MASTER
 	depends on SPI
 
 config REGMAP_SPMI
+	select REGMAP
 	tristate
 	depends on SPMI
 
 config REGMAP_MMIO
-	tristate
+	tristate "Regmap MMIO"
+	select REGMAP
 
 config REGMAP_IRQ
+	select REGMAP
 	bool

drivers/base/regmap/Makefile

 # For include/trace/define_trace.h to include trace.h
 CFLAGS_regmap.o := -I$(src)
 
-obj-$(CONFIG_REGMAP) += regmap.o regcache.o
-obj-$(CONFIG_REGMAP) += regcache-rbtree.o regcache-flat.o
-obj-$(CONFIG_REGCACHE_COMPRESSED) += regcache-lzo.o
-obj-$(CONFIG_DEBUG_FS) += regmap-debugfs.o
+regmap-core-objs = regmap.o regcache.o regcache-rbtree.o regcache-flat.o
+ifdef CONFIG_DEBUG_FS
+regmap-core-objs += regmap-debugfs.o
+endif
+ifdef CONFIG_REGCACHE_COMPRESSED
+regmap-core-objs += regcache-lzo.o
+endif
+obj-$(CONFIG_REGMAP) += regmap-core.o
 obj-$(CONFIG_REGMAP_AC97) += regmap-ac97.o
 obj-$(CONFIG_REGMAP_I2C) += regmap-i2c.o
 obj-$(CONFIG_REGMAP_SPI) += regmap-spi.o

drivers/base/regmap/regmap.c

@@ -13,6 +13,7 @@
 #include <linux/device.h>
 #include <linux/slab.h>
 #include <linux/export.h>
+#include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/err.h>
 #include <linux/of.h>
@@ -2913,3 +2914,5 @@ static int __init regmap_initcall(void)
 	return 0;
 }
 postcore_initcall(regmap_initcall);
+
+MODULE_LICENSE("GPL");

include/linux/regmap.h

@@ -135,7 +135,7 @@ struct reg_sequence {
 	pollret ?: ((cond) ? 0 : -ETIMEDOUT); \
 })
 
-#ifdef CONFIG_REGMAP
+#if IS_ENABLED(CONFIG_REGMAP)
 
 enum regmap_endian {
 	/* Unspecified -> 0 -> Backwards compatible default */