[PATCH 8/8] clk: sunxi-ng: Allow the CCU core to be built as a module

[Samuel Holland <samuel@sholland.org>]

Like the individual CCU drivers, it can be beneficial for memory
consumption of cross-platform configurations to only load the CCU core
on the relevant platform. For example, a generic arm64 kernel sees the
following improvement when building the CCU core and drivers as modules:

  before:
    text      data     bss     dec       hex      filename
    13882360  5251670  360800  19494830  12977ae  vmlinux

  after:
    text      data     bss     dec       hex      filename
    13734787  5086442  360800  19182029  124b1cd  vmlinux

So the result is a 390KB total reduction in kernel image size.

The one early clock provider (sun5i) requires the core to be built in.

Now that loading the MMC driver will trigger loading the CCU core, the
MMC timing mode functions do not need a compile-time fallback.

Signed-off-by: Samuel Holland <samuel@sholland.org>
---
 drivers/clk/Makefile              |  2 +-
 drivers/clk/sunxi-ng/Kconfig      |  3 ++-
 drivers/clk/sunxi-ng/Makefile     | 33 +++++++++++++++++--------------
 drivers/clk/sunxi-ng/ccu_common.c |  3 +++
 drivers/mmc/host/Kconfig          |  1 +
 include/linux/clk/sunxi-ng.h      | 15 --------------
 6 files changed, 25 insertions(+), 32 deletions(-)

diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index 2b91d34c582b..009c4b41a45a 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -110,7 +110,7 @@ obj-$(CONFIG_PLAT_SPEAR)		+= spear/
 obj-y					+= sprd/
 obj-$(CONFIG_ARCH_STI)			+= st/
 obj-$(CONFIG_ARCH_SUNXI)		+= sunxi/
-obj-$(CONFIG_SUNXI_CCU)			+= sunxi-ng/
+obj-y					+= sunxi-ng/
 obj-$(CONFIG_ARCH_TEGRA)		+= tegra/
 obj-y					+= ti/
 obj-$(CONFIG_CLK_UNIPHIER)		+= uniphier/
diff --git a/drivers/clk/sunxi-ng/Kconfig b/drivers/clk/sunxi-ng/Kconfig
index cbae3612a9ef..ee383658ff4d 100644
--- a/drivers/clk/sunxi-ng/Kconfig
+++ b/drivers/clk/sunxi-ng/Kconfig
@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0-only
 config SUNXI_CCU
-	bool "Clock support for Allwinner SoCs"
+	tristate "Clock support for Allwinner SoCs"
 	depends on ARCH_SUNXI || COMPILE_TEST
 	select RESET_CONTROLLER
 	default ARCH_SUNXI
@@ -52,6 +52,7 @@ config SUN5I_CCU
 	bool "Support for the Allwinner sun5i family CCM"
 	default MACH_SUN5I
 	depends on MACH_SUN5I || COMPILE_TEST
+	depends on SUNXI_CCU=y
 
 config SUN6I_A31_CCU
 	tristate "Support for the Allwinner A31/A31s CCU"
diff --git a/drivers/clk/sunxi-ng/Makefile b/drivers/clk/sunxi-ng/Makefile
index 9ebf5920c93b..6e9eb004fca0 100644
--- a/drivers/clk/sunxi-ng/Makefile
+++ b/drivers/clk/sunxi-ng/Makefile
@@ -1,24 +1,27 @@
 # SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_SUNXI_CCU)		+= sunxi-ccu.o
+
 # Common objects
-obj-y				+= ccu_common.o
-obj-y				+= ccu_mmc_timing.o
-obj-y				+= ccu_reset.o
+sunxi-ccu-y			+= ccu_common.o
+sunxi-ccu-y			+= ccu_mmc_timing.o
+sunxi-ccu-y			+= ccu_reset.o
 
 # Base clock types
-obj-y				+= ccu_div.o
-obj-y				+= ccu_frac.o
-obj-y				+= ccu_gate.o
-obj-y				+= ccu_mux.o
-obj-y				+= ccu_mult.o
-obj-y				+= ccu_phase.o
-obj-y				+= ccu_sdm.o
+sunxi-ccu-y			+= ccu_div.o
+sunxi-ccu-y			+= ccu_frac.o
+sunxi-ccu-y			+= ccu_gate.o
+sunxi-ccu-y			+= ccu_mux.o
+sunxi-ccu-y			+= ccu_mult.o
+sunxi-ccu-y			+= ccu_phase.o
+sunxi-ccu-y			+= ccu_sdm.o
 
 # Multi-factor clocks
-obj-y				+= ccu_nk.o
-obj-y				+= ccu_nkm.o
-obj-y				+= ccu_nkmp.o
-obj-y				+= ccu_nm.o
-obj-y				+= ccu_mp.o
+sunxi-ccu-y			+= ccu_nk.o
+sunxi-ccu-y			+= ccu_nkm.o
+sunxi-ccu-y			+= ccu_nkmp.o
+sunxi-ccu-y			+= ccu_nm.o
+sunxi-ccu-y			+= ccu_mp.o
 
 # SoC support
 obj-$(CONFIG_SUNIV_F1C100S_CCU)	+= suniv-f1c100s-ccu.o
diff --git a/drivers/clk/sunxi-ng/ccu_common.c b/drivers/clk/sunxi-ng/ccu_common.c
index 3ab109582646..d9619ad32f5c 100644
--- a/drivers/clk/sunxi-ng/ccu_common.c
+++ b/drivers/clk/sunxi-ng/ccu_common.c
@@ -9,6 +9,7 @@
 #include <linux/clk-provider.h>
 #include <linux/device.h>
 #include <linux/iopoll.h>
+#include <linux/module.h>
 #include <linux/slab.h>
 
 #include "ccu_common.h"
@@ -213,3 +214,5 @@ void of_sunxi_ccu_probe(struct device_node *node, void __iomem *reg,
 		kfree(ccu);
 	}
 }
+
+MODULE_LICENSE("GPL");
diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 71313961cc54..1247c9455dea 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -964,6 +964,7 @@ config MMC_REALTEK_USB
 config MMC_SUNXI
 	tristate "Allwinner sunxi SD/MMC Host Controller support"
 	depends on ARCH_SUNXI || COMPILE_TEST
+	depends on SUNXI_CCU
 	help
 	  This selects support for the SD/MMC Host Controller on
 	  Allwinner sunxi SoCs.
diff --git a/include/linux/clk/sunxi-ng.h b/include/linux/clk/sunxi-ng.h
index 3cd14acde0a1..cf32123b39f5 100644
--- a/include/linux/clk/sunxi-ng.h
+++ b/include/linux/clk/sunxi-ng.h
@@ -6,22 +6,7 @@
 #ifndef _LINUX_CLK_SUNXI_NG_H_
 #define _LINUX_CLK_SUNXI_NG_H_
 
-#include <linux/errno.h>
-
-#ifdef CONFIG_SUNXI_CCU
 int sunxi_ccu_set_mmc_timing_mode(struct clk *clk, bool new_mode);
 int sunxi_ccu_get_mmc_timing_mode(struct clk *clk);
-#else
-static inline int sunxi_ccu_set_mmc_timing_mode(struct clk *clk,
-						bool new_mode)
-{
-	return -ENOTSUPP;
-}
-
-static inline int sunxi_ccu_get_mmc_timing_mode(struct clk *clk)
-{
-	return -ENOTSUPP;
-}
-#endif
 
 #endif
-- 
2.31.1