lib: utils/timer: Use kconfig for enabling/disabling drivers

We update timer drivers makefile to use kconfig for enabling/disabling
drivers. To avoid compile errors, we also enable appropriate timer
drivers for each platform.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Tested-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Atish Patra <atishp@rivosinc.com>
Tested-by: Atish Patra <atishp@rivosinc.com>

lib/utils/Kconfig

@@ -8,4 +8,6 @@ source "$(OPENSBI_SRC_DIR)/lib/utils/serial/Kconfig"
 
 source "$(OPENSBI_SRC_DIR)/lib/utils/sys/Kconfig"
 
+source "$(OPENSBI_SRC_DIR)/lib/utils/timer/Kconfig"
+
 endmenu

lib/utils/timer/Kconfig

@@ -0,0 +1,22 @@
+# SPDX-License-Identifier: BSD-2-Clause
+
+menu "Timer Device Support"
+
+config FDT_TIMER
+	bool "FDT based timer drivers"
+	default n
+
+if FDT_TIMER
+
+config FDT_TIMER_MTIMER
+	bool "ACLINT MTIMER FDT driver"
+	select TIMER_MTIMER
+	default n
+
+endif
+
+config TIMER_MTIMER
+	bool "ACLINT MTIMER support"
+	default n
+
+endmenu

lib/utils/timer/objects.mk

@@ -7,10 +7,10 @@
 #   Anup Patel <anup.patel@wdc.com>
 #
 
-libsbiutils-objs-y += timer/aclint_mtimer.o
+libsbiutils-objs-$(CONFIG_TIMER_MTIMER) += timer/aclint_mtimer.o
 
-libsbiutils-objs-y += timer/fdt_timer.o
-libsbiutils-objs-y += timer/fdt_timer_drivers.o
+libsbiutils-objs-$(CONFIG_FDT_TIMER) += timer/fdt_timer.o
+libsbiutils-objs-$(CONFIG_FDT_TIMER) += timer/fdt_timer_drivers.o
 
-carray-fdt_timer_drivers-y += fdt_timer_mtimer
-libsbiutils-objs-y += timer/fdt_timer_mtimer.o
+carray-fdt_timer_drivers-$(CONFIG_FDT_TIMER_MTIMER) += fdt_timer_mtimer
+libsbiutils-objs-$(CONFIG_FDT_TIMER_MTIMER) += timer/fdt_timer_mtimer.o