timer: Add generic udelay() implementation

Add GENERIC_UDELAY Kconfig option so that a generic
udelay() implementation is provided utilizing the
monotonic timer. That way each board/chipset doesn't
need to duplicate the same udelay(). Additionally,
assume that GENERIC_UDELAY implies init_timer()
is not required.

BUG=None
BRANCH=None
TEST=Built nyan, ryu, and rambi. May need help testing.

Change-Id: I7f511a2324b5aa5d1b2959f4519be85a6a7360e8
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 1a85fbcad778933d13eaef545135abe7e4de46ed
Original-Change-Id: Idd26de19eefc91ee3b0ceddfb1bc2152e19fd8ab
Original-Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/219719
Original-Reviewed-by: Julius Werner <jwerner@chromium.org>
Original-Reviewed-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: http://review.coreboot.org/9334
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

2 files changed, 1 insertions, 27 deletions

diff --git a/src/soc/rockchip/rk3288/Kconfig b/src/soc/rockchip/rk3288/Kconfig
index 0865fe8f54..70951a5fa7 100644
--- a/src/soc/rockchip/rk3288/Kconfig
+++ b/src/soc/rockchip/rk3288/Kconfig
@@ -26,6 +26,7 @@ config SOC_ROCKCHIP_RK3288
 	select ARCH_RAMSTAGE_ARMV7
 	select CPU_HAS_BOOTBLOCK_INIT
 	select HAVE_MONOTONIC_TIMER
+	select GENERIC_UDELAY
 	select HAVE_UART_MEMORY_MAPPED
 	select HAVE_UART_SPECIAL
 	select BOOTBLOCK_CONSOLE
diff --git a/src/soc/rockchip/rk3288/timer.c b/src/soc/rockchip/rk3288/timer.c
index 7162482406..658f4d74f4 100644
--- a/src/soc/rockchip/rk3288/timer.c
+++ b/src/soc/rockchip/rk3288/timer.c
@@ -23,36 +23,9 @@
 #include <soc/timer.h>
 #include <timer.h>
 
-void init_timer(void)
-{
-}
-
 void rk3288_init_timer(void)
 {
 	write32(TIMER_LOAD_VAL, &timer7_ptr->timer_load_count0);
 	write32(TIMER_LOAD_VAL, &timer7_ptr->timer_load_count1);
 	write32(1, &timer7_ptr->timer_ctrl_reg);
 }
-
-/* delay x useconds */
-void udelay(unsigned usec)
-{
-	struct mono_time current, end;
-
-	timer_monotonic_get(&current);
-	end = current;
-	mono_time_add_usecs(&end, usec);
-
-	if (mono_time_after(&current, &end)) {
-		printk(BIOS_EMERG, "udelay: 0x%08x is impossibly large\n",
-				usec);
-		/* There's not much we can do if usec is too big. Use a long,
-		 * paranoid delay value and hope for the best... */
-		end = current;
-		mono_time_add_usecs(&end, USECS_PER_SEC);
-	}
-
-	while (mono_time_before(&current, &end))
-		timer_monotonic_get(&current);
-}
-