mec1322: clock: Use full-speed 48MHz processor clock during EC boot

EC boot / hash computing can be a bottleneck for system boot time.
Reduce this bottleneck by running our processor at 48 MHz through boot,
until vboot hashing of RW completes.

BUG=chrome-os-partner:49583
TEST=Boot chell, verify vboot hash completes within 1 sec of EC boot and
'cbmem' delta between 'vboot select&load kernel' and 'finished EC
verification' is reduced to ~250 ms (which includes sysjump time).
BRANCH=glados

Change-Id: I18d87e685b89decef761e51517bfcfc43dcf8ef0
Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/326792
Commit-Ready: Shawn N <shawnn@chromium.org>
Tested-by: Shawn N <shawnn@chromium.org>
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>

7 files changed, 28 insertions, 4 deletions

diff --git a/board/chell/board.h b/board/chell/board.h
index 6160e3e199..c143c48aa7 100644
--- a/board/chell/board.h
+++ b/board/chell/board.h
@@ -134,7 +134,7 @@
 #undef CONFIG_CONSOLE_CMDHELP
 
 #undef DEFERRABLE_MAX_COUNT
-#define DEFERRABLE_MAX_COUNT 14
+#define DEFERRABLE_MAX_COUNT 15
 
 #ifndef __ASSEMBLER__
 
diff --git a/board/glados/board.h b/board/glados/board.h
index 537126c765..c1891cb0d9 100644
--- a/board/glados/board.h
+++ b/board/glados/board.h
@@ -145,7 +145,7 @@
 #undef CONFIG_CONSOLE_CMDHELP
 
 #undef DEFERRABLE_MAX_COUNT
-#define DEFERRABLE_MAX_COUNT 15
+#define DEFERRABLE_MAX_COUNT 16
 
 #ifndef __ASSEMBLER__
 
diff --git a/board/kunimitsu/board.h b/board/kunimitsu/board.h
index 5603638bd1..63a6cf2243 100644
--- a/board/kunimitsu/board.h
+++ b/board/kunimitsu/board.h
@@ -134,7 +134,7 @@
 #define I2C_PORT_USB_CHARGER_2 MEC1322_I2C0_0
 
 #undef DEFERRABLE_MAX_COUNT
-#define DEFERRABLE_MAX_COUNT 15
+#define DEFERRABLE_MAX_COUNT 16
 
 #define CONFIG_ALS
 #define CONFIG_ALS_OPT3001
diff --git a/chip/mec1322/clock.c b/chip/mec1322/clock.c
index 9cef11686f..ba46e4e1a2 100644
--- a/chip/mec1322/clock.c
+++ b/chip/mec1322/clock.c
@@ -9,6 +9,7 @@
 #include "common.h"
 #include "console.h"
 #include "cpu.h"
+#include "hooks.h"
 #include "hwtimer.h"
 #include "registers.h"
 #include "shared_mem.h"
@@ -17,6 +18,7 @@
 #include "timer.h"
 #include "uart.h"
 #include "util.h"
+#include "vboot_hash.h"
 
 /* Console output macros */
 #define CPUTS(outstr) cputs(CC_CLOCK, outstr)
@@ -74,6 +76,23 @@ void clock_init(void)
 #endif
 }
 
+/**
+ * Speed through boot + vboot hash calculation, dropping our processor clock
+ * only after vboot hashing is completed.
+ */
+static void clock_turbo_disable(void)
+{
+#ifdef CONFIG_VBOOT_HASH
+	if (vboot_hash_in_progress())
+		hook_call_deferred(clock_turbo_disable, 100 * MSEC);
+	else
+#endif
+		/* Use 12 MHz processor clock for power savings */
+		MEC1322_PCR_PROC_CLK_CTL = 4;
+}
+DECLARE_HOOK(HOOK_INIT, clock_turbo_disable, HOOK_PRIO_INIT_VBOOT_HASH + 1);
+DECLARE_DEFERRED(clock_turbo_disable);
+
 #ifdef CONFIG_LOW_POWER_IDLE
 /**
  * initialization of Hibernation timer
diff --git a/chip/mec1322/lfw/ec_lfw.c b/chip/mec1322/lfw/ec_lfw.c
index 3bb3e31398..6824d10686 100644
--- a/chip/mec1322/lfw/ec_lfw.c
+++ b/chip/mec1322/lfw/ec_lfw.c
@@ -235,6 +235,9 @@ void lfw_main()
 	/* install vector table */
 	*((uintptr_t *) 0xe000ed08) = (uintptr_t) &hdr_int_vect;
 
+	/* Use 48 MHz processor clock to power through boot */
+	MEC1322_PCR_PROC_CLK_CTL = 1;
+
 #ifdef CONFIG_WATCHDOG
 	/* Reload watchdog which may be running in case of sysjump */
 	MEC1322_WDG_KICK = 1;
diff --git a/common/vboot_hash.c b/common/vboot_hash.c
index c200d15ba2..01af769ebf 100644
--- a/common/vboot_hash.c
+++ b/common/vboot_hash.c
@@ -235,7 +235,7 @@ static void vboot_hash_init(void)
 				 NULL, 0);
 	}
 }
-DECLARE_HOOK(HOOK_INIT, vboot_hash_init, HOOK_PRIO_DEFAULT);
+DECLARE_HOOK(HOOK_INIT, vboot_hash_init, HOOK_PRIO_INIT_VBOOT_HASH);
 
 #ifdef CONFIG_SAVE_VBOOT_HASH
 
diff --git a/include/hooks.h b/include/hooks.h
index c2b48ccd6c..3a7af06f3c 100644
--- a/include/hooks.h
+++ b/include/hooks.h
@@ -33,6 +33,8 @@ enum hook_priority {
 	HOOK_PRIO_INIT_PWM = HOOK_PRIO_FIRST + 6,
 	/* Extpower inits before modules which might use it (battery, LEDs) */
 	HOOK_PRIO_INIT_EXTPOWER = HOOK_PRIO_FIRST + 7,
+	/* Init VBOOT hash later, since it depends on deferred functions */
+	HOOK_PRIO_INIT_VBOOT_HASH = HOOK_PRIO_FIRST + 8,
 
 	/* Specific values to lump temperature-related hooks together */
 	HOOK_PRIO_TEMP_SENSOR = 6000,