imx233: simplify timrot API

The old timrot setup API was very low-level and unfriendly. The new one
makes in easier to select the frequency source. Use to simplify timer
and kernel timer code.

Change-Id: Iffcdf11c00e925be9ec8d9a4efc74b197b6bd2aa

5 files changed, 74 insertions, 11 deletions

diff --git a/firmware/target/arm/imx233/kernel-imx233.c b/firmware/target/arm/imx233/kernel-imx233.c
index 199015f564..0652d6e640 100644
--- a/firmware/target/arm/imx233/kernel-imx233.c
+++ b/firmware/target/arm/imx233/kernel-imx233.c
@@ -34,9 +34,7 @@ static void tick_timer(void)
 void tick_start(unsigned int interval_in_ms)
 {
     /* use the 1-kHz XTAL clock source */
-    imx233_timrot_setup(TIMER_TICK, true, interval_in_ms,
-        BV_TIMROT_TIMCTRLn_SELECT__1KHZ_XTAL, BV_TIMROT_TIMCTRLn_PRESCALE__DIV_BY_1,
-        false, &tick_timer);
+    imx233_timrot_setup_simple(TIMER_TICK, true, interval_in_ms, TIMER_SRC_1KHZ, &tick_timer);
 }
 
 void arbiter_init(struct channel_arbiter_t *a, unsigned count)
diff --git a/firmware/target/arm/imx233/system-imx233.c b/firmware/target/arm/imx233/system-imx233.c
index 666b9fedf4..b2ece3be61 100644
--- a/firmware/target/arm/imx233/system-imx233.c
+++ b/firmware/target/arm/imx233/system-imx233.c
@@ -67,9 +67,8 @@ static void good_dog(void)
 {
     imx233_rtc_reset_watchdog(WATCHDOG_HW_DELAY * 1000 / HZ); /* ms */
     imx233_rtc_enable_watchdog(true);
-    imx233_timrot_setup(TIMER_WATCHDOG, false, WATCHDOG_SW_DELAY * 1000 / HZ,
-        BV_TIMROT_TIMCTRLn_SELECT__1KHZ_XTAL, BV_TIMROT_TIMCTRLn_PRESCALE__DIV_BY_1,
-        false, &woof_woof);
+    imx233_timrot_setup_simple(TIMER_WATCHDOG, false, WATCHDOG_SW_DELAY * 1000 / HZ,
+        TIMER_SRC_1KHZ, &woof_woof);
     imx233_timrot_set_priority(TIMER_WATCHDOG, ICOLL_PRIO_WATCHDOG);
 }
 
diff --git a/firmware/target/arm/imx233/timer-imx233.c b/firmware/target/arm/imx233/timer-imx233.c
index bcadc82f2c..57d38c01a6 100644
--- a/firmware/target/arm/imx233/timer-imx233.c
+++ b/firmware/target/arm/imx233/timer-imx233.c
@@ -49,14 +49,11 @@ bool timer_set(long cycles, bool start)
 
 bool timer_start(IF_COP_VOID(int core))
 {
-    imx233_timrot_setup(TIMER_USER, true, timer_cycles,
-        BV_TIMROT_TIMCTRLn_SELECT__32KHZ_XTAL, BV_TIMROT_TIMCTRLn_PRESCALE__DIV_BY_1,
-        false, &timer_fn);
+    imx233_timrot_setup_simple(TIMER_USER, true, timer_cycles, TIMER_SRC_32KHZ, &timer_fn);
     return true;
 }
 
 void timer_stop(void)
 {
-    imx233_timrot_setup(TIMER_USER, false, 0, BV_TIMROT_TIMCTRLn_SELECT__NEVER_TICK,
-        BV_TIMROT_TIMCTRLn_PRESCALE__DIV_BY_1, false, NULL);
+    imx233_timrot_setup_simple(TIMER_USER, false, 0, TIMER_SRC_STOP, NULL);
 }
diff --git a/firmware/target/arm/imx233/timrot-imx233.c b/firmware/target/arm/imx233/timrot-imx233.c
index 7c5e60c30e..91f24924d6 100644
--- a/firmware/target/arm/imx233/timrot-imx233.c
+++ b/firmware/target/arm/imx233/timrot-imx233.c
@@ -65,6 +65,49 @@ void imx233_timrot_set_priority(unsigned timer_nr, unsigned prio)
     imx233_icoll_set_priority(INT_SRC_TIMER(timer_nr), prio);
 }
 
+static unsigned map_src(enum imx233_timrot_src_t src, unsigned *prescale)
+{
+    *prescale = BV_TIMROT_TIMCTRLn_PRESCALE__DIV_BY_1;
+    switch(src)
+    {
+        case TIMER_SRC_24MHZ:
+            return BV_TIMROT_TIMCTRLn_SELECT__TICK_ALWAYS;
+        case TIMER_SRC_12MHZ:
+            *prescale = BV_TIMROT_TIMCTRLn_PRESCALE__DIV_BY_2;
+            return BV_TIMROT_TIMCTRLn_SELECT__TICK_ALWAYS;
+        case TIMER_SRC_6MHZ:
+            *prescale = BV_TIMROT_TIMCTRLn_PRESCALE__DIV_BY_4;
+            return BV_TIMROT_TIMCTRLn_SELECT__TICK_ALWAYS;
+        case TIMER_SRC_3MHZ:
+            *prescale = BV_TIMROT_TIMCTRLn_PRESCALE__DIV_BY_8;
+            return BV_TIMROT_TIMCTRLn_SELECT__TICK_ALWAYS;
+        case TIMER_SRC_32KHZ:
+            return BV_TIMROT_TIMCTRLn_SELECT__32KHZ_XTAL;
+        case TIMER_SRC_8KHZ:
+            return BV_TIMROT_TIMCTRLn_SELECT__8KHZ_XTAL;
+        case TIMER_SRC_4KHZ:
+            return BV_TIMROT_TIMCTRLn_SELECT__4KHZ_XTAL;
+        case TIMER_SRC_1KHZ:
+            return BV_TIMROT_TIMCTRLn_SELECT__1KHZ_XTAL;
+        case TIMER_SRC_STOP:
+        default:
+            return BV_TIMROT_TIMCTRLn_SELECT__NEVER_TICK;
+    }
+}
+
+void imx233_timrot_setup_simple(unsigned timer_nr, bool periodic, unsigned count,
+    enum imx233_timrot_src_t src, imx233_timer_fn_t fn)
+{
+    unsigned prescale;
+    unsigned hw_src = map_src(src, &prescale);
+    imx233_timrot_setup(timer_nr, periodic, count, hw_src, prescale, false, fn);
+}
+
+unsigned imx233_timrot_get_count(unsigned timer_nr)
+{
+    return BF_RD(TIMROT_TIMCOUNTn(timer_nr), RUNNING_COUNT);
+}
+
 struct imx233_timrot_info_t imx233_timrot_get_info(unsigned timer_nr)
 {
     struct imx233_timrot_info_t info;
diff --git a/firmware/target/arm/imx233/timrot-imx233.h b/firmware/target/arm/imx233/timrot-imx233.h
index 778cd1add9..0add64e9ce 100644
--- a/firmware/target/arm/imx233/timrot-imx233.h
+++ b/firmware/target/arm/imx233/timrot-imx233.h
@@ -25,6 +25,7 @@
 #include "cpu.h"
 #include "icoll-imx233.h"
 
+/* WARNING timrot code assumes APBX is running at 24MHz */
 /* list of timers */
 enum
 {
@@ -33,6 +34,20 @@ enum
     TIMER_WATCHDOG, /* for watchdog */
 };
 
+/* timer sources */
+enum imx233_timrot_src_t
+{
+    TIMER_SRC_24MHZ,
+    TIMER_SRC_12MHZ,
+    TIMER_SRC_6MHZ,
+    TIMER_SRC_3MHZ,
+    TIMER_SRC_32KHZ,
+    TIMER_SRC_8KHZ,
+    TIMER_SRC_4KHZ,
+    TIMER_SRC_1KHZ,
+    TIMER_SRC_STOP
+};
+
 struct imx233_timrot_info_t
 {
     unsigned fixed_count, run_count;
@@ -45,10 +60,21 @@ struct imx233_timrot_info_t
 
 typedef void (*imx233_timer_fn_t)(void);
 
+/* maximum count for non-periodic timers, add one for periodic timers */
+#define IMX233_TIMROT_MAX_COUNT 0xffff
+
 void imx233_timrot_init(void);
+/* low-level function all-in-one function */
 void imx233_timrot_setup(unsigned timer_nr, bool reload, unsigned count,
     unsigned src, unsigned prescale, bool polarity, imx233_timer_fn_t fn);
+/* change interrupt priority */
 void imx233_timrot_set_priority(unsigned timer_nr, unsigned prio);
+/* simple setup function */
+void imx233_timrot_setup_simple(unsigned timer_nr, bool periodic, unsigned count,
+    enum imx233_timrot_src_t src, imx233_timer_fn_t fn);
+/* get timer count */
+unsigned imx233_timrot_get_count(unsigned timer_nr);
+/* update timer running count */
 struct imx233_timrot_info_t imx233_timrot_get_info(unsigned timer_nr);
 
 #endif /* TIMROT_IMX233_H */