System tick timer additions and improvements Implement the remove callback functionna...

diff --git a/core/system.c b/core/system.c
index 5a9744a..7a966e9 100644 (file)
--- a/core/system.c
+++ b/core/system.c
@@ -122,6 +122,12 @@ void system_set_default_power_state(void)
        sys_ctrl->sys_AHB_clk_ctrl = LPC_SYS_ABH_CLK_CTRL_MEM_ALL;
 }
 
+/* Enter deep sleep.
+ * NOTE : entering deep sleep implies a lot of side effects. I'll try to lost them all here 
+ *        so this can be done right.
+ *
+ * Note : see remark about RTC and deep sleep in section 5.3.3 of UM10441
+ */
 void enter_deep_sleep(void)
 {
        struct lpc_sys_control* sys_ctrl = LPC_SYS_CONTROL;

diff --git a/core/systick.c b/core/systick.c
index a157ea5..6e289bc 100644 (file)
--- a/core/systick.c
+++ b/core/systick.c
@@ -70,8 +70,8 @@ void SysTick_Handler(void)
 }
 
 
-/* Register a callback to be called every 'period' system ticks with 'param' parameter.
- * returns the callback number, to be used to remove the callback from the table of callbacks.
+/* Register a callback to be called every 'period' system ticks.
+ * returns the callback number if registration was OK.
  * returns negative value on error.
  * The callback will get the "global_wrapping_system_ticks" as argument, which wraps every 50 days
  *   or so with a 1ms tick
@@ -93,16 +93,34 @@ int add_systick_callback(void (*callback) (uint32_t), uint16_t period)
        return -EBUSY;
 }
 
+int remove_systick_callback(void (*callback) (uint32_t))
+{
+       int i = 0;
+       for (i = 0; i < MAX_SYSTICK_CALLBACKS; i++) {
+               if (cbs[i].callback == callback) {
+                       cbs[i].callback = NULL;
+                       return 0;
+               }
+       }
+       return -EINVAL;
+}
 
 /***************************************************************************** */
 /* systick timer control function */
 
-/* Start the system tick timer */
+/* Start the system tick timer
+ * Starting the systick timer also resets the internal tick counters.
+ * If you need a value that goes beyond one start/stop cycle and accross resets,
+ *    then it's up to you to keep track of this using systick_get_tick_count() and/or
+ *    systick_get_clock_cycles().
+ */
 void systick_start(void)
 {
        struct lpc_system_tick* systick = LPC_SYSTICK;
        systick->value = 0;
        systick_running = 1;
+       global_wrapping_system_ticks = 0;
+       global_wrapping_system_clock_cycles = tick_reload;
        systick->control |= LPC_SYSTICK_CTRL_ENABLE;
 }
 /* Stop the system tick timer */
@@ -113,18 +131,43 @@ void systick_stop(void)
        systick_running = 0;
        systick->value = 0;
 }
-/* Reset the system tick timer, making it count down from the reload value again */
+/* Reset the system tick timer, making it count down from the reload value again
+ * Reseting the systick timer also resets the internal tick counters.
+ * If you need a value that goes beyond one start/stop cycle and accross resets,
+ *    then it's up to you to keep track of this using systick_get_tick_count() and/or
+ *    systick_get_clock_cycles().
+ */
 void systick_reset(void)
 {
        struct lpc_system_tick* systick = LPC_SYSTICK;
        systick->value = 0;
+       global_wrapping_system_ticks = 0;
+       global_wrapping_system_clock_cycles = tick_reload;
 }
 
+/* Get system tick timer current value (counts at get_main_clock() !) */
 uint32_t systick_get_timer_val(void)
 {
        struct lpc_system_tick* systick = LPC_SYSTICK;
        return systick->value;
 }
+
+/* Check if systick is running (return 1) or not (return 0) */
+uint32_t is_systick_running(void)
+{
+       return systick_running;
+}
+
+/* Get the system tick period in ms
+ * A vaue of 0 means the system tick timer has not been configured.
+ * Note : calls to msleep() or usleep() will configure the system tick timer
+ *        with a value of 1ms if it was not configured yet.
+ */
+uint32_t systick_get_tick_ms_period(void)
+{
+       return tick_ms;
+}
+
 /* Get the "timer wrapped" indicator.
  * Used in usleep() function.
  * Note : the first to call this function will get the right information.

diff --git a/include/core/system.h b/include/core/system.h
index 2cea777..b4340aa 100644 (file)
--- a/include/core/system.h
+++ b/include/core/system.h
@@ -118,16 +118,38 @@ void clkout_off(void);
 /*               System Tick Timer                                             */
 /***************************************************************************** */
 
-/* Start the system tick timer */
+/* Start the system tick timer
+ * Starting the systick timer also resets the internal tick counters.
+ * If you need a value that goes beyond one start/stop cycle and accross resets,
+ *    then it's up to you to keep track of this using systick_get_tick_count() and/or
+ *    systick_get_clock_cycles().
+ */
 void systick_start(void);
+
 /* Stop the system tick timer */
 void systick_stop(void);
-/* Reset the system tick timer, making it count down from the reload value again */
+
+/* Reset the system tick timer, making it count down from the reload value again
+ * Reseting the systick timer also resets the internal tick counters.
+ * If you need a value that goes beyond one start/stop cycle and accross resets,
+ *    then it's up to you to keep track of this using systick_get_tick_count() and/or
+ *    systick_get_clock_cycles().
+ */
 void systick_reset(void);
 
-/* Get system tick timer current value */
+/* Get system tick timer current value (counts at get_main_clock() !) */
 uint32_t systick_get_timer_val(void);
 
+/* Check if systick is running (return 1) or not (return 0) */
+uint32_t is_systick_running(void);
+
+/* Get the system tick period in ms
+ * A vaue of 0 means the system tick timer has not been configured.
+ * Note : calls to msleep() or usleep() will configure the system tick timer
+ *        with a value of 1ms if it was not configured yet.
+ */
+uint32_t systick_get_tick_ms_period(void);
+
 /* Get the number of system ticks ... since last wrapping of the counter, which
  * is about 50 days with a 1ms system tick. */
 uint32_t systick_get_tick_count(void);
@@ -145,13 +167,15 @@ void systick_timer_on(uint32_t ms);
 void systick_timer_off(void);
 
 /* Register a callback to be called every 'period' system ticks.
- * returns the callback number, to be used to remove the callback from the table of callbacks.
+ * returns the callback number if registration was OK.
  * returns negative value on error.
  * The callback will get the "global_wrapping_system_ticks" as argument, which wraps every 50 days
  *   or so with a 1ms tick
  */
 #define MAX_SYSTICK_CALLBACKS  4
 int add_systick_callback(void (*callback) (uint32_t), uint16_t period);
+/* Remove a registered callback, given the callback address used to register it. */
+int remove_systick_callback(void (*callback) (uint32_t));
 
 /***************************************************************************** */
 /* Sleeping functions : these use systick */