Merge pull request #7175 from jamesbeyond/fm_mbed_hal

Enable new HAL us_ticker API on fast model MPS2 platform

Author: Cruz Monrreal

targets/TARGET_ARM_FM/TARGET_FVP_MPS2/us_ticker.c

@@ -16,77 +16,101 @@
 #include <stddef.h>
 #include "us_ticker_api.h"
 #include "PeripheralNames.h"
-
 #define US_TICKER_TIMER1      CMSDK_DUALTIMER1
 #define US_TICKER_TIMER2      CMSDK_DUALTIMER2
 #define US_TICKER_TIMER_IRQn  DUALTIMER_IRQn
 
-int us_ticker_inited = 0;
+/** mbed OS HAL API defined us_ticker as an increment ticker
+ *  MPS2 platform provided in SSE-200 are decrement tickers
+ *  with interrupt fired counter reaches 0.
+ *
+ *  So 2 Timers are used to construct mbed OS HAL ticker.
+ *  
+ *  TIMER1 is for counting, and returns inverted binary when read from it
+ *  TIMER1 will be kept in free-running mode (default, and not generate interrupts)
+ *  
+ *  TIMER2 is for generating interrupts
+ *  So TIMER2 is set to periodic mode, which start decrement counting form LOADVALUE generates interrupts at 0
+ *  and TIMER2 also set into one-shot mode, which counter halts when is reaches 0 
+ */
+ 
+static int us_ticker_inited = 0;
 
 void us_ticker_init(void)
 {
     if (us_ticker_inited) {
+        us_ticker_disable_interrupt();
         return;
     }
-    us_ticker_inited = 1;
 
-    US_TICKER_TIMER1->TimerControl = 0x0; // disable timer
-    US_TICKER_TIMER2->TimerControl = 0x00; // disable timer
-    US_TICKER_TIMER1->TimerLoad = 0xFFFFFFFF;
-    US_TICKER_TIMER2->TimerLoad = 0xFFFFFFFF;
+    US_TICKER_TIMER1->TimerControl  = 0x0ul; // disable TIMER1 and reset all control
+    US_TICKER_TIMER2->TimerControl  = 0x0ul; // disable TIMER2 and reset all control
+
+    US_TICKER_TIMER1->TimerLoad     = 0xFFFFFFFFul;
+    US_TICKER_TIMER2->TimerLoad     = 0xFFFFFFFFul;
+
+    US_TICKER_TIMER1->TimerControl |= CMSDK_DUALTIMER1_CTRL_SIZE_Msk; // set TIMER1 to 32 bit counter
+    US_TICKER_TIMER2->TimerControl |= CMSDK_DUALTIMER2_CTRL_SIZE_Msk; // set TIMER2 to 32 bit counter
 
-    US_TICKER_TIMER1->TimerControl = 0x62; // enable interrupt and set to 32 bit counter and set to periodic mode
-    US_TICKER_TIMER2->TimerControl = 0x42; // enable interrupt and set to 32 bit counter
+    US_TICKER_TIMER1->TimerControl |= 0x1 << CMSDK_DUALTIMER1_CTRL_PRESCALE_Pos; // set TIMER1 with 4 stages prescale
+    US_TICKER_TIMER2->TimerControl |= 0x1 << CMSDK_DUALTIMER2_CTRL_PRESCALE_Pos; // set TIMER2 with 4 stages prescale
 
-    US_TICKER_TIMER1->TimerControl |= 0x80; // enable counter
-    US_TICKER_TIMER2->TimerControl |= 0x80; // enable counter
+    US_TICKER_TIMER2->TimerControl |= CMSDK_DUALTIMER2_CTRL_MODE_Msk;     // set TIMER2 periodic mode
+    US_TICKER_TIMER2->TimerControl |= CMSDK_DUALTIMER2_CTRL_ONESHOOT_Msk; // set TIMER2 one-shot mode
+
+    US_TICKER_TIMER1->TimerControl |= CMSDK_DUALTIMER1_CTRL_EN_Msk; // enable TIMER1 counter
 
     NVIC_SetVector(US_TICKER_TIMER_IRQn, (uint32_t)us_ticker_irq_handler);
-    NVIC_EnableIRQ(US_TICKER_TIMER_IRQn);
+    us_ticker_inited = 1;
+}
+
+void us_ticker_free(void)
+{
+    US_TICKER_TIMER1->TimerControl  &= ~CMSDK_DUALTIMER1_CTRL_EN_Msk; // disable TIMER1
+    US_TICKER_TIMER2->TimerControl  &= ~CMSDK_DUALTIMER2_CTRL_EN_Msk; // disable TIMER2
+    us_ticker_disable_interrupt();
+    us_ticker_inited = 0;
 }
 
 uint32_t us_ticker_read()
 {
-    uint32_t return_value = 0;
-    if (!us_ticker_inited) {
-        us_ticker_init();
-    }
-    return_value = ((~US_TICKER_TIMER2->TimerValue) / 25);
-    return return_value;
+    return ~US_TICKER_TIMER1->TimerValue;
 }
 
 void us_ticker_set_interrupt(timestamp_t timestamp)
 {
-    if (!us_ticker_inited) {
-        us_ticker_init();
-    }
-
-    uint32_t delta = timestamp - us_ticker_read();
-    // enable interrupt
-    US_TICKER_TIMER1->TimerControl = 0x0; // disable timer
-    US_TICKER_TIMER1->TimerControl = 0x62; // enable interrupt and set to 32 bit counter and set to periodic mode
-    US_TICKER_TIMER1->TimerLoad = (delta) * 25; //initialise the timer value
-    US_TICKER_TIMER1->TimerControl |= 0x80; //enable timer
+    uint32_t delta =  timestamp - us_ticker_read();
+    US_TICKER_TIMER2->TimerControl &= ~CMSDK_DUALTIMER2_CTRL_EN_Msk;   // disable TIMER2
+    US_TICKER_TIMER2->TimerLoad = delta;                               // Set TIMER2 load value
+    US_TICKER_TIMER2->TimerControl |= CMSDK_DUALTIMER2_CTRL_INTEN_Msk; // enable TIMER2 interrupt
+    US_TICKER_TIMER2->TimerControl |= CMSDK_DUALTIMER2_CTRL_EN_Msk;    // enable TIMER2 counter
+    NVIC_EnableIRQ(US_TICKER_TIMER_IRQn);
 }
 
 void us_ticker_fire_interrupt(void)
 {
+    NVIC_EnableIRQ(US_TICKER_TIMER_IRQn);
     NVIC_SetPendingIRQ(US_TICKER_TIMER_IRQn);
 }
 
 
 void us_ticker_disable_interrupt(void)
 {
-
-    US_TICKER_TIMER1->TimerControl &= 0xDF;
-    US_TICKER_TIMER2->TimerControl &= 0xDF;
-
+    US_TICKER_TIMER2->TimerControl &= ~CMSDK_DUALTIMER2_CTRL_INTEN_Msk;
+    US_TICKER_TIMER2->TimerControl &= ~CMSDK_DUALTIMER2_CTRL_EN_Msk;  // disable TIMER2
+    NVIC_DisableIRQ(US_TICKER_TIMER_IRQn);
 }
 
 void us_ticker_clear_interrupt(void)
 {
+    US_TICKER_TIMER2->TimerIntClr = CMSDK_DUALTIMER2_INTCLR_Msk;
+}
 
-    US_TICKER_TIMER1->TimerIntClr = 0x1;
-    US_TICKER_TIMER2->TimerIntClr = 0x1;
-
+const ticker_info_t *us_ticker_get_info(void)
+{
+    static const ticker_info_t info = {
+        1562500,    // 4 stages prescaled from 25MHz (dived by 16)
+        32     // 32 bit counter
+    };
+    return &info;
 }

targets/targets.json

@@ -4190,7 +4190,7 @@
         "public": false,
         "supported_toolchains": ["GCC_ARM", "ARM", "IAR"],
         "OUTPUT_EXT": "elf",
-        "device_has": ["AACI", "ANALOGIN", "CLCD", "I2C", "INTERRUPTIN", "PORTIN", "PORTINOUT", "PORTOUT", "SERIAL", "SERIAL_FC", "SPI", "SPISLAVE", "TSC"],
+        "device_has": ["AACI", "ANALOGIN", "CLCD", "I2C", "INTERRUPTIN", "PORTIN", "PORTINOUT", "PORTOUT", "SERIAL", "SERIAL_FC", "SPI", "SPISLAVE", "TSC", "USTICKER"],
         "release_versions": ["5"]
     },
     "FVP_MPS2_M0": {