diff options
Diffstat (limited to 'chip/nrf51/hwtimer.c')
-rw-r--r-- | chip/nrf51/hwtimer.c | 76 |
1 files changed, 46 insertions, 30 deletions
diff --git a/chip/nrf51/hwtimer.c b/chip/nrf51/hwtimer.c index 281b21211b..75079789dc 100644 --- a/chip/nrf51/hwtimer.c +++ b/chip/nrf51/hwtimer.c @@ -6,12 +6,8 @@ /* * Hardware timers driver. * - * nRF51x has one hardware counter, but 4 stand-alone capture/compare (CC) - * registers. - * - * CC(0) -- used to interrupt next clock event. - * CC(1) -- used to capture the current value. - * CC(2) -- used to detect overflow on virtual timer (not hardware). + * nRF51x has one fully functional hardware counter, but 4 stand-alone + * capture/compare (CC) registers. */ #include "common.h" @@ -20,11 +16,25 @@ #include "hwtimer.h" #include "registers.h" #include "task.h" +#include "util.h" #define CPUTS(outstr) cputs(CC_CLOCK, outstr) #define CPRINTF(format, args...) cprintf(CC_CLOCK, format, ## args) #define CPRINTS(format, args...) cprints(CC_CLOCK, format, ## args) +/* + * capture/compare (CC) registers: + * CC_INTERRUPT -- used to interrupt next clock event. + * CC_CURRENT -- used to capture the current value. + * CC_OVERFLOW -- used to detect overflow on virtual timer (not hardware). + */ + +#define CC_INTERRUPT 0 +#define CC_CURRENT 1 +#define CC_OVERFLOW 2 + +/* The nRF51 has 3 timers, use HWTIMER to specify which one is used here. */ +#define HWTIMER 0 static uint32_t last_deadline; /* cache of event set */ @@ -60,10 +70,11 @@ static uint32_t shift; void __hw_clock_event_set(uint32_t deadline) { last_deadline = deadline; - NRF51_TIMER0_CC0 = deadline - shift; + NRF51_TIMER_CC(HWTIMER, CC_INTERRUPT) = deadline - shift; /* enable interrupt */ - NRF51_TIMER0_INTENSET = 1 << NRF51_TIMER_COMPARE0_BIT; + NRF51_TIMER_INTENSET(HWTIMER) = + 1 << NRF51_TIMER_COMPARE_BIT(CC_INTERRUPT); } uint32_t __hw_clock_event_get(void) @@ -74,14 +85,15 @@ uint32_t __hw_clock_event_get(void) void __hw_clock_event_clear(void) { /* disable interrupt */ - NRF51_TIMER0_INTENCLR = 1 << NRF51_TIMER_COMPARE0_BIT; + NRF51_TIMER_INTENCLR(HWTIMER) = + 1 << NRF51_TIMER_COMPARE_BIT(CC_INTERRUPT); } uint32_t __hw_clock_source_read(void) { /* to capture the current value */ - NRF51_TIMER0_CAPTURE1 = 1; - return NRF51_TIMER0_CC1 + shift; + NRF51_TIMER_CAPTURE(HWTIMER, CC_CURRENT) = 1; + return NRF51_TIMER_CC(HWTIMER, CC_CURRENT) + shift; } void __hw_clock_source_set(uint32_t ts) @@ -89,17 +101,17 @@ void __hw_clock_source_set(uint32_t ts) shift = ts; /* reset counter to zero */ - NRF51_TIMER0_STOP = 1; - NRF51_TIMER0_CLEAR = 1; + NRF51_TIMER_STOP(HWTIMER) = 1; + NRF51_TIMER_CLEAR(HWTIMER) = 1; /* So that no interrupt until next __hw_clock_event_set() */ - NRF51_TIMER0_CC0 = ts - 1; + NRF51_TIMER_CC(HWTIMER, CC_INTERRUPT) = ts - 1; /* Update the overflow point */ - NRF51_TIMER0_CC2 = 0 - shift; + NRF51_TIMER_CC(HWTIMER, CC_OVERFLOW) = 0 - shift; /* Start the timer again */ - NRF51_TIMER0_START = 1; + NRF51_TIMER_START(HWTIMER) = 1; } @@ -109,55 +121,59 @@ void timer_irq(void) int overflow = 0; /* clear status */ - NRF51_TIMER0_COMPARE0 = 0; + NRF51_TIMER_COMPARE(HWTIMER, CC_INTERRUPT) = 0; - if (NRF51_TIMER0_COMPARE2) { - NRF51_TIMER0_COMPARE2 = 0; + if (NRF51_TIMER_COMPARE(HWTIMER, CC_OVERFLOW)) { + NRF51_TIMER_COMPARE(HWTIMER, CC_OVERFLOW) = 0; overflow = 1; } process_timers(overflow); } -DECLARE_IRQ(NRF51_PERID_TIMER0, timer_irq, 1); +/* DECLARE_IRQ doesn't like the NRF51_PERID_TIMER(n) macro */ +BUILD_ASSERT(NRF51_PERID_TIMER(HWTIMER) == NRF51_PERID_TIMER0); +DECLARE_IRQ(NRF51_PERID_TIMER0, timer_irq, 1); int __hw_clock_source_init(uint32_t start_t) { + /* Start the high freq crystal oscillator */ NRF51_CLOCK_HFCLKSTART = 1; /* TODO: check if the crystal oscillator is running (HFCLKSTAT) */ /* 32-bit timer mode */ - NRF51_TIMER0_MODE = NRF51_TIMER0_MODE_TIMER; - NRF51_TIMER0_BITMODE = NRF51_TIMER0_BITMODE_32; + NRF51_TIMER_MODE(HWTIMER) = NRF51_TIMER_MODE_TIMER; + NRF51_TIMER_BITMODE(HWTIMER) = NRF51_TIMER_BITMODE_32; /* * The external crystal oscillator is 16MHz (HFCLK). * Set the prescaler to 16 so that the timer counter is increasing * every micro-second (us). */ - NRF51_TIMER0_PRESCALER = 4; /* actual value is 2**4 = 16 */ + NRF51_TIMER_PRESCALER(HWTIMER) = 4; /* actual value is 2**4 = 16 */ /* Not to trigger interrupt until __hw_clock_event_set() is called. */ - NRF51_TIMER0_CC0 = 0xffffffff; + NRF51_TIMER_CC(HWTIMER, CC_INTERRUPT) = 0xffffffff; /* Set to 0 so that the next overflow can trigger timer_irq(). */ - NRF51_TIMER0_CC2 = 0; - NRF51_TIMER0_INTENSET = 1 << NRF51_TIMER_COMPARE2_BIT; + NRF51_TIMER_CC(HWTIMER, CC_OVERFLOW) = 0; + NRF51_TIMER_INTENSET(HWTIMER) = + 1 << NRF51_TIMER_COMPARE_BIT(CC_OVERFLOW); /* Clear the timer counter */ - NRF51_TIMER0_CLEAR = 1; + NRF51_TIMER_CLEAR(HWTIMER) = 1; /* Override the count with the start value now that counting has * started. */ __hw_clock_source_set(start_t); /* Enable interrupt */ - task_enable_irq(NRF51_PERID_TIMER0); + task_enable_irq(NRF51_PERID_TIMER(HWTIMER)); /* Start the timer */ - NRF51_TIMER0_START = 1; + NRF51_TIMER_START(HWTIMER) = 1; - return NRF51_PERID_TIMER0; + return NRF51_PERID_TIMER(HWTIMER); } |