diff options
| -rw-r--r-- | bsp/drivers/fe300prci/fe300prci_driver.c | 63 | ||||
| -rw-r--r-- | bsp/drivers/fe300prci/fe300prci_driver.h | 10 | ||||
| -rw-r--r-- | bsp/drivers/plic/plic_driver.h | 1 |
3 files changed, 61 insertions, 13 deletions
diff --git a/bsp/drivers/fe300prci/fe300prci_driver.c b/bsp/drivers/fe300prci/fe300prci_driver.c index 9a16d5d..0e555a6 100644 --- a/bsp/drivers/fe300prci/fe300prci_driver.c +++ b/bsp/drivers/fe300prci/fe300prci_driver.c @@ -177,7 +177,7 @@ void PRCI_use_hfxosc(uint32_t finaldiv) // this way. // It returns the actual measured CPU frequency. -uint32_t PRCI_set_hfrosctrim_for_f_cpu(uint32_t f_cpu) +uint32_t PRCI_set_hfrosctrim_for_f_cpu(uint32_t f_cpu, PRCI_freq_target target ) { int hfrosctrim = 16; @@ -186,23 +186,62 @@ uint32_t PRCI_set_hfrosctrim_for_f_cpu(uint32_t f_cpu) // Ignore the first run (for icache reasons) uint32_t cpu_freq = PRCI_measure_mcycle_freq(1000, RTC_FREQ); cpu_freq = PRCI_measure_mcycle_freq(1000, RTC_FREQ); + int prev_trim = hfrosctrim; + int prev_freq = cpu_freq; if (cpu_freq > F_CPU) { - while((cpu_freq > F_CPU) && (hfrosctrim >= 0) ){ - PRCI_use_pll(0, 0, 1, 31, 1, 1, 4, hfrosctrim ); - cpu_freq = PRCI_measure_mcycle_freq(1000, RTC_FREQ); - hfrosctrim--; - } + while((cpu_freq > F_CPU) && (hfrosctrim > 0) ){ + prev_freq = cpu_freq; + prev_trim = hfrosctrim; + hfrosctrim--; + PRCI_use_pll(0, 0, 1, 31, 1, 1, 4, hfrosctrim ); + cpu_freq = PRCI_measure_mcycle_freq(1000, RTC_FREQ); + } + + // Check for over/undershoot + switch(target) { + case(PRCI_FREQ_CLOSEST): + if ((prev_freq - F_CPU) < (F_CPU - cpu_freq) && target == PRCI_FREQ_CLOSEST) { + PRCI_use_pll(0, 0, 1, 31, 1, 1, 4, prev_trim); + cpu_freq = PRCI_measure_mcycle_freq(1000, RTC_FREQ); + } + break; + case(PRCI_FREQ_OVERSHOOT): + PRCI_use_pll(0, 0, 1, 31, 1, 1, 4, prev_trim); + cpu_freq = PRCI_measure_mcycle_freq(1000, RTC_FREQ); + break; + //default: + // Do Nothing + } + return cpu_freq; } - - while(cpu_freq < F_CPU) { - if (hfrosctrim >= 0x20) { - break; - } + + while(cpu_freq < F_CPU && hfrosctrim < 0x20) { + prev_freq = cpu_freq; + prev_trim = hfrosctrim; + hfrosctrim ++; PRCI_use_pll(0, 0, 1, 31, 1, 1, 4, hfrosctrim ); cpu_freq = PRCI_measure_mcycle_freq(1000, RTC_FREQ); - hfrosctrim++; } + + + // Check for over/undershoot + switch(target) { + case(PRCI_FREQ_CLOSEST): + if ((F_CPU - prev_freq) < (cpu_freq - F_CPU)) { + PRCI_use_pll(0, 0, 1, 31, 1, 1, 4, prev_trim); + cpu_freq = PRCI_measure_mcycle_freq(1000, RTC_FREQ); + } + break; + case(PRCI_FREQ_UNDERSHOOT): + PRCI_use_pll(0, 0, 1, 31, 1, 1, 4, prev_trim); + cpu_freq = PRCI_measure_mcycle_freq(1000, RTC_FREQ); + break; + //default: + // Do Nothing + } + return cpu_freq; + } diff --git a/bsp/drivers/fe300prci/fe300prci_driver.h b/bsp/drivers/fe300prci/fe300prci_driver.h index 75dcf00..243e6de 100644 --- a/bsp/drivers/fe300prci/fe300prci_driver.h +++ b/bsp/drivers/fe300prci/fe300prci_driver.h @@ -7,6 +7,14 @@ __BEGIN_DECLS #include <unistd.h> +typedef enum prci_freq_target { + + PRCI_FREQ_OVERSHOOT, + PRCI_FREQ_CLOSEST, + PRCI_FREQ_UNDERSHOOT + +} PRCI_freq_target; + /* Measure and return the approximate frequency of the * CPU, as given by measuring the mcycle counter against * the mtime ticks. @@ -55,7 +63,7 @@ void PRCI_use_default_clocks(); * achievable with this function, and not all * are guaranteed to actually work. */ -uint32_t PRCI_set_hfrosctrim_for_f_cpu(uint32_t f_cpu); +uint32_t PRCI_set_hfrosctrim_for_f_cpu(uint32_t f_cpu, PRCI_freq_target target); __END_DECLS diff --git a/bsp/drivers/plic/plic_driver.h b/bsp/drivers/plic/plic_driver.h index b14b442..e7d609b 100644 --- a/bsp/drivers/plic/plic_driver.h +++ b/bsp/drivers/plic/plic_driver.h @@ -3,6 +3,7 @@ #ifndef PLIC_DRIVER_H #define PLIC_DRIVER_H + __BEGIN_DECLS #include "platform.h" |