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// See LICENSE file for license details
#ifndef _PRCI_DRIVER_H_
#define _PRCI_DRIVER_H_
__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.
*/
uint32_t PRCI_measure_mcycle_freq(uint32_t mtime_ticks, uint32_t mtime_freq);
unsigned long PRCI_get_cpu_freq();
/* Safely switch over to the HFROSC using the given div
* and trim settings.
*/
void PRCI_use_hfrosc(int div, int trim);
/* Safely switch over to the 16MHz HFXOSC,
* applying the finaldiv clock divider (1 is the lowest
* legal value).
*/
void PRCI_use_hfxosc(uint32_t finaldiv);
/* Safely switch over to the PLL using the given
* settings.
*
* Note that not all combinations of the inputs are actually
* legal, and this function does not check for their
* legality ("safely" means that this function won't turn off
* or glitch the clock the CPU is actually running off, but
* doesn't protect against you making it too fast or slow.)
*/
void PRCI_use_pll(int refsel, int bypass,
int r, int f, int q, int finaldiv,
int hfroscdiv, int hfrosctrim);
/* Use the default clocks configured at reset.
* This is ~16Mhz HFROSC and turns off the LFROSC
* (on the current FE310 Dev Platforms, an external LFROSC is
* used as it is more power efficient).
*/
void PRCI_use_default_clocks();
/* This routine will adjust the HFROSC trim
* while using HFROSC as the clock source,
* measure the resulting frequency, then
* use it as the PLL clock source,
* in an attempt to get over, under, or close to the
* requested frequency. It returns the actual measured
* frequency.
*
* Note that the requested frequency must be within the
* range supported by the PLL so not all values are
* achievable with this function, and not all
* are guaranteed to actually work. The PLL
* is rated higher than the hardware.
*
* There is no check on the desired f_cpu frequency, it
* is up to the user to specify something reasonable.
*/
uint32_t PRCI_set_hfrosctrim_for_f_cpu(uint32_t f_cpu, PRCI_freq_target target);
__END_DECLS
#endif
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