80 lines
2.3 KiB
C
80 lines
2.3 KiB
C
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// See LICENSE file for license details
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#ifndef _FE300PRCI_DRIVER_H_
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#define _FE300PRCI_DRIVER_H_
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__BEGIN_DECLS
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#include <unistd.h>
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typedef enum prci_freq_target {
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PRCI_FREQ_OVERSHOOT,
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PRCI_FREQ_CLOSEST,
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PRCI_FREQ_UNDERSHOOT
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} PRCI_freq_target;
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/* Measure and return the approximate frequency of the
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* CPU, as given by measuring the mcycle counter against
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* the mtime ticks.
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*/
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uint32_t PRCI_measure_mcycle_freq(uint32_t mtime_ticks, uint32_t mtime_freq);
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/* Safely switch over to the HFROSC using the given div
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* and trim settings.
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*/
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void PRCI_use_hfrosc(int div, int trim);
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/* Safely switch over to the 16MHz HFXOSC,
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* applying the finaldiv clock divider (1 is the lowest
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* legal value).
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*/
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void PRCI_use_hfxosc(uint32_t finaldiv);
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/* Safely switch over to the PLL using the given
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* settings.
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*
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* Note that not all combinations of the inputs are actually
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* legal, and this function does not check for their
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* legality ("safely" means that this function won't turn off
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* or glitch the clock the CPU is actually running off, but
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* doesn't protect against you making it too fast or slow.)
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*/
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void PRCI_use_pll(int refsel, int bypass,
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int r, int f, int q, int finaldiv,
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int hfroscdiv, int hfrosctrim);
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/* Use the default clocks configured at reset.
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* This is ~16Mhz HFROSC and turns off the LFROSC
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* (on the current FE310 Dev Platforms, an external LFROSC is
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* used as it is more power efficient).
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*/
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void PRCI_use_default_clocks();
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/* This routine will adjust the HFROSC trim
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* while using HFROSC as the clock source,
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* measure the resulting frequency, then
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* use it as the PLL clock source,
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* in an attempt to get over, under, or close to the
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* requested frequency. It returns the actual measured
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* frequency.
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*
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* Note that the requested frequency must be within the
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* range supported by the PLL so not all values are
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* achievable with this function, and not all
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* are guaranteed to actually work. The PLL
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* is rated higher than the hardware.
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*
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* There is no check on the desired f_cpu frequency, it
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* is up to the user to specify something reasonable.
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*/
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uint32_t PRCI_set_hfrosctrim_for_f_cpu(uint32_t f_cpu, PRCI_freq_target target);
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__END_DECLS
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#endif
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