raspberry3_bare/clock.c

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2022-03-17 22:35:47 +01:00
#include "clock.h"
#include "mbox.h"
#include "uart.h"
unsigned int getclock(uint32_t clkid, uint8_t max) {
mbox[0] = 8 * 4;
mbox[1] = MBOX_REQUEST;
mbox[2] = max > 0 ? MBOX_TAG_GETMAXCLK : MBOX_TAG_GETCLK;
mbox[3] = 8;
mbox[4] = 0;
mbox[5] = clkid;
mbox[6] = 0;
mbox[7] = MBOX_TAG_LAST;
if (mbox_call(MBOX_CH_PROP, mbox)) {
puts("Failed getting clock\n");
return 0;
} else {
return mbox[6];
}
}
int setmaxclock(uint32_t clkid)
{
uint32_t maxfreq = getclock(clkid, 1);
if (maxfreq != 0) {
return setclock(clkid, maxfreq);
}
return -1;
}
int setclock(uint32_t clkid, uint32_t freq)
{
mbox[0] = 9 * 4;
mbox[1] = MBOX_REQUEST;
mbox[2] = MBOX_TAG_SETCLK;
mbox[3] = 12;
mbox[4] = 0;
mbox[5] = clkid;
mbox[6] = freq;
mbox[7] = 0;
mbox[8] = MBOX_TAG_LAST;
if (mbox_call(MBOX_CH_PROP, mbox)) {
puts("Failed setting clock\n");
return -1;
}
return 0;
}