src/soc/ti/am335x/timer.c

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #include <timer.h>
   4 #include <delay.h>
   5 #include <device/mmio.h>
   6
   7 #include "dmtimer.h"
   8 #include "clock.h"
   9
  10 struct am335x_dmtimer *dmtimer_2 = (struct am335x_dmtimer *)DMTIMER_2;
  11
  12 #define CLKSEL_M_OSC (0x01 << 0)
  13
  14 static uint32_t timer_raw_value(void)
  15 {
  16         return read32(&dmtimer_2->tcrr);
  17 }
  18
  19 void timer_monotonic_get(struct mono_time *mt)
  20 {
  21         mono_time_set_usecs(mt, timer_raw_value() / M_OSC_MHZ);
  22 }
  23
  24 void init_timer(void)
  25 {
  26         write32(&am335x_cm_dpll->clksel_timer2_clk, CLKSEL_M_OSC);
  27
  28         // Start the dmtimer in autoreload mode without any prescalers
  29         // With M_OSC at 24MHz, this gives a few minutes before the timer overflows
  30         write32(&dmtimer_2->tclr, TCLR_ST | TCLR_AR);
  31 }