src/soc/qualcomm/ipq40xx/timer.c

   1 /* SPDX-License-Identifier: BSD-3-Clause */
   2
   3 #include <device/mmio.h>
   4 #include <delay.h>
   5 #include <soc/iomap.h>
   6 #include <soc/ipq_timer.h>
   7 #include <timer.h>
   8
   9 #define GCNT_FREQ_MHZ           48
  10
  11 #define TIMER_TICKS(us)         (GCNT_FREQ_MHZ * (us))
  12 #define TIMER_USECS(ticks)      ((ticks) / GCNT_FREQ_MHZ)
  13
  14 /**
  15  * init_timer - initialize timer
  16  */
  17 void init_timer(void)
  18 {
  19         /* disable timer */
  20         write32(GCNT_CNTCR, 0);
  21
  22         /* Reset the counters to zero */
  23         write32(GCNT_GLB_CNTCV_LO, 0);
  24         write32(GCNT_GLB_CNTCV_HI, 0);
  25
  26         /* Enable timer */
  27         write32(GCNT_CNTCR, 1);
  28 }
  29
  30 static inline uint64_t read_gcnt_val(void)
  31 {
  32         uint32_t hi, lo;
  33
  34         do {
  35                 hi = read32(GCNT_CNTCV_HI);
  36                 lo = read32(GCNT_CNTCV_LO);
  37         } while (hi != read32(GCNT_CNTCV_HI));
  38
  39         return ((((uint64_t)hi) << 32) | lo);
  40 }
  41
  42 /**
  43  * udelay -  generates micro second delay.
  44  * @param usec: delay duration in microseconds
  45  */
  46 void udelay(unsigned int usec)
  47 {
  48         uint64_t expire;
  49
  50         expire = read_gcnt_val() + TIMER_TICKS(usec);
  51
  52         while (expire >= read_gcnt_val())
  53                 ;
  54 }
  55
  56 void timer_monotonic_get(struct mono_time *mt)
  57 {
  58         mono_time_set_usecs(mt, TIMER_USECS(read_gcnt_val()));
  59 }