arch/arm/cpu/arm1176/tnetv107x/timer.c

   1 /*
   2  * TNETV107X: Timer implementation
   3  *
   4  * SPDX-License-Identifier:     GPL-2.0+
   5  */
   6
   7 #include <common.h>
   8 #include <asm/io.h>
   9 #include <asm/arch/clock.h>
  10
  11 struct timer_regs {
  12         u_int32_t pid12;
  13         u_int32_t pad[3];
  14         u_int32_t tim12;
  15         u_int32_t tim34;
  16         u_int32_t prd12;
  17         u_int32_t prd34;
  18         u_int32_t tcr;
  19         u_int32_t tgcr;
  20         u_int32_t wdtcr;
  21 };
  22
  23 #define regs ((struct timer_regs *)CONFIG_SYS_TIMERBASE)
  24
  25 #define TIMER_LOAD_VAL  (CONFIG_SYS_HZ_CLOCK / CONFIG_SYS_HZ)
  26 #define TIM_CLK_DIV     16
  27
  28 static ulong timestamp;
  29 static ulong lastinc;
  30
  31 int timer_init(void)
  32 {
  33         clk_enable(TNETV107X_LPSC_TIMER0);
  34
  35         lastinc = timestamp = 0;
  36
  37         /* We are using timer34 in unchained 32-bit mode, full speed */
  38         __raw_writel(0x0, &regs->tcr);
  39         __raw_writel(0x0, &regs->tgcr);
  40         __raw_writel(0x06 | ((TIM_CLK_DIV - 1) << 8), &regs->tgcr);
  41         __raw_writel(0x0, &regs->tim34);
  42         __raw_writel(TIMER_LOAD_VAL, &regs->prd34);
  43         __raw_writel(2 << 22, &regs->tcr);
  44
  45         return 0;
  46 }
  47
  48 static ulong get_timer_raw(void)
  49 {
  50         ulong now = __raw_readl(&regs->tim34);
  51
  52         if (now >= lastinc)
  53                 timestamp += now - lastinc;
  54         else
  55                 timestamp += now + TIMER_LOAD_VAL - lastinc;
  56
  57         lastinc = now;
  58
  59         return timestamp;
  60 }
  61
  62 ulong get_timer(ulong base)
  63 {
  64         return (get_timer_raw() / (TIMER_LOAD_VAL / TIM_CLK_DIV)) - base;
  65 }
  66
  67 unsigned long long get_ticks(void)
  68 {
  69         return get_timer(0);
  70 }
  71
  72 void __udelay(unsigned long usec)
  73 {
  74         ulong tmo;
  75         ulong endtime;
  76         signed long diff;
  77
  78         tmo = CONFIG_SYS_HZ_CLOCK / 1000;
  79         tmo *= usec;
  80         tmo /= (1000 * TIM_CLK_DIV);
  81
  82         endtime = get_timer_raw() + tmo;
  83
  84         do {
  85                 ulong now = get_timer_raw();
  86                 diff = endtime - now;
  87         } while (diff >= 0);
  88 }
  89
  90 ulong get_tbclk(void)
  91 {
  92         return CONFIG_SYS_HZ;
  93 }