arch/arm/cpu/armv7/iproc-common/timer.c

   1 /*
   2  * Copyright 2014 Broadcom Corporation.
   3  *
   4  * SPDX-License-Identifier:     GPL-2.0+
   5  */
   6
   7 #include <common.h>
   8 #include <div64.h>
   9 #include <asm/io.h>
  10 #include <asm/iproc-common/timer.h>
  11 #include <asm/iproc-common/sysmap.h>
  12
  13 static inline uint64_t timer_global_read(void)
  14 {
  15         uint64_t cur_tick;
  16         uint32_t count_h;
  17         uint32_t count_l;
  18
  19         do {
  20                 count_h = readl(IPROC_PERIPH_GLB_TIM_REG_BASE +
  21                                 TIMER_GLB_HI_OFFSET);
  22                 count_l = readl(IPROC_PERIPH_GLB_TIM_REG_BASE +
  23                                 TIMER_GLB_LOW_OFFSET);
  24                 cur_tick = readl(IPROC_PERIPH_GLB_TIM_REG_BASE +
  25                                  TIMER_GLB_HI_OFFSET);
  26         } while (cur_tick != count_h);
  27
  28         return (cur_tick << 32) + count_l;
  29 }
  30
  31 void timer_global_init(void)
  32 {
  33         writel(0, IPROC_PERIPH_GLB_TIM_REG_BASE + TIMER_GLB_CTRL_OFFSET);
  34         writel(0, IPROC_PERIPH_GLB_TIM_REG_BASE + TIMER_GLB_LOW_OFFSET);
  35         writel(0, IPROC_PERIPH_GLB_TIM_REG_BASE + TIMER_GLB_HI_OFFSET);
  36         writel(TIMER_GLB_TIM_CTRL_TIM_EN,
  37                IPROC_PERIPH_GLB_TIM_REG_BASE + TIMER_GLB_CTRL_OFFSET);
  38 }
  39
  40 int timer_init(void)
  41 {
  42         timer_global_init();
  43         return 0;
  44 }
  45
  46 unsigned long get_timer(unsigned long base)
  47 {
  48         uint64_t count;
  49         uint64_t ret;
  50         uint64_t tim_clk;
  51         uint64_t periph_clk;
  52
  53         count = timer_global_read();
  54
  55         /* default arm clk is 1GHz, periph_clk=arm_clk/2, tick per msec */
  56         periph_clk = 500000;
  57         tim_clk = lldiv(periph_clk,
  58                         (((readl(IPROC_PERIPH_GLB_TIM_REG_BASE +
  59                                  TIMER_GLB_CTRL_OFFSET) &
  60                         TIMER_GLB_TIM_CTRL_PRESC_MASK) >> 8) + 1));
  61
  62         ret = lldiv(count, (uint32_t)tim_clk);
  63
  64         /* returns msec */
  65         return ret - base;
  66 }
  67
  68 void __udelay(unsigned long usec)
  69 {
  70         uint64_t cur_tick, end_tick;
  71         uint64_t tim_clk;
  72         uint64_t periph_clk;
  73
  74         /* default arm clk is 1GHz, periph_clk=arm_clk/2, tick per usec */
  75         periph_clk = 500;
  76
  77         tim_clk = lldiv(periph_clk,
  78                         (((readl(IPROC_PERIPH_GLB_TIM_REG_BASE +
  79                                  TIMER_GLB_CTRL_OFFSET) &
  80                         TIMER_GLB_TIM_CTRL_PRESC_MASK) >> 8) + 1));
  81
  82         cur_tick = timer_global_read();
  83
  84         end_tick = tim_clk;
  85         end_tick *= usec;
  86         end_tick += cur_tick;
  87
  88         do {
  89                 cur_tick = timer_global_read();
  90
  91         } while (cur_tick < end_tick);
  92 }
  93
  94 void timer_systick_init(uint32_t tick_ms)
  95 {
  96         /* Disable timer and clear interrupt status*/
  97         writel(0, IPROC_PERIPH_PVT_TIM_REG_BASE + TIMER_PVT_CTRL_OFFSET);
  98         writel(TIMER_PVT_TIM_INT_STATUS_SET,
  99                IPROC_PERIPH_PVT_TIM_REG_BASE + TIMER_PVT_STATUS_OFFSET);
 100         writel((PLL_AXI_CLK/1000) * tick_ms,
 101                IPROC_PERIPH_PVT_TIM_REG_BASE + TIMER_PVT_LOAD_OFFSET);
 102         writel(TIMER_PVT_TIM_CTRL_INT_EN |
 103                TIMER_PVT_TIM_CTRL_AUTO_RELD |
 104                TIMER_PVT_TIM_CTRL_TIM_EN,
 105                IPROC_PERIPH_PVT_TIM_REG_BASE + TIMER_PVT_CTRL_OFFSET);
 106 }
 107
 108 void timer_systick_isr(void *data)
 109 {
 110         writel(TIMER_PVT_TIM_INT_STATUS_SET,
 111                IPROC_PERIPH_PVT_TIM_REG_BASE + TIMER_PVT_STATUS_OFFSET);
 112 }
 113
 114 /*
 115  * This function is derived from PowerPC code (read timebase as long long).
 116  * On ARM it just returns the timer value in msec.
 117  */
 118 unsigned long long get_ticks(void)
 119 {
 120         return get_timer(0);
 121 }
 122
 123 /*
 124  * This is used in conjuction with get_ticks, which returns msec as ticks.
 125  * Here we just return ticks/sec = msec/sec = 1000
 126  */
 127 ulong get_tbclk(void)
 128 {
 129         return 1000;
 130 }