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

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright 2014 Broadcom Corporation.
   4  */
   5
   6 #include <common.h>
   7 #include <div64.h>
   8 #include <init.h>
   9 #include <time.h>
  10 #include <asm/io.h>
  11 #include <asm/iproc-common/timer.h>
  12 #include <asm/iproc-common/sysmap.h>
  13 #include <linux/delay.h>
  14
  15 static inline uint64_t timer_global_read(void)
  16 {
  17         uint64_t cur_tick;
  18         uint32_t count_h;
  19         uint32_t count_l;
  20
  21         do {
  22                 count_h = readl(IPROC_PERIPH_GLB_TIM_REG_BASE +
  23                                 TIMER_GLB_HI_OFFSET);
  24                 count_l = readl(IPROC_PERIPH_GLB_TIM_REG_BASE +
  25                                 TIMER_GLB_LOW_OFFSET);
  26                 cur_tick = readl(IPROC_PERIPH_GLB_TIM_REG_BASE +
  27                                  TIMER_GLB_HI_OFFSET);
  28         } while (cur_tick != count_h);
  29
  30         return (cur_tick << 32) + count_l;
  31 }
  32
  33 void timer_global_init(void)
  34 {
  35         writel(0, IPROC_PERIPH_GLB_TIM_REG_BASE + TIMER_GLB_CTRL_OFFSET);
  36         writel(0, IPROC_PERIPH_GLB_TIM_REG_BASE + TIMER_GLB_LOW_OFFSET);
  37         writel(0, IPROC_PERIPH_GLB_TIM_REG_BASE + TIMER_GLB_HI_OFFSET);
  38         writel(TIMER_GLB_TIM_CTRL_TIM_EN,
  39                IPROC_PERIPH_GLB_TIM_REG_BASE + TIMER_GLB_CTRL_OFFSET);
  40 }
  41
  42 int timer_init(void)
  43 {
  44         timer_global_init();
  45         return 0;
  46 }
  47
  48 unsigned long get_timer(unsigned long base)
  49 {
  50         uint64_t count;
  51         uint64_t ret;
  52         uint64_t tim_clk;
  53         uint64_t periph_clk;
  54
  55         count = timer_global_read();
  56
  57         /* default arm clk is 1GHz, periph_clk=arm_clk/2, tick per msec */
  58         periph_clk = 500000;
  59         tim_clk = lldiv(periph_clk,
  60                         (((readl(IPROC_PERIPH_GLB_TIM_REG_BASE +
  61                                  TIMER_GLB_CTRL_OFFSET) &
  62                         TIMER_GLB_TIM_CTRL_PRESC_MASK) >> 8) + 1));
  63
  64         ret = lldiv(count, (uint32_t)tim_clk);
  65
  66         /* returns msec */
  67         return ret - base;
  68 }
  69
  70 void __udelay(unsigned long usec)
  71 {
  72         uint64_t cur_tick, end_tick;
  73         uint64_t tim_clk;
  74         uint64_t periph_clk;
  75
  76         /* default arm clk is 1GHz, periph_clk=arm_clk/2, tick per usec */
  77         periph_clk = 500;
  78
  79         tim_clk = lldiv(periph_clk,
  80                         (((readl(IPROC_PERIPH_GLB_TIM_REG_BASE +
  81                                  TIMER_GLB_CTRL_OFFSET) &
  82                         TIMER_GLB_TIM_CTRL_PRESC_MASK) >> 8) + 1));
  83
  84         cur_tick = timer_global_read();
  85
  86         end_tick = tim_clk;
  87         end_tick *= usec;
  88         end_tick += cur_tick;
  89
  90         do {
  91                 cur_tick = timer_global_read();
  92
  93         } while (cur_tick < end_tick);
  94 }
  95
  96 void timer_systick_init(uint32_t tick_ms)
  97 {
  98         /* Disable timer and clear interrupt status*/
  99         writel(0, IPROC_PERIPH_PVT_TIM_REG_BASE + TIMER_PVT_CTRL_OFFSET);
 100         writel(TIMER_PVT_TIM_INT_STATUS_SET,
 101                IPROC_PERIPH_PVT_TIM_REG_BASE + TIMER_PVT_STATUS_OFFSET);
 102         writel((PLL_AXI_CLK/1000) * tick_ms,
 103                IPROC_PERIPH_PVT_TIM_REG_BASE + TIMER_PVT_LOAD_OFFSET);
 104         writel(TIMER_PVT_TIM_CTRL_INT_EN |
 105                TIMER_PVT_TIM_CTRL_AUTO_RELD |
 106                TIMER_PVT_TIM_CTRL_TIM_EN,
 107                IPROC_PERIPH_PVT_TIM_REG_BASE + TIMER_PVT_CTRL_OFFSET);
 108 }
 109
 110 void timer_systick_isr(void *data)
 111 {
 112         writel(TIMER_PVT_TIM_INT_STATUS_SET,
 113                IPROC_PERIPH_PVT_TIM_REG_BASE + TIMER_PVT_STATUS_OFFSET);
 114 }
 115
 116 /*
 117  * This function is derived from PowerPC code (read timebase as long long).
 118  * On ARM it just returns the timer value in msec.
 119  */
 120 unsigned long long get_ticks(void)
 121 {
 122         return get_timer(0);
 123 }
 124
 125 /*
 126  * This is used in conjuction with get_ticks, which returns msec as ticks.
 127  * Here we just return ticks/sec = msec/sec = 1000
 128  */
 129 ulong get_tbclk(void)
 130 {
 131         return 1000;
 132 }