1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * (C) Copyright 2009 4 * Vipin Kumar, ST Micoelectronics, vipin.kumar (at) st.com. 5 */ 6 7 #include <common.h> 8 #include <asm/io.h> 9 #include <asm/arch/hardware.h> 10 #include <asm/arch/spr_gpt.h> 11 #include <asm/arch/spr_misc.h> 12 13 #define GPT_RESOLUTION (CONFIG_SPEAR_HZ_CLOCK / CONFIG_SPEAR_HZ) 14 #define READ_TIMER() (readl(&gpt_regs_p->count) & GPT_FREE_RUNNING) 15 16 static struct gpt_regs *const gpt_regs_p = 17 (struct gpt_regs *)CONFIG_SPEAR_TIMERBASE; 18 19 static struct misc_regs *const misc_regs_p = 20 (struct misc_regs *)CONFIG_SPEAR_MISCBASE; 21 22 DECLARE_GLOBAL_DATA_PTR; 23 24 #define timestamp gd->arch.tbl 25 #define lastdec gd->arch.lastinc 26 27 int timer_init(void) 28 { 29 u32 synth; 30 31 /* Prescaler setting */ 32 #if defined(CONFIG_SPEAR3XX) 33 writel(MISC_PRSC_CFG, &misc_regs_p->prsc2_clk_cfg); 34 synth = MISC_GPT4SYNTH; 35 #elif defined(CONFIG_SPEAR600) 36 writel(MISC_PRSC_CFG, &misc_regs_p->prsc1_clk_cfg); 37 synth = MISC_GPT3SYNTH; 38 #else 39 # error Incorrect config. Can only be SPEAR{600|300|310|320} 40 #endif 41 42 writel(readl(&misc_regs_p->periph_clk_cfg) | synth, 43 &misc_regs_p->periph_clk_cfg); 44 45 /* disable timers */ 46 writel(GPT_PRESCALER_1 | GPT_MODE_AUTO_RELOAD, &gpt_regs_p->control); 47 48 /* load value for free running */ 49 writel(GPT_FREE_RUNNING, &gpt_regs_p->compare); 50 51 /* auto reload, start timer */ 52 writel(readl(&gpt_regs_p->control) | GPT_ENABLE, &gpt_regs_p->control); 53 54 /* Reset the timer */ 55 lastdec = READ_TIMER(); 56 timestamp = 0; 57 58 return 0; 59 } 60 61 /* 62 * timer without interrupts 63 */ 64 ulong get_timer(ulong base) 65 { 66 return (get_timer_masked() / GPT_RESOLUTION) - base; 67 } 68 69 void __udelay(unsigned long usec) 70 { 71 ulong tmo; 72 ulong start = get_timer_masked(); 73 ulong tenudelcnt = CONFIG_SPEAR_HZ_CLOCK / (1000 * 100); 74 ulong rndoff; 75 76 rndoff = (usec % 10) ? 1 : 0; 77 78 /* tenudelcnt timer tick gives 10 microsecconds delay */ 79 tmo = ((usec / 10) + rndoff) * tenudelcnt; 80 81 while ((ulong) (get_timer_masked() - start) < tmo) 82 ; 83 } 84 85 ulong get_timer_masked(void) 86 { 87 ulong now = READ_TIMER(); 88 89 if (now >= lastdec) { 90 /* normal mode */ 91 timestamp += now - lastdec; 92 } else { 93 /* we have an overflow ... */ 94 timestamp += now + GPT_FREE_RUNNING - lastdec; 95 } 96 lastdec = now; 97 98 return timestamp; 99 } 100 101 void udelay_masked(unsigned long usec) 102 { 103 return udelay(usec); 104 } 105 106 /* 107 * This function is derived from PowerPC code (read timebase as long long). 108 * On ARM it just returns the timer value. 109 */ 110 unsigned long long get_ticks(void) 111 { 112 return get_timer(0); 113 } 114 115 /* 116 * This function is derived from PowerPC code (timebase clock frequency). 117 * On ARM it returns the number of timer ticks per second. 118 */ 119 ulong get_tbclk(void) 120 { 121 return CONFIG_SPEAR_HZ; 122 } 123