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