1 /* 2 * (C) Copyright 2009 3 * Vipin Kumar, ST Micoelectronics, vipin.kumar@st.com. 4 * 5 * SPDX-License-Identifier: GPL-2.0+ 6 */ 7 8 #include <common.h> 9 #include <asm/io.h> 10 #include <asm/arch/hardware.h> 11 #include <asm/arch/spr_gpt.h> 12 #include <asm/arch/spr_misc.h> 13 14 #define GPT_RESOLUTION (CONFIG_SPEAR_HZ_CLOCK / CONFIG_SPEAR_HZ) 15 #define READ_TIMER() (readl(&gpt_regs_p->count) & GPT_FREE_RUNNING) 16 17 static struct gpt_regs *const gpt_regs_p = 18 (struct gpt_regs *)CONFIG_SPEAR_TIMERBASE; 19 20 static struct misc_regs *const misc_regs_p = 21 (struct misc_regs *)CONFIG_SPEAR_MISCBASE; 22 23 DECLARE_GLOBAL_DATA_PTR; 24 25 #define timestamp gd->arch.tbl 26 #define lastdec gd->arch.lastinc 27 28 int timer_init(void) 29 { 30 u32 synth; 31 32 /* Prescaler setting */ 33 #if defined(CONFIG_SPEAR3XX) 34 writel(MISC_PRSC_CFG, &misc_regs_p->prsc2_clk_cfg); 35 synth = MISC_GPT4SYNTH; 36 #elif defined(CONFIG_SPEAR600) 37 writel(MISC_PRSC_CFG, &misc_regs_p->prsc1_clk_cfg); 38 synth = MISC_GPT3SYNTH; 39 #else 40 # error Incorrect config. Can only be SPEAR{600|300|310|320} 41 #endif 42 43 writel(readl(&misc_regs_p->periph_clk_cfg) | synth, 44 &misc_regs_p->periph_clk_cfg); 45 46 /* disable timers */ 47 writel(GPT_PRESCALER_1 | GPT_MODE_AUTO_RELOAD, &gpt_regs_p->control); 48 49 /* load value for free running */ 50 writel(GPT_FREE_RUNNING, &gpt_regs_p->compare); 51 52 /* auto reload, start timer */ 53 writel(readl(&gpt_regs_p->control) | GPT_ENABLE, &gpt_regs_p->control); 54 55 /* Reset the timer */ 56 lastdec = READ_TIMER(); 57 timestamp = 0; 58 59 return 0; 60 } 61 62 /* 63 * timer without interrupts 64 */ 65 ulong get_timer(ulong base) 66 { 67 return (get_timer_masked() / GPT_RESOLUTION) - base; 68 } 69 70 void __udelay(unsigned long usec) 71 { 72 ulong tmo; 73 ulong start = get_timer_masked(); 74 ulong tenudelcnt = CONFIG_SPEAR_HZ_CLOCK / (1000 * 100); 75 ulong rndoff; 76 77 rndoff = (usec % 10) ? 1 : 0; 78 79 /* tenudelcnt timer tick gives 10 microsecconds delay */ 80 tmo = ((usec / 10) + rndoff) * tenudelcnt; 81 82 while ((ulong) (get_timer_masked() - start) < tmo) 83 ; 84 } 85 86 ulong get_timer_masked(void) 87 { 88 ulong now = READ_TIMER(); 89 90 if (now >= lastdec) { 91 /* normal mode */ 92 timestamp += now - lastdec; 93 } else { 94 /* we have an overflow ... */ 95 timestamp += now + GPT_FREE_RUNNING - lastdec; 96 } 97 lastdec = now; 98 99 return timestamp; 100 } 101 102 void udelay_masked(unsigned long usec) 103 { 104 return udelay(usec); 105 } 106 107 /* 108 * This function is derived from PowerPC code (read timebase as long long). 109 * On ARM it just returns the timer value. 110 */ 111 unsigned long long get_ticks(void) 112 { 113 return get_timer(0); 114 } 115 116 /* 117 * This function is derived from PowerPC code (timebase clock frequency). 118 * On ARM it returns the number of timer ticks per second. 119 */ 120 ulong get_tbclk(void) 121 { 122 return CONFIG_SPEAR_HZ; 123 } 124