1 // SPDX-License-Identifier: GPL-2.0+
4 * Vipin Kumar, ST Micoelectronics, vipin.kumar@st.com.
11 #include <asm/arch/hardware.h>
12 #include <asm/arch/spr_gpt.h>
13 #include <asm/arch/spr_misc.h>
14 #include <asm/ptrace.h>
16 #define GPT_RESOLUTION (CONFIG_SPEAR_HZ_CLOCK / CONFIG_SPEAR_HZ)
17 #define READ_TIMER() (readl(&gpt_regs_p->count) & GPT_FREE_RUNNING)
19 static struct gpt_regs *const gpt_regs_p =
20 (struct gpt_regs *)CONFIG_SPEAR_TIMERBASE;
22 static struct misc_regs *const misc_regs_p =
23 (struct misc_regs *)CONFIG_SPEAR_MISCBASE;
25 DECLARE_GLOBAL_DATA_PTR;
27 static ulong get_timer_masked(void);
29 #define timestamp gd->arch.tbl
30 #define lastdec gd->arch.lastinc
36 /* Prescaler setting */
37 #if defined(CONFIG_SPEAR3XX)
38 writel(MISC_PRSC_CFG, &misc_regs_p->prsc2_clk_cfg);
39 synth = MISC_GPT4SYNTH;
40 #elif defined(CONFIG_SPEAR600)
41 writel(MISC_PRSC_CFG, &misc_regs_p->prsc1_clk_cfg);
42 synth = MISC_GPT3SYNTH;
44 # error Incorrect config. Can only be SPEAR{600|300|310|320}
47 writel(readl(&misc_regs_p->periph_clk_cfg) | synth,
48 &misc_regs_p->periph_clk_cfg);
51 writel(GPT_PRESCALER_1 | GPT_MODE_AUTO_RELOAD, &gpt_regs_p->control);
53 /* load value for free running */
54 writel(GPT_FREE_RUNNING, &gpt_regs_p->compare);
56 /* auto reload, start timer */
57 writel(readl(&gpt_regs_p->control) | GPT_ENABLE, &gpt_regs_p->control);
60 lastdec = READ_TIMER();
67 * timer without interrupts
69 ulong get_timer(ulong base)
71 return (get_timer_masked() / GPT_RESOLUTION) - base;
74 void __udelay(unsigned long usec)
77 ulong start = get_timer_masked();
78 ulong tenudelcnt = CONFIG_SPEAR_HZ_CLOCK / (1000 * 100);
81 rndoff = (usec % 10) ? 1 : 0;
83 /* tenudelcnt timer tick gives 10 microsecconds delay */
84 tmo = ((usec / 10) + rndoff) * tenudelcnt;
86 while ((ulong) (get_timer_masked() - start) < tmo)
90 static ulong get_timer_masked(void)
92 ulong now = READ_TIMER();
96 timestamp += now - lastdec;
98 /* we have an overflow ... */
99 timestamp += now + GPT_FREE_RUNNING - lastdec;
107 * This function is derived from PowerPC code (read timebase as long long).
108 * On ARM it just returns the timer value.
110 unsigned long long get_ticks(void)
116 * This function is derived from PowerPC code (timebase clock frequency).
117 * On ARM it returns the number of timer ticks per second.
119 ulong get_tbclk(void)
121 return CONFIG_SPEAR_HZ;