1 // SPDX-License-Identifier: GPL-2.0+
4 * Vipin Kumar, ST Micoelectronics, vipin.kumar@st.com.
10 #include <asm/global_data.h>
12 #include <asm/arch/hardware.h>
13 #include <asm/arch/spr_gpt.h>
14 #include <asm/arch/spr_misc.h>
15 #include <asm/ptrace.h>
16 #include <linux/delay.h>
18 #define GPT_RESOLUTION (CONFIG_SPEAR_HZ_CLOCK / CONFIG_SPEAR_HZ)
19 #define READ_TIMER() (readl(&gpt_regs_p->count) & GPT_FREE_RUNNING)
21 static struct gpt_regs *const gpt_regs_p =
22 (struct gpt_regs *)CONFIG_SPEAR_TIMERBASE;
24 static struct misc_regs *const misc_regs_p =
25 (struct misc_regs *)CONFIG_SPEAR_MISCBASE;
27 DECLARE_GLOBAL_DATA_PTR;
29 static ulong get_timer_masked(void);
31 #define timestamp gd->arch.tbl
32 #define lastdec gd->arch.lastinc
38 /* Prescaler setting */
39 #if defined(CONFIG_SPEAR3XX)
40 writel(MISC_PRSC_CFG, &misc_regs_p->prsc2_clk_cfg);
41 synth = MISC_GPT4SYNTH;
42 #elif defined(CONFIG_SPEAR600)
43 writel(MISC_PRSC_CFG, &misc_regs_p->prsc1_clk_cfg);
44 synth = MISC_GPT3SYNTH;
46 # error Incorrect config. Can only be SPEAR{600|300|310|320}
49 writel(readl(&misc_regs_p->periph_clk_cfg) | synth,
50 &misc_regs_p->periph_clk_cfg);
53 writel(GPT_PRESCALER_1 | GPT_MODE_AUTO_RELOAD, &gpt_regs_p->control);
55 /* load value for free running */
56 writel(GPT_FREE_RUNNING, &gpt_regs_p->compare);
58 /* auto reload, start timer */
59 writel(readl(&gpt_regs_p->control) | GPT_ENABLE, &gpt_regs_p->control);
62 lastdec = READ_TIMER();
69 * timer without interrupts
71 ulong get_timer(ulong base)
73 return (get_timer_masked() / GPT_RESOLUTION) - base;
76 void __udelay(unsigned long usec)
79 ulong start = get_timer_masked();
80 ulong tenudelcnt = CONFIG_SPEAR_HZ_CLOCK / (1000 * 100);
83 rndoff = (usec % 10) ? 1 : 0;
85 /* tenudelcnt timer tick gives 10 microsecconds delay */
86 tmo = ((usec / 10) + rndoff) * tenudelcnt;
88 while ((ulong) (get_timer_masked() - start) < tmo)
92 static ulong get_timer_masked(void)
94 ulong now = READ_TIMER();
98 timestamp += now - lastdec;
100 /* we have an overflow ... */
101 timestamp += now + GPT_FREE_RUNNING - lastdec;
109 * This function is derived from PowerPC code (read timebase as long long).
110 * On ARM it just returns the timer value.
112 unsigned long long get_ticks(void)
118 * This function is derived from PowerPC code (timebase clock frequency).
119 * On ARM it returns the number of timer ticks per second.
121 ulong get_tbclk(void)
123 return CONFIG_SPEAR_HZ;