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_SPEAR600)
40 writel(MISC_PRSC_CFG, &misc_regs_p->prsc1_clk_cfg);
41 synth = MISC_GPT3SYNTH;
43 # error Incorrect config. Can only be SPEAR{600|300|310|320}
46 writel(readl(&misc_regs_p->periph_clk_cfg) | synth,
47 &misc_regs_p->periph_clk_cfg);
50 writel(GPT_PRESCALER_1 | GPT_MODE_AUTO_RELOAD, &gpt_regs_p->control);
52 /* load value for free running */
53 writel(GPT_FREE_RUNNING, &gpt_regs_p->compare);
55 /* auto reload, start timer */
56 writel(readl(&gpt_regs_p->control) | GPT_ENABLE, &gpt_regs_p->control);
59 lastdec = READ_TIMER();
66 * timer without interrupts
68 ulong get_timer(ulong base)
70 return (get_timer_masked() / GPT_RESOLUTION) - base;
73 void __udelay(unsigned long usec)
76 ulong start = get_timer_masked();
77 ulong tenudelcnt = CONFIG_SPEAR_HZ_CLOCK / (1000 * 100);
80 rndoff = (usec % 10) ? 1 : 0;
82 /* tenudelcnt timer tick gives 10 microsecconds delay */
83 tmo = ((usec / 10) + rndoff) * tenudelcnt;
85 while ((ulong) (get_timer_masked() - start) < tmo)
89 static ulong get_timer_masked(void)
91 ulong now = READ_TIMER();
95 timestamp += now - lastdec;
97 /* we have an overflow ... */
98 timestamp += now + GPT_FREE_RUNNING - lastdec;
106 * This function is derived from PowerPC code (read timebase as long long).
107 * On ARM it just returns the timer value.
109 unsigned long long get_ticks(void)
115 * This function is derived from PowerPC code (timebase clock frequency).
116 * On ARM it returns the number of timer ticks per second.
118 ulong get_tbclk(void)
120 return CONFIG_SPEAR_HZ;