xref: /OK3568_Linux_fs/u-boot/arch/arm/cpu/armv7/stv0991/timer.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun  * (C) Copyright 2014
3*4882a593Smuzhiyun  * Vikas Manocha, ST Micoelectronics, vikas.manocha@st.com.
4*4882a593Smuzhiyun  *
5*4882a593Smuzhiyun  * SPDX-License-Identifier:	GPL-2.0+
6*4882a593Smuzhiyun  */
7*4882a593Smuzhiyun 
8*4882a593Smuzhiyun #include <common.h>
9*4882a593Smuzhiyun #include <asm/io.h>
10*4882a593Smuzhiyun #include <asm/arch-stv0991/hardware.h>
11*4882a593Smuzhiyun #include <asm/arch-stv0991/stv0991_cgu.h>
12*4882a593Smuzhiyun #include <asm/arch-stv0991/stv0991_gpt.h>
13*4882a593Smuzhiyun 
14*4882a593Smuzhiyun static struct stv0991_cgu_regs *const stv0991_cgu_regs = \
15*4882a593Smuzhiyun 				(struct stv0991_cgu_regs *) (CGU_BASE_ADDR);
16*4882a593Smuzhiyun 
17*4882a593Smuzhiyun #define READ_TIMER()	(readl(&gpt1_regs_ptr->cnt) & GPT_FREE_RUNNING)
18*4882a593Smuzhiyun #define GPT_RESOLUTION	(CONFIG_STV0991_HZ_CLOCK / CONFIG_STV0991_HZ)
19*4882a593Smuzhiyun 
20*4882a593Smuzhiyun DECLARE_GLOBAL_DATA_PTR;
21*4882a593Smuzhiyun 
22*4882a593Smuzhiyun #define timestamp gd->arch.tbl
23*4882a593Smuzhiyun #define lastdec gd->arch.lastinc
24*4882a593Smuzhiyun 
timer_init(void)25*4882a593Smuzhiyun int timer_init(void)
26*4882a593Smuzhiyun {
27*4882a593Smuzhiyun 	/* Timer1 clock configuration */
28*4882a593Smuzhiyun 	writel(TIMER1_CLK_CFG, &stv0991_cgu_regs->tim_freq);
29*4882a593Smuzhiyun 	writel(readl(&stv0991_cgu_regs->cgu_enable_2) |
30*4882a593Smuzhiyun 			TIMER1_CLK_EN, &stv0991_cgu_regs->cgu_enable_2);
31*4882a593Smuzhiyun 
32*4882a593Smuzhiyun 	/* Stop the timer */
33*4882a593Smuzhiyun 	writel(readl(&gpt1_regs_ptr->cr1) & ~GPT_CR1_CEN, &gpt1_regs_ptr->cr1);
34*4882a593Smuzhiyun 	writel(GPT_PRESCALER_128, &gpt1_regs_ptr->psc);
35*4882a593Smuzhiyun 	/* Configure timer for auto-reload */
36*4882a593Smuzhiyun 	writel(readl(&gpt1_regs_ptr->cr1) | GPT_MODE_AUTO_RELOAD,
37*4882a593Smuzhiyun 			&gpt1_regs_ptr->cr1);
38*4882a593Smuzhiyun 
39*4882a593Smuzhiyun 	/* load value for free running */
40*4882a593Smuzhiyun 	writel(GPT_FREE_RUNNING, &gpt1_regs_ptr->arr);
41*4882a593Smuzhiyun 
42*4882a593Smuzhiyun 	/* start timer */
43*4882a593Smuzhiyun 	writel(readl(&gpt1_regs_ptr->cr1) | GPT_CR1_CEN,
44*4882a593Smuzhiyun 			&gpt1_regs_ptr->cr1);
45*4882a593Smuzhiyun 
46*4882a593Smuzhiyun 	/* Reset the timer */
47*4882a593Smuzhiyun 	lastdec = READ_TIMER();
48*4882a593Smuzhiyun 	timestamp = 0;
49*4882a593Smuzhiyun 
50*4882a593Smuzhiyun 	return 0;
51*4882a593Smuzhiyun }
52*4882a593Smuzhiyun 
53*4882a593Smuzhiyun /*
54*4882a593Smuzhiyun  * timer without interrupts
55*4882a593Smuzhiyun  */
get_timer(ulong base)56*4882a593Smuzhiyun ulong get_timer(ulong base)
57*4882a593Smuzhiyun {
58*4882a593Smuzhiyun 	return (get_timer_masked() / GPT_RESOLUTION) - base;
59*4882a593Smuzhiyun }
60*4882a593Smuzhiyun 
__udelay(unsigned long usec)61*4882a593Smuzhiyun void __udelay(unsigned long usec)
62*4882a593Smuzhiyun {
63*4882a593Smuzhiyun 	ulong tmo;
64*4882a593Smuzhiyun 	ulong start = get_timer_masked();
65*4882a593Smuzhiyun 	ulong tenudelcnt = CONFIG_STV0991_HZ_CLOCK / (1000 * 100);
66*4882a593Smuzhiyun 	ulong rndoff;
67*4882a593Smuzhiyun 
68*4882a593Smuzhiyun 	rndoff = (usec % 10) ? 1 : 0;
69*4882a593Smuzhiyun 
70*4882a593Smuzhiyun 	/* tenudelcnt timer tick gives 10 microsecconds delay */
71*4882a593Smuzhiyun 	tmo = ((usec / 10) + rndoff) * tenudelcnt;
72*4882a593Smuzhiyun 
73*4882a593Smuzhiyun 	while ((ulong) (get_timer_masked() - start) < tmo)
74*4882a593Smuzhiyun 		;
75*4882a593Smuzhiyun }
76*4882a593Smuzhiyun 
get_timer_masked(void)77*4882a593Smuzhiyun ulong get_timer_masked(void)
78*4882a593Smuzhiyun {
79*4882a593Smuzhiyun 	ulong now = READ_TIMER();
80*4882a593Smuzhiyun 
81*4882a593Smuzhiyun 	if (now >= lastdec) {
82*4882a593Smuzhiyun 		/* normal mode */
83*4882a593Smuzhiyun 		timestamp += now - lastdec;
84*4882a593Smuzhiyun 	} else {
85*4882a593Smuzhiyun 		/* we have an overflow ... */
86*4882a593Smuzhiyun 		timestamp += now + GPT_FREE_RUNNING - lastdec;
87*4882a593Smuzhiyun 	}
88*4882a593Smuzhiyun 	lastdec = now;
89*4882a593Smuzhiyun 
90*4882a593Smuzhiyun 	return timestamp;
91*4882a593Smuzhiyun }
92*4882a593Smuzhiyun 
udelay_masked(unsigned long usec)93*4882a593Smuzhiyun void udelay_masked(unsigned long usec)
94*4882a593Smuzhiyun {
95*4882a593Smuzhiyun 	return udelay(usec);
96*4882a593Smuzhiyun }
97*4882a593Smuzhiyun 
98*4882a593Smuzhiyun /*
99*4882a593Smuzhiyun  * This function is derived from PowerPC code (read timebase as long long).
100*4882a593Smuzhiyun  * On ARM it just returns the timer value.
101*4882a593Smuzhiyun  */
get_ticks(void)102*4882a593Smuzhiyun unsigned long long get_ticks(void)
103*4882a593Smuzhiyun {
104*4882a593Smuzhiyun 	return get_timer(0);
105*4882a593Smuzhiyun }
106*4882a593Smuzhiyun 
107*4882a593Smuzhiyun /*
108*4882a593Smuzhiyun  * This function is derived from PowerPC code (timebase clock frequency).
109*4882a593Smuzhiyun  * On ARM it returns the number of timer ticks per second.
110*4882a593Smuzhiyun  */
get_tbclk(void)111*4882a593Smuzhiyun ulong get_tbclk(void)
112*4882a593Smuzhiyun {
113*4882a593Smuzhiyun 	return CONFIG_STV0991_HZ;
114*4882a593Smuzhiyun }
115