xref: /OK3568_Linux_fs/u-boot/drivers/timer/sti-timer.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun  * (C) Copyright 2017 Patrice Chotard <patrice.chotard@st.com>
3*4882a593Smuzhiyun  *
4*4882a593Smuzhiyun  * SPDX-License-Identifier:	GPL-2.0+
5*4882a593Smuzhiyun  */
6*4882a593Smuzhiyun 
7*4882a593Smuzhiyun #include <common.h>
8*4882a593Smuzhiyun #include <dm.h>
9*4882a593Smuzhiyun #include <fdtdec.h>
10*4882a593Smuzhiyun #include <timer.h>
11*4882a593Smuzhiyun 
12*4882a593Smuzhiyun #include <asm/io.h>
13*4882a593Smuzhiyun #include <asm/arch-armv7/globaltimer.h>
14*4882a593Smuzhiyun 
15*4882a593Smuzhiyun DECLARE_GLOBAL_DATA_PTR;
16*4882a593Smuzhiyun 
17*4882a593Smuzhiyun struct sti_timer_priv {
18*4882a593Smuzhiyun 	struct globaltimer *global_timer;
19*4882a593Smuzhiyun };
20*4882a593Smuzhiyun 
sti_timer_get_count(struct udevice * dev,u64 * count)21*4882a593Smuzhiyun static int sti_timer_get_count(struct udevice *dev, u64 *count)
22*4882a593Smuzhiyun {
23*4882a593Smuzhiyun 	struct sti_timer_priv *priv = dev_get_priv(dev);
24*4882a593Smuzhiyun 	struct globaltimer *global_timer = priv->global_timer;
25*4882a593Smuzhiyun 	u32 low, high;
26*4882a593Smuzhiyun 	u64 timer;
27*4882a593Smuzhiyun 	u32 old = readl(&global_timer->cnt_h);
28*4882a593Smuzhiyun 
29*4882a593Smuzhiyun 	while (1) {
30*4882a593Smuzhiyun 		low = readl(&global_timer->cnt_l);
31*4882a593Smuzhiyun 		high = readl(&global_timer->cnt_h);
32*4882a593Smuzhiyun 		if (old == high)
33*4882a593Smuzhiyun 			break;
34*4882a593Smuzhiyun 		else
35*4882a593Smuzhiyun 			old = high;
36*4882a593Smuzhiyun 	}
37*4882a593Smuzhiyun 	timer = high;
38*4882a593Smuzhiyun 	*count = (u64)((timer << 32) | low);
39*4882a593Smuzhiyun 
40*4882a593Smuzhiyun 	return 0;
41*4882a593Smuzhiyun }
42*4882a593Smuzhiyun 
sti_timer_probe(struct udevice * dev)43*4882a593Smuzhiyun static int sti_timer_probe(struct udevice *dev)
44*4882a593Smuzhiyun {
45*4882a593Smuzhiyun 	struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
46*4882a593Smuzhiyun 	struct sti_timer_priv *priv = dev_get_priv(dev);
47*4882a593Smuzhiyun 	fdt_addr_t addr;
48*4882a593Smuzhiyun 
49*4882a593Smuzhiyun 	uc_priv->clock_rate = CONFIG_SYS_HZ_CLOCK;
50*4882a593Smuzhiyun 
51*4882a593Smuzhiyun 	/* get arm global timer base address */
52*4882a593Smuzhiyun 	addr = fdtdec_get_addr(gd->fdt_blob, dev_of_offset(dev), "reg");
53*4882a593Smuzhiyun 	priv->global_timer = (struct globaltimer *)addr;
54*4882a593Smuzhiyun 
55*4882a593Smuzhiyun 	/* init timer */
56*4882a593Smuzhiyun 	writel(0x01, &priv->global_timer->ctl);
57*4882a593Smuzhiyun 
58*4882a593Smuzhiyun 	return 0;
59*4882a593Smuzhiyun }
60*4882a593Smuzhiyun 
61*4882a593Smuzhiyun static const struct timer_ops sti_timer_ops = {
62*4882a593Smuzhiyun 	.get_count = sti_timer_get_count,
63*4882a593Smuzhiyun };
64*4882a593Smuzhiyun 
65*4882a593Smuzhiyun static const struct udevice_id sti_timer_ids[] = {
66*4882a593Smuzhiyun 	{ .compatible = "arm,cortex-a9-global-timer" },
67*4882a593Smuzhiyun 	{}
68*4882a593Smuzhiyun };
69*4882a593Smuzhiyun 
70*4882a593Smuzhiyun U_BOOT_DRIVER(sti_timer) = {
71*4882a593Smuzhiyun 	.name = "sti_timer",
72*4882a593Smuzhiyun 	.id = UCLASS_TIMER,
73*4882a593Smuzhiyun 	.of_match = sti_timer_ids,
74*4882a593Smuzhiyun 	.priv_auto_alloc_size = sizeof(struct sti_timer_priv),
75*4882a593Smuzhiyun 	.probe = sti_timer_probe,
76*4882a593Smuzhiyun 	.ops = &sti_timer_ops,
77*4882a593Smuzhiyun 	.flags = DM_FLAG_PRE_RELOC,
78*4882a593Smuzhiyun };
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