xref: /openbmc/u-boot/drivers/timer/sti-timer.c (revision 1d6edcbf)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
4  * Author(s): Patrice Chotard, <patrice.chotard@st.com> for STMicroelectronics.
5  */
6 
7 #include <common.h>
8 #include <dm.h>
9 #include <fdtdec.h>
10 #include <timer.h>
11 
12 #include <asm/io.h>
13 #include <asm/arch-armv7/globaltimer.h>
14 
15 DECLARE_GLOBAL_DATA_PTR;
16 
17 struct sti_timer_priv {
18 	struct globaltimer *global_timer;
19 };
20 
sti_timer_get_count(struct udevice * dev,u64 * count)21 static int sti_timer_get_count(struct udevice *dev, u64 *count)
22 {
23 	struct sti_timer_priv *priv = dev_get_priv(dev);
24 	struct globaltimer *global_timer = priv->global_timer;
25 	u32 low, high;
26 	u64 timer;
27 	u32 old = readl(&global_timer->cnt_h);
28 
29 	while (1) {
30 		low = readl(&global_timer->cnt_l);
31 		high = readl(&global_timer->cnt_h);
32 		if (old == high)
33 			break;
34 		else
35 			old = high;
36 	}
37 	timer = high;
38 	*count = (u64)((timer << 32) | low);
39 
40 	return 0;
41 }
42 
sti_timer_probe(struct udevice * dev)43 static int sti_timer_probe(struct udevice *dev)
44 {
45 	struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
46 	struct sti_timer_priv *priv = dev_get_priv(dev);
47 	fdt_addr_t addr;
48 
49 	uc_priv->clock_rate = CONFIG_SYS_HZ_CLOCK;
50 
51 	/* get arm global timer base address */
52 	addr = fdtdec_get_addr(gd->fdt_blob, dev_of_offset(dev), "reg");
53 	priv->global_timer = (struct globaltimer *)addr;
54 
55 	/* init timer */
56 	writel(0x01, &priv->global_timer->ctl);
57 
58 	return 0;
59 }
60 
61 static const struct timer_ops sti_timer_ops = {
62 	.get_count = sti_timer_get_count,
63 };
64 
65 static const struct udevice_id sti_timer_ids[] = {
66 	{ .compatible = "arm,cortex-a9-global-timer" },
67 	{}
68 };
69 
70 U_BOOT_DRIVER(sti_timer) = {
71 	.name = "sti_timer",
72 	.id = UCLASS_TIMER,
73 	.of_match = sti_timer_ids,
74 	.priv_auto_alloc_size = sizeof(struct sti_timer_priv),
75 	.probe = sti_timer_probe,
76 	.ops = &sti_timer_ops,
77 };
78