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