Merge branch '2020-10-22-misc-changes'
[platform/kernel/u-boot.git] / drivers / timer / sti-timer.c
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 <clk.h>
10 #include <timer.h>
11 #include <linux/err.h>
12
13 #include <asm/io.h>
14 #include <asm/arch-armv7/globaltimer.h>
15
16 struct sti_timer_priv {
17         struct globaltimer *global_timer;
18 };
19
20 static u64 sti_timer_get_count(struct udevice *dev)
21 {
22         struct sti_timer_priv *priv = dev_get_priv(dev);
23         struct globaltimer *global_timer = priv->global_timer;
24         u32 low, high;
25         u64 timer;
26         u32 old = readl(&global_timer->cnt_h);
27
28         while (1) {
29                 low = readl(&global_timer->cnt_l);
30                 high = readl(&global_timer->cnt_h);
31                 if (old == high)
32                         break;
33                 else
34                         old = high;
35         }
36         timer = high;
37         return (u64)((timer << 32) | low);
38 }
39
40 static int sti_timer_probe(struct udevice *dev)
41 {
42         struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
43         struct sti_timer_priv *priv = dev_get_priv(dev);
44         struct clk clk;
45         int err;
46         ulong ret;
47
48         /* get arm global timer base address */
49         priv->global_timer = (struct globaltimer *)dev_read_addr_ptr(dev);
50         if (!priv->global_timer)
51                 return -ENOENT;
52
53         err = clk_get_by_index(dev, 0, &clk);
54         if (!err) {
55                 ret = clk_get_rate(&clk);
56                 if (IS_ERR_VALUE(ret))
57                         return ret;
58                 uc_priv->clock_rate = ret;
59         } else {
60                 uc_priv->clock_rate = CONFIG_SYS_HZ_CLOCK;
61         }
62
63         /* init timer */
64         writel(0x01, &priv->global_timer->ctl);
65
66         return 0;
67 }
68
69 static const struct timer_ops sti_timer_ops = {
70         .get_count = sti_timer_get_count,
71 };
72
73 static const struct udevice_id sti_timer_ids[] = {
74         { .compatible = "arm,cortex-a9-global-timer" },
75         {}
76 };
77
78 U_BOOT_DRIVER(sti_timer) = {
79         .name = "sti_timer",
80         .id = UCLASS_TIMER,
81         .of_match = sti_timer_ids,
82         .priv_auto_alloc_size = sizeof(struct sti_timer_priv),
83         .probe = sti_timer_probe,
84         .ops = &sti_timer_ops,
85 };