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reset: stm32: adapt driver for stm32mp1
[u-boot] / drivers / timer / timer-uclass.c
1 /*
2  * Copyright (C) 2015 Thomas Chou <thomas@wytron.com.tw>
3  *
4  * SPDX-License-Identifier:     GPL-2.0+
5  */
6
7 #include <common.h>
8 #include <dm.h>
9 #include <dm/lists.h>
10 #include <dm/device-internal.h>
11 #include <dm/root.h>
12 #include <clk.h>
13 #include <errno.h>
14 #include <timer.h>
15
16 DECLARE_GLOBAL_DATA_PTR;
17
18 /*
19  * Implement a timer uclass to work with lib/time.c. The timer is usually
20  * a 32/64 bits free-running up counter. The get_rate() method is used to get
21  * the input clock frequency of the timer. The get_count() method is used
22  * to get the current 64 bits count value. If the hardware is counting down,
23  * the value should be inversed inside the method. There may be no real
24  * tick, and no timer interrupt.
25  */
26
27 int notrace timer_get_count(struct udevice *dev, u64 *count)
28 {
29         const struct timer_ops *ops = device_get_ops(dev);
30
31         if (!ops->get_count)
32                 return -ENOSYS;
33
34         return ops->get_count(dev, count);
35 }
36
37 unsigned long notrace timer_get_rate(struct udevice *dev)
38 {
39         struct timer_dev_priv *uc_priv = dev->uclass_priv;
40
41         return uc_priv->clock_rate;
42 }
43
44 static int timer_pre_probe(struct udevice *dev)
45 {
46 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
47         struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
48         struct clk timer_clk;
49         int err;
50         ulong ret;
51
52         err = clk_get_by_index(dev, 0, &timer_clk);
53         if (!err) {
54                 ret = clk_get_rate(&timer_clk);
55                 if (IS_ERR_VALUE(ret))
56                         return ret;
57                 uc_priv->clock_rate = ret;
58         } else {
59                 uc_priv->clock_rate =
60                         dev_read_u32_default(dev, "clock-frequency", 0);
61         }
62 #endif
63
64         return 0;
65 }
66
67 static int timer_post_probe(struct udevice *dev)
68 {
69         struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
70
71         if (!uc_priv->clock_rate)
72                 return -EINVAL;
73
74         return 0;
75 }
76
77 u64 timer_conv_64(u32 count)
78 {
79         /* increment tbh if tbl has rolled over */
80         if (count < gd->timebase_l)
81                 gd->timebase_h++;
82         gd->timebase_l = count;
83         return ((u64)gd->timebase_h << 32) | gd->timebase_l;
84 }
85
86 int notrace dm_timer_init(void)
87 {
88         struct udevice *dev = NULL;
89         __maybe_unused ofnode node;
90         int ret;
91
92         if (gd->timer)
93                 return 0;
94
95         /*
96          * Directly access gd->dm_root to suppress error messages, if the
97          * virtual root driver does not yet exist.
98          */
99         if (gd->dm_root == NULL)
100                 return -EAGAIN;
101
102 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
103         /* Check for a chosen timer to be used for tick */
104         node = ofnode_get_chosen_node("tick-timer");
105
106         if (ofnode_valid(node) &&
107             uclass_get_device_by_ofnode(UCLASS_TIMER, node, &dev)) {
108                 /*
109                  * If the timer is not marked to be bound before
110                  * relocation, bind it anyway.
111                  */
112                 if (!lists_bind_fdt(dm_root(), node, &dev)) {
113                         ret = device_probe(dev);
114                         if (ret)
115                                 return ret;
116                 }
117         }
118 #endif
119
120         if (!dev) {
121                 /* Fall back to the first available timer */
122                 ret = uclass_first_device_err(UCLASS_TIMER, &dev);
123                 if (ret)
124                         return ret;
125         }
126
127         if (dev) {
128                 gd->timer = dev;
129                 return 0;
130         }
131
132         return -ENODEV;
133 }
134
135 UCLASS_DRIVER(timer) = {
136         .id             = UCLASS_TIMER,
137         .name           = "timer",
138         .pre_probe      = timer_pre_probe,
139         .flags          = DM_UC_FLAG_SEQ_ALIAS,
140         .post_probe     = timer_post_probe,
141         .per_device_auto_alloc_size = sizeof(struct timer_dev_priv),
142 };