2 * Copyright (C) 2015 Thomas Chou <thomas@wytron.com.tw>
4 * SPDX-License-Identifier: GPL-2.0+
10 #include <dm/device-internal.h>
16 DECLARE_GLOBAL_DATA_PTR
;
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.
27 int notrace
timer_get_count(struct udevice
*dev
, u64
*count
)
29 const struct timer_ops
*ops
= device_get_ops(dev
);
34 return ops
->get_count(dev
, count
);
37 unsigned long notrace
timer_get_rate(struct udevice
*dev
)
39 struct timer_dev_priv
*uc_priv
= dev
->uclass_priv
;
41 return uc_priv
->clock_rate
;
44 static int timer_pre_probe(struct udevice
*dev
)
46 #if !CONFIG_IS_ENABLED(OF_PLATDATA)
47 struct timer_dev_priv
*uc_priv
= dev_get_uclass_priv(dev
);
52 err
= clk_get_by_index(dev
, 0, &timer_clk
);
54 ret
= clk_get_rate(&timer_clk
);
55 if (IS_ERR_VALUE(ret
))
57 uc_priv
->clock_rate
= ret
;
60 dev_read_u32_default(dev
, "clock-frequency", 0);
67 static int timer_post_probe(struct udevice
*dev
)
69 struct timer_dev_priv
*uc_priv
= dev_get_uclass_priv(dev
);
71 if (!uc_priv
->clock_rate
)
77 u64
timer_conv_64(u32 count
)
79 /* increment tbh if tbl has rolled over */
80 if (count
< gd
->timebase_l
)
82 gd
->timebase_l
= count
;
83 return ((u64
)gd
->timebase_h
<< 32) | gd
->timebase_l
;
86 int notrace
dm_timer_init(void)
88 struct udevice
*dev
= NULL
;
89 __maybe_unused ofnode node
;
96 * Directly access gd->dm_root to suppress error messages, if the
97 * virtual root driver does not yet exist.
99 if (gd
->dm_root
== NULL
)
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");
106 if (ofnode_valid(node
) &&
107 uclass_get_device_by_ofnode(UCLASS_TIMER
, node
, &dev
)) {
109 * If the timer is not marked to be bound before
110 * relocation, bind it anyway.
112 if (!lists_bind_fdt(dm_root(), node
, &dev
)) {
113 ret
= device_probe(dev
);
121 /* Fall back to the first available timer */
122 ret
= uclass_first_device_err(UCLASS_TIMER
, &dev
);
135 UCLASS_DRIVER(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
),