1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright (C) 2015 Thomas Chou <thomas@wytron.com.tw>
6 #define LOG_CATEGORY UCLASS_TIMER
12 #include <asm/global_data.h>
14 #include <dm/device_compat.h>
15 #include <dm/device-internal.h>
20 #include <linux/err.h>
23 DECLARE_GLOBAL_DATA_PTR;
26 * Implement a timer uclass to work with lib/time.c. The timer is usually
27 * a 32/64 bits free-running up counter. The get_rate() method is used to get
28 * the input clock frequency of the timer. The get_count() method is used
29 * to get the current 64 bits count value. If the hardware is counting down,
30 * the value should be inversed inside the method. There may be no real
31 * tick, and no timer interrupt.
34 int notrace timer_get_count(struct udevice *dev, u64 *count)
36 struct timer_ops *ops = timer_get_ops(dev);
41 *count = ops->get_count(dev);
45 unsigned long notrace timer_get_rate(struct udevice *dev)
47 struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
49 return uc_priv->clock_rate;
52 static int timer_pre_probe(struct udevice *dev)
54 if (IS_ENABLED(CONFIG_NEEDS_MANUAL_RELOC) &&
55 (gd->flags & GD_FLG_RELOC)) {
56 struct timer_ops *ops = timer_get_ops(dev);
57 static int reloc_done;
61 MANUAL_RELOC(ops->get_count);
67 if (CONFIG_IS_ENABLED(OF_REAL)) {
68 struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
74 * It is possible that a timer device has a null ofnode
76 if (!dev_has_ofnode(dev))
79 err = clk_get_by_index(dev, 0, &timer_clk);
81 ret = clk_get_rate(&timer_clk);
82 if (IS_ERR_VALUE(ret))
84 uc_priv->clock_rate = ret;
87 dev_read_u32_default(dev, "clock-frequency", 0);
94 static int timer_post_probe(struct udevice *dev)
96 struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
98 if (!uc_priv->clock_rate)
104 #if CONFIG_IS_ENABLED(CPU)
105 int timer_timebase_fallback(struct udevice *dev)
108 struct cpu_plat *cpu_plat;
109 struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
111 /* Did we get our clock rate from the device tree? */
112 if (uc_priv->clock_rate)
115 /* Fall back to timebase-frequency */
116 dev_dbg(dev, "missing clocks or clock-frequency property; falling back on timebase-frequency\n");
117 cpu = cpu_get_current_dev();
121 cpu_plat = dev_get_parent_plat(cpu);
125 uc_priv->clock_rate = cpu_plat->timebase_freq;
130 u64 timer_conv_64(u32 count)
132 /* increment tbh if tbl has rolled over */
133 if (count < gd->timebase_l)
135 gd->timebase_l = count;
136 return ((u64)gd->timebase_h << 32) | gd->timebase_l;
139 int dm_timer_init(void)
141 struct udevice *dev = NULL;
142 __maybe_unused ofnode node;
149 * Directly access gd->dm_root to suppress error messages, if the
150 * virtual root driver does not yet exist.
152 if (gd->dm_root == NULL)
155 if (CONFIG_IS_ENABLED(OF_REAL)) {
156 /* Check for a chosen timer to be used for tick */
157 node = ofnode_get_chosen_node("tick-timer");
159 if (ofnode_valid(node) &&
160 uclass_get_device_by_ofnode(UCLASS_TIMER, node, &dev)) {
162 * If the timer is not marked to be bound before
163 * relocation, bind it anyway.
165 if (!lists_bind_fdt(dm_root(), node, &dev, NULL, false)) {
166 ret = device_probe(dev);
174 /* Fall back to the first available timer */
175 ret = uclass_first_device_err(UCLASS_TIMER, &dev);
188 UCLASS_DRIVER(timer) = {
191 .pre_probe = timer_pre_probe,
192 .flags = DM_UC_FLAG_SEQ_ALIAS,
193 .post_probe = timer_post_probe,
194 .per_device_auto = sizeof(struct timer_dev_priv),