1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright 2016 Google Inc.
4 */
5
6 #include <common.h>
7 #include <dm.h>
8 #include <errno.h>
9 #include <timer.h>
10 #include <asm/io.h>
11 #include <asm/arch/timer.h>
12 #include <linux/err.h>
13
14 #define AST_TICK_TIMER 1
15 #define AST_TMC_RELOAD_VAL 0xffffffff
16
17 struct ast_timer_priv {
18 struct ast_timer *regs;
19 struct ast_timer_counter *tmc;
20 };
21
ast_get_timer_counter(struct ast_timer * timer,int n)22 static struct ast_timer_counter *ast_get_timer_counter(struct ast_timer *timer,
23 int n)
24 {
25 if (n > 3)
26 return &timer->timers2[n - 4];
27 else
28 return &timer->timers1[n - 1];
29 }
30
ast_timer_probe(struct udevice * dev)31 static int ast_timer_probe(struct udevice *dev)
32 {
33 struct ast_timer_priv *priv = dev_get_priv(dev);
34 struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
35
36 writel(AST_TMC_RELOAD_VAL, &priv->tmc->reload_val);
37
38 /*
39 * Stop the timer. This will also load reload_val into
40 * the status register.
41 */
42 clrbits_le32(&priv->regs->ctrl1,
43 AST_TMC_EN << AST_TMC_CTRL1_SHIFT(AST_TICK_TIMER));
44 /* Start the timer from the fixed 1MHz clock. */
45 setbits_le32(&priv->regs->ctrl1,
46 (AST_TMC_EN | AST_TMC_1MHZ) <<
47 AST_TMC_CTRL1_SHIFT(AST_TICK_TIMER));
48
49 uc_priv->clock_rate = AST_TMC_RATE;
50
51 return 0;
52 }
53
ast_timer_get_count(struct udevice * dev)54 static u64 ast_timer_get_count(struct udevice *dev)
55 {
56 struct ast_timer_priv *priv = dev_get_priv(dev);
57
58 return AST_TMC_RELOAD_VAL - readl(&priv->tmc->status);
59 }
60
ast_timer_of_to_plat(struct udevice * dev)61 static int ast_timer_of_to_plat(struct udevice *dev)
62 {
63 struct ast_timer_priv *priv = dev_get_priv(dev);
64
65 priv->regs = dev_read_addr_ptr(dev);
66 if (!priv->regs)
67 return -EINVAL;
68
69 priv->tmc = ast_get_timer_counter(priv->regs, AST_TICK_TIMER);
70
71 return 0;
72 }
73
74 static const struct timer_ops ast_timer_ops = {
75 .get_count = ast_timer_get_count,
76 };
77
78 static const struct udevice_id ast_timer_ids[] = {
79 { .compatible = "aspeed,ast2500-timer" },
80 { .compatible = "aspeed,ast2400-timer" },
81 { }
82 };
83
84 U_BOOT_DRIVER(ast_timer) = {
85 .name = "ast_timer",
86 .id = UCLASS_TIMER,
87 .of_match = ast_timer_ids,
88 .probe = ast_timer_probe,
89 .priv_auto = sizeof(struct ast_timer_priv),
90 .of_to_plat = ast_timer_of_to_plat,
91 .ops = &ast_timer_ops,
92 };
93