xref: /OK3568_Linux_fs/u-boot/drivers/timer/ast_timer.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun  * Copyright 2016 Google Inc.
3*4882a593Smuzhiyun  *
4*4882a593Smuzhiyun  * SPDX-License-Identifier:	GPL-2.0+
5*4882a593Smuzhiyun  */
6*4882a593Smuzhiyun 
7*4882a593Smuzhiyun #include <common.h>
8*4882a593Smuzhiyun #include <dm.h>
9*4882a593Smuzhiyun #include <errno.h>
10*4882a593Smuzhiyun #include <timer.h>
11*4882a593Smuzhiyun #include <asm/io.h>
12*4882a593Smuzhiyun #include <asm/arch/timer.h>
13*4882a593Smuzhiyun 
14*4882a593Smuzhiyun DECLARE_GLOBAL_DATA_PTR;
15*4882a593Smuzhiyun 
16*4882a593Smuzhiyun #define AST_TICK_TIMER  1
17*4882a593Smuzhiyun #define AST_TMC_RELOAD_VAL  0xffffffff
18*4882a593Smuzhiyun 
19*4882a593Smuzhiyun struct ast_timer_priv {
20*4882a593Smuzhiyun 	struct ast_timer *regs;
21*4882a593Smuzhiyun 	struct ast_timer_counter *tmc;
22*4882a593Smuzhiyun };
23*4882a593Smuzhiyun 
ast_get_timer_counter(struct ast_timer * timer,int n)24*4882a593Smuzhiyun static struct ast_timer_counter *ast_get_timer_counter(struct ast_timer *timer,
25*4882a593Smuzhiyun 						       int n)
26*4882a593Smuzhiyun {
27*4882a593Smuzhiyun 	if (n > 3)
28*4882a593Smuzhiyun 		return &timer->timers2[n - 4];
29*4882a593Smuzhiyun 	else
30*4882a593Smuzhiyun 		return &timer->timers1[n - 1];
31*4882a593Smuzhiyun }
32*4882a593Smuzhiyun 
ast_timer_probe(struct udevice * dev)33*4882a593Smuzhiyun static int ast_timer_probe(struct udevice *dev)
34*4882a593Smuzhiyun {
35*4882a593Smuzhiyun 	struct ast_timer_priv *priv = dev_get_priv(dev);
36*4882a593Smuzhiyun 	struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
37*4882a593Smuzhiyun 
38*4882a593Smuzhiyun 	writel(AST_TMC_RELOAD_VAL, &priv->tmc->reload_val);
39*4882a593Smuzhiyun 
40*4882a593Smuzhiyun 	/*
41*4882a593Smuzhiyun 	 * Stop the timer. This will also load reload_val into
42*4882a593Smuzhiyun 	 * the status register.
43*4882a593Smuzhiyun 	 */
44*4882a593Smuzhiyun 	clrbits_le32(&priv->regs->ctrl1,
45*4882a593Smuzhiyun 		     AST_TMC_EN << AST_TMC_CTRL1_SHIFT(AST_TICK_TIMER));
46*4882a593Smuzhiyun 	/* Start the timer from the fixed 1MHz clock. */
47*4882a593Smuzhiyun 	setbits_le32(&priv->regs->ctrl1,
48*4882a593Smuzhiyun 		     (AST_TMC_EN | AST_TMC_1MHZ) <<
49*4882a593Smuzhiyun 		     AST_TMC_CTRL1_SHIFT(AST_TICK_TIMER));
50*4882a593Smuzhiyun 
51*4882a593Smuzhiyun 	uc_priv->clock_rate = AST_TMC_RATE;
52*4882a593Smuzhiyun 
53*4882a593Smuzhiyun 	return 0;
54*4882a593Smuzhiyun }
55*4882a593Smuzhiyun 
ast_timer_get_count(struct udevice * dev,u64 * count)56*4882a593Smuzhiyun static int ast_timer_get_count(struct udevice *dev, u64 *count)
57*4882a593Smuzhiyun {
58*4882a593Smuzhiyun 	struct ast_timer_priv *priv = dev_get_priv(dev);
59*4882a593Smuzhiyun 
60*4882a593Smuzhiyun 	*count = AST_TMC_RELOAD_VAL - readl(&priv->tmc->status);
61*4882a593Smuzhiyun 
62*4882a593Smuzhiyun 	return 0;
63*4882a593Smuzhiyun }
64*4882a593Smuzhiyun 
ast_timer_ofdata_to_platdata(struct udevice * dev)65*4882a593Smuzhiyun static int ast_timer_ofdata_to_platdata(struct udevice *dev)
66*4882a593Smuzhiyun {
67*4882a593Smuzhiyun 	struct ast_timer_priv *priv = dev_get_priv(dev);
68*4882a593Smuzhiyun 
69*4882a593Smuzhiyun 	priv->regs = devfdt_get_addr_ptr(dev);
70*4882a593Smuzhiyun 	if (IS_ERR(priv->regs))
71*4882a593Smuzhiyun 		return PTR_ERR(priv->regs);
72*4882a593Smuzhiyun 
73*4882a593Smuzhiyun 	priv->tmc = ast_get_timer_counter(priv->regs, AST_TICK_TIMER);
74*4882a593Smuzhiyun 
75*4882a593Smuzhiyun 	return 0;
76*4882a593Smuzhiyun }
77*4882a593Smuzhiyun 
78*4882a593Smuzhiyun static const struct timer_ops ast_timer_ops = {
79*4882a593Smuzhiyun 	.get_count = ast_timer_get_count,
80*4882a593Smuzhiyun };
81*4882a593Smuzhiyun 
82*4882a593Smuzhiyun static const struct udevice_id ast_timer_ids[] = {
83*4882a593Smuzhiyun 	{ .compatible = "aspeed,ast2500-timer" },
84*4882a593Smuzhiyun 	{ .compatible = "aspeed,ast2400-timer" },
85*4882a593Smuzhiyun 	{ }
86*4882a593Smuzhiyun };
87*4882a593Smuzhiyun 
88*4882a593Smuzhiyun U_BOOT_DRIVER(ast_timer) = {
89*4882a593Smuzhiyun 	.name = "ast_timer",
90*4882a593Smuzhiyun 	.id = UCLASS_TIMER,
91*4882a593Smuzhiyun 	.of_match = ast_timer_ids,
92*4882a593Smuzhiyun 	.probe = ast_timer_probe,
93*4882a593Smuzhiyun 	.priv_auto_alloc_size = sizeof(struct ast_timer_priv),
94*4882a593Smuzhiyun 	.ofdata_to_platdata = ast_timer_ofdata_to_platdata,
95*4882a593Smuzhiyun 	.ops = &ast_timer_ops,
96*4882a593Smuzhiyun 	.flags = DM_FLAG_PRE_RELOC,
97*4882a593Smuzhiyun };
98