xref: /OK3568_Linux_fs/u-boot/drivers/timer/omap-timer.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun  * TI OMAP timer driver
3*4882a593Smuzhiyun  *
4*4882a593Smuzhiyun  * Copyright (C) 2015, Texas Instruments, Incorporated
5*4882a593Smuzhiyun  *
6*4882a593Smuzhiyun  * SPDX-License-Identifier: GPL-2.0+
7*4882a593Smuzhiyun  */
8*4882a593Smuzhiyun 
9*4882a593Smuzhiyun #include <common.h>
10*4882a593Smuzhiyun #include <dm.h>
11*4882a593Smuzhiyun #include <errno.h>
12*4882a593Smuzhiyun #include <timer.h>
13*4882a593Smuzhiyun #include <asm/io.h>
14*4882a593Smuzhiyun #include <asm/arch/clock.h>
15*4882a593Smuzhiyun 
16*4882a593Smuzhiyun DECLARE_GLOBAL_DATA_PTR;
17*4882a593Smuzhiyun 
18*4882a593Smuzhiyun /* Timer register bits */
19*4882a593Smuzhiyun #define TCLR_START			BIT(0)	/* Start=1 */
20*4882a593Smuzhiyun #define TCLR_AUTO_RELOAD		BIT(1)	/* Auto reload */
21*4882a593Smuzhiyun #define TCLR_PRE_EN			BIT(5)	/* Pre-scaler enable */
22*4882a593Smuzhiyun #define TCLR_PTV_SHIFT			(2)	/* Pre-scaler shift value */
23*4882a593Smuzhiyun 
24*4882a593Smuzhiyun #define TIMER_CLOCK             (V_SCLK / (2 << CONFIG_SYS_PTV))
25*4882a593Smuzhiyun 
26*4882a593Smuzhiyun struct omap_gptimer_regs {
27*4882a593Smuzhiyun 	unsigned int tidr;		/* offset 0x00 */
28*4882a593Smuzhiyun 	unsigned char res1[12];
29*4882a593Smuzhiyun 	unsigned int tiocp_cfg;		/* offset 0x10 */
30*4882a593Smuzhiyun 	unsigned char res2[12];
31*4882a593Smuzhiyun 	unsigned int tier;		/* offset 0x20 */
32*4882a593Smuzhiyun 	unsigned int tistatr;		/* offset 0x24 */
33*4882a593Smuzhiyun 	unsigned int tistat;		/* offset 0x28 */
34*4882a593Smuzhiyun 	unsigned int tisr;		/* offset 0x2c */
35*4882a593Smuzhiyun 	unsigned int tcicr;		/* offset 0x30 */
36*4882a593Smuzhiyun 	unsigned int twer;		/* offset 0x34 */
37*4882a593Smuzhiyun 	unsigned int tclr;		/* offset 0x38 */
38*4882a593Smuzhiyun 	unsigned int tcrr;		/* offset 0x3c */
39*4882a593Smuzhiyun 	unsigned int tldr;		/* offset 0x40 */
40*4882a593Smuzhiyun 	unsigned int ttgr;		/* offset 0x44 */
41*4882a593Smuzhiyun 	unsigned int twpc;		/* offset 0x48 */
42*4882a593Smuzhiyun 	unsigned int tmar;		/* offset 0x4c */
43*4882a593Smuzhiyun 	unsigned int tcar1;		/* offset 0x50 */
44*4882a593Smuzhiyun 	unsigned int tscir;		/* offset 0x54 */
45*4882a593Smuzhiyun 	unsigned int tcar2;		/* offset 0x58 */
46*4882a593Smuzhiyun };
47*4882a593Smuzhiyun 
48*4882a593Smuzhiyun /* Omap Timer Priv */
49*4882a593Smuzhiyun struct omap_timer_priv {
50*4882a593Smuzhiyun 	struct omap_gptimer_regs *regs;
51*4882a593Smuzhiyun };
52*4882a593Smuzhiyun 
omap_timer_get_count(struct udevice * dev,u64 * count)53*4882a593Smuzhiyun static int omap_timer_get_count(struct udevice *dev, u64 *count)
54*4882a593Smuzhiyun {
55*4882a593Smuzhiyun 	struct omap_timer_priv *priv = dev_get_priv(dev);
56*4882a593Smuzhiyun 
57*4882a593Smuzhiyun 	*count = readl(&priv->regs->tcrr);
58*4882a593Smuzhiyun 
59*4882a593Smuzhiyun 	return 0;
60*4882a593Smuzhiyun }
61*4882a593Smuzhiyun 
omap_timer_probe(struct udevice * dev)62*4882a593Smuzhiyun static int omap_timer_probe(struct udevice *dev)
63*4882a593Smuzhiyun {
64*4882a593Smuzhiyun 	struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
65*4882a593Smuzhiyun 	struct omap_timer_priv *priv = dev_get_priv(dev);
66*4882a593Smuzhiyun 
67*4882a593Smuzhiyun 	uc_priv->clock_rate = TIMER_CLOCK;
68*4882a593Smuzhiyun 
69*4882a593Smuzhiyun 	/* start the counter ticking up, reload value on overflow */
70*4882a593Smuzhiyun 	writel(0, &priv->regs->tldr);
71*4882a593Smuzhiyun 	/* enable timer */
72*4882a593Smuzhiyun 	writel((CONFIG_SYS_PTV << 2) | TCLR_PRE_EN | TCLR_AUTO_RELOAD |
73*4882a593Smuzhiyun 	       TCLR_START, &priv->regs->tclr);
74*4882a593Smuzhiyun 
75*4882a593Smuzhiyun 	return 0;
76*4882a593Smuzhiyun }
77*4882a593Smuzhiyun 
omap_timer_ofdata_to_platdata(struct udevice * dev)78*4882a593Smuzhiyun static int omap_timer_ofdata_to_platdata(struct udevice *dev)
79*4882a593Smuzhiyun {
80*4882a593Smuzhiyun 	struct omap_timer_priv *priv = dev_get_priv(dev);
81*4882a593Smuzhiyun 
82*4882a593Smuzhiyun 	priv->regs = map_physmem(devfdt_get_addr(dev),
83*4882a593Smuzhiyun 				 sizeof(struct omap_gptimer_regs), MAP_NOCACHE);
84*4882a593Smuzhiyun 
85*4882a593Smuzhiyun 	return 0;
86*4882a593Smuzhiyun }
87*4882a593Smuzhiyun 
88*4882a593Smuzhiyun 
89*4882a593Smuzhiyun static const struct timer_ops omap_timer_ops = {
90*4882a593Smuzhiyun 	.get_count = omap_timer_get_count,
91*4882a593Smuzhiyun };
92*4882a593Smuzhiyun 
93*4882a593Smuzhiyun static const struct udevice_id omap_timer_ids[] = {
94*4882a593Smuzhiyun 	{ .compatible = "ti,am335x-timer" },
95*4882a593Smuzhiyun 	{ .compatible = "ti,am4372-timer" },
96*4882a593Smuzhiyun 	{ .compatible = "ti,omap5430-timer" },
97*4882a593Smuzhiyun 	{}
98*4882a593Smuzhiyun };
99*4882a593Smuzhiyun 
100*4882a593Smuzhiyun U_BOOT_DRIVER(omap_timer) = {
101*4882a593Smuzhiyun 	.name	= "omap_timer",
102*4882a593Smuzhiyun 	.id	= UCLASS_TIMER,
103*4882a593Smuzhiyun 	.of_match = omap_timer_ids,
104*4882a593Smuzhiyun 	.ofdata_to_platdata = omap_timer_ofdata_to_platdata,
105*4882a593Smuzhiyun 	.priv_auto_alloc_size = sizeof(struct omap_timer_priv),
106*4882a593Smuzhiyun 	.probe = omap_timer_probe,
107*4882a593Smuzhiyun 	.ops	= &omap_timer_ops,
108*4882a593Smuzhiyun 	.flags = DM_FLAG_PRE_RELOC,
109*4882a593Smuzhiyun };
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