1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * (C) Copyright 2000-2002
4 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 *
6 * (C) Copyright 2004, Psyent Corporation <www.psyent.com>
7 * Scott McNutt <smcnutt@psyent.com>
8 */
9
10 #include <common.h>
11 #include <dm.h>
12 #include <errno.h>
13 #include <timer.h>
14 #include <asm/io.h>
15
16 /* control register */
17 #define ALTERA_TIMER_CONT BIT(1) /* Continuous mode */
18 #define ALTERA_TIMER_START BIT(2) /* Start timer */
19 #define ALTERA_TIMER_STOP BIT(3) /* Stop timer */
20
21 struct altera_timer_regs {
22 u32 status; /* Timer status reg */
23 u32 control; /* Timer control reg */
24 u32 periodl; /* Timeout period low */
25 u32 periodh; /* Timeout period high */
26 u32 snapl; /* Snapshot low */
27 u32 snaph; /* Snapshot high */
28 };
29
30 struct altera_timer_platdata {
31 struct altera_timer_regs *regs;
32 };
33
altera_timer_get_count(struct udevice * dev,u64 * count)34 static int altera_timer_get_count(struct udevice *dev, u64 *count)
35 {
36 struct altera_timer_platdata *plat = dev->platdata;
37 struct altera_timer_regs *const regs = plat->regs;
38 u32 val;
39
40 /* Trigger update */
41 writel(0x0, ®s->snapl);
42
43 /* Read timer value */
44 val = readl(®s->snapl) & 0xffff;
45 val |= (readl(®s->snaph) & 0xffff) << 16;
46 *count = timer_conv_64(~val);
47
48 return 0;
49 }
50
altera_timer_probe(struct udevice * dev)51 static int altera_timer_probe(struct udevice *dev)
52 {
53 struct altera_timer_platdata *plat = dev->platdata;
54 struct altera_timer_regs *const regs = plat->regs;
55
56 writel(0, ®s->status);
57 writel(0, ®s->control);
58 writel(ALTERA_TIMER_STOP, ®s->control);
59
60 writel(0xffff, ®s->periodl);
61 writel(0xffff, ®s->periodh);
62 writel(ALTERA_TIMER_CONT | ALTERA_TIMER_START, ®s->control);
63
64 return 0;
65 }
66
altera_timer_ofdata_to_platdata(struct udevice * dev)67 static int altera_timer_ofdata_to_platdata(struct udevice *dev)
68 {
69 struct altera_timer_platdata *plat = dev_get_platdata(dev);
70
71 plat->regs = map_physmem(devfdt_get_addr(dev),
72 sizeof(struct altera_timer_regs),
73 MAP_NOCACHE);
74
75 return 0;
76 }
77
78 static const struct timer_ops altera_timer_ops = {
79 .get_count = altera_timer_get_count,
80 };
81
82 static const struct udevice_id altera_timer_ids[] = {
83 { .compatible = "altr,timer-1.0" },
84 {}
85 };
86
87 U_BOOT_DRIVER(altera_timer) = {
88 .name = "altera_timer",
89 .id = UCLASS_TIMER,
90 .of_match = altera_timer_ids,
91 .ofdata_to_platdata = altera_timer_ofdata_to_platdata,
92 .platdata_auto_alloc_size = sizeof(struct altera_timer_platdata),
93 .probe = altera_timer_probe,
94 .ops = &altera_timer_ops,
95 };
96