1 // SPDX-License-Identifier: GPL-2.0+
3 * (C) Copyright 2000-2002
4 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
6 * (C) Copyright 2004, Psyent Corporation <www.psyent.com>
7 * Scott McNutt <smcnutt@psyent.com>
15 #include <linux/bitops.h>
17 /* control register */
18 #define ALTERA_TIMER_CONT BIT(1) /* Continuous mode */
19 #define ALTERA_TIMER_START BIT(2) /* Start timer */
20 #define ALTERA_TIMER_STOP BIT(3) /* Stop timer */
22 struct altera_timer_regs {
23 u32 status; /* Timer status reg */
24 u32 control; /* Timer control reg */
25 u32 periodl; /* Timeout period low */
26 u32 periodh; /* Timeout period high */
27 u32 snapl; /* Snapshot low */
28 u32 snaph; /* Snapshot high */
31 struct altera_timer_platdata {
32 struct altera_timer_regs *regs;
35 static u64 altera_timer_get_count(struct udevice *dev)
37 struct altera_timer_platdata *plat = dev->plat;
38 struct altera_timer_regs *const regs = plat->regs;
42 writel(0x0, ®s->snapl);
44 /* Read timer value */
45 val = readl(®s->snapl) & 0xffff;
46 val |= (readl(®s->snaph) & 0xffff) << 16;
47 return timer_conv_64(~val);
50 static int altera_timer_probe(struct udevice *dev)
52 struct altera_timer_platdata *plat = dev->plat;
53 struct altera_timer_regs *const regs = plat->regs;
55 writel(0, ®s->status);
56 writel(0, ®s->control);
57 writel(ALTERA_TIMER_STOP, ®s->control);
59 writel(0xffff, ®s->periodl);
60 writel(0xffff, ®s->periodh);
61 writel(ALTERA_TIMER_CONT | ALTERA_TIMER_START, ®s->control);
66 static int altera_timer_ofdata_to_platdata(struct udevice *dev)
68 struct altera_timer_platdata *plat = dev_get_plat(dev);
70 plat->regs = map_physmem(dev_read_addr(dev),
71 sizeof(struct altera_timer_regs),
77 static const struct timer_ops altera_timer_ops = {
78 .get_count = altera_timer_get_count,
81 static const struct udevice_id altera_timer_ids[] = {
82 { .compatible = "altr,timer-1.0" },
86 U_BOOT_DRIVER(altera_timer) = {
87 .name = "altera_timer",
89 .of_match = altera_timer_ids,
90 .ofdata_to_platdata = altera_timer_ofdata_to_platdata,
91 .plat_auto = sizeof(struct altera_timer_platdata),
92 .probe = altera_timer_probe,
93 .ops = &altera_timer_ops,