1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright (C) 2017 ��lvaro Fern��ndez Rojas <noltari@gmail.com>
4 *
5 * Derived from linux/drivers/watchdog/bcm63xx_wdt.c:
6 *	Copyright (C) 2007 Miguel Gaio <miguel.gaio@efixo.com>
7 *	Copyright (C) 2008 Florian Fainelli <florian@openwrt.org>
8 */
9
10#include <dm.h>
11#include <log.h>
12#include <wdt.h>
13#include <clk.h>
14#include <asm/io.h>
15
16/* WDT Value register */
17#define WDT_VAL_REG		0x0
18#define WDT_VAL_MIN		0x00000002
19#define WDT_VAL_MAX		0xfffffffe
20
21/* WDT Control register */
22#define WDT_CTL_REG		0x4
23#define WDT_CTL_START1_MASK	0x0000ff00
24#define WDT_CTL_START2_MASK	0x000000ff
25#define WDT_CTL_STOP1_MASK	0x0000ee00
26#define WDT_CTL_STOP2_MASK	0x000000ee
27
28struct bcm6345_wdt_priv {
29	void __iomem *regs;
30	unsigned long clk_rate;
31};
32
33static int bcm6345_wdt_reset(struct udevice *dev)
34{
35	struct bcm6345_wdt_priv *priv = dev_get_priv(dev);
36
37	writel(WDT_CTL_START1_MASK, priv->regs + WDT_CTL_REG);
38	writel(WDT_CTL_START2_MASK, priv->regs + WDT_CTL_REG);
39
40	return 0;
41}
42
43static int bcm6345_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
44{
45	struct bcm6345_wdt_priv *priv = dev_get_priv(dev);
46	u32 val = priv->clk_rate / 1000 * timeout;
47
48	if (val < WDT_VAL_MIN) {
49		debug("watchdog won't fire with less than 2 ticks\n");
50		val = WDT_VAL_MIN;
51	} else if (val > WDT_VAL_MAX) {
52		debug("maximum watchdog timeout exceeded\n");
53		val = WDT_VAL_MAX;
54	}
55
56	writel(val, priv->regs + WDT_VAL_REG);
57
58	return bcm6345_wdt_reset(dev);
59}
60
61static int bcm6345_wdt_expire_now(struct udevice *dev, ulong flags)
62{
63	return bcm6345_wdt_start(dev, WDT_VAL_MIN, flags);
64}
65
66static int bcm6345_wdt_stop(struct udevice *dev)
67{
68	struct bcm6345_wdt_priv *priv = dev_get_priv(dev);
69
70	writel(WDT_CTL_STOP1_MASK, priv->regs + WDT_CTL_REG);
71	writel(WDT_CTL_STOP2_MASK, priv->regs + WDT_CTL_REG);
72
73	return 0;
74}
75
76static const struct wdt_ops bcm6345_wdt_ops = {
77	.expire_now = bcm6345_wdt_expire_now,
78	.reset = bcm6345_wdt_reset,
79	.start = bcm6345_wdt_start,
80	.stop = bcm6345_wdt_stop,
81};
82
83static const struct udevice_id bcm6345_wdt_ids[] = {
84	{ .compatible = "brcm,bcm6345-wdt" },
85	{ /* sentinel */ }
86};
87
88static int bcm6345_wdt_probe(struct udevice *dev)
89{
90	struct bcm6345_wdt_priv *priv = dev_get_priv(dev);
91	struct clk clk;
92	int ret;
93
94	priv->regs = dev_remap_addr(dev);
95	if (!priv->regs)
96		return -EINVAL;
97
98	ret = clk_get_by_index(dev, 0, &clk);
99	if (!ret)
100		priv->clk_rate = clk_get_rate(&clk);
101	else
102		return -EINVAL;
103
104	bcm6345_wdt_stop(dev);
105
106	return 0;
107}
108
109U_BOOT_DRIVER(wdt_bcm6345) = {
110	.name = "wdt_bcm6345",
111	.id = UCLASS_WDT,
112	.of_match = bcm6345_wdt_ids,
113	.ops = &bcm6345_wdt_ops,
114	.priv_auto	= sizeof(struct bcm6345_wdt_priv),
115	.probe = bcm6345_wdt_probe,
116};
117