summaryrefslogtreecommitdiff
path: root/drivers/watchdog/sbsa_gwdt.c
blob: 2eae431ba6c13c872e9c7744cfe7203dfd47309a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
// SPDX-License-Identifier: GPL-2.0+
/*
 * Watchdog driver for SBSA
 *
 * Copyright 2020 NXP
 */

#include <asm/io.h>
#include <common.h>
#include <dm/device.h>
#include <dm/fdtaddr.h>
#include <dm/read.h>
#include <linux/bitops.h>
#include <linux/err.h>
#include <watchdog.h>
#include <wdt.h>

DECLARE_GLOBAL_DATA_PTR;

/* SBSA Generic Watchdog register definitions */
/* refresh frame */
#define SBSA_GWDT_WRR		0x000

/* control frame */
#define SBSA_GWDT_WCS		0x000
#define SBSA_GWDT_WOR		0x008
#define SBSA_GWDT_WCV		0x010

/* refresh/control frame */
#define SBSA_GWDT_W_IIDR	0xfcc
#define SBSA_GWDT_IDR		0xfd0

/* Watchdog Control and Status Register */
#define SBSA_GWDT_WCS_EN	BIT(0)
#define SBSA_GWDT_WCS_WS0	BIT(1)
#define SBSA_GWDT_WCS_WS1	BIT(2)

struct sbsa_gwdt_priv {
	void __iomem *reg_refresh;
	void __iomem *reg_control;
};

static int sbsa_gwdt_reset(struct udevice *dev)
{
	struct sbsa_gwdt_priv *priv = dev_get_priv(dev);

	writel(0, priv->reg_refresh + SBSA_GWDT_WRR);

	return 0;
}

static int sbsa_gwdt_start(struct udevice *dev, u64 timeout, ulong flags)
{
	struct sbsa_gwdt_priv *priv = dev_get_priv(dev);
	u32 clk;

	/*
	 * it work in the single stage mode in u-boot,
	 * The first signal (WS0) is ignored,
	 * the timeout is (WOR * 2), so the WOR should be configured
	 * to half value of timeout.
	 */
	clk = get_tbclk();
	writel(clk / 2 * timeout,
	       priv->reg_control + SBSA_GWDT_WOR);

	/* writing WCS will cause an explicit watchdog refresh */
	writel(SBSA_GWDT_WCS_EN, priv->reg_control + SBSA_GWDT_WCS);

	return 0;
}

static int sbsa_gwdt_stop(struct udevice *dev)
{
	struct sbsa_gwdt_priv *priv = dev_get_priv(dev);

	writel(0, priv->reg_control + SBSA_GWDT_WCS);

	return 0;
}

static int sbsa_gwdt_expire_now(struct udevice *dev, ulong flags)
{
	sbsa_gwdt_start(dev, 0, flags);

	return 0;
}

static int sbsa_gwdt_probe(struct udevice *dev)
{
	debug("%s: Probing wdt%u (sbsa-gwdt)\n", __func__, dev->seq);

	return 0;
}

static int sbsa_gwdt_ofdata_to_platdata(struct udevice *dev)
{
	struct sbsa_gwdt_priv *priv = dev_get_priv(dev);

	priv->reg_control = (void __iomem *)dev_read_addr_index(dev, 0);
	if (IS_ERR(priv->reg_control))
		return PTR_ERR(priv->reg_control);

	priv->reg_refresh = (void __iomem *)dev_read_addr_index(dev, 1);
	if (IS_ERR(priv->reg_refresh))
		return PTR_ERR(priv->reg_refresh);

	return 0;
}

static const struct wdt_ops sbsa_gwdt_ops = {
	.start = sbsa_gwdt_start,
	.reset = sbsa_gwdt_reset,
	.stop = sbsa_gwdt_stop,
	.expire_now = sbsa_gwdt_expire_now,
};

static const struct udevice_id sbsa_gwdt_ids[] = {
	{ .compatible = "arm,sbsa-gwdt" },
	{}
};

U_BOOT_DRIVER(sbsa_gwdt) = {
	.name = "sbsa_gwdt",
	.id = UCLASS_WDT,
	.of_match = sbsa_gwdt_ids,
	.probe = sbsa_gwdt_probe,
	.priv_auto_alloc_size = sizeof(struct sbsa_gwdt_priv),
	.ofdata_to_platdata = sbsa_gwdt_ofdata_to_platdata,
	.ops = &sbsa_gwdt_ops,
};