1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (C) 2017 Álvaro Fernández 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 <common.h>
11 #include <dm.h>
12 #include <wdt.h>
13 #include <asm/io.h>
14
15 /* WDT Value register */
16 #define WDT_VAL_REG 0x0
17 #define WDT_VAL_MIN 0x00000002
18 #define WDT_VAL_MAX 0xfffffffe
19
20 /* WDT Control register */
21 #define WDT_CTL_REG 0x4
22 #define WDT_CTL_START1_MASK 0x0000ff00
23 #define WDT_CTL_START2_MASK 0x000000ff
24 #define WDT_CTL_STOP1_MASK 0x0000ee00
25 #define WDT_CTL_STOP2_MASK 0x000000ee
26
27 struct bcm6345_wdt_priv {
28 void __iomem *regs;
29 };
30
bcm6345_wdt_reset(struct udevice * dev)31 static int bcm6345_wdt_reset(struct udevice *dev)
32 {
33 struct bcm6345_wdt_priv *priv = dev_get_priv(dev);
34
35 writel(WDT_CTL_START1_MASK, priv->regs + WDT_CTL_REG);
36 writel(WDT_CTL_START2_MASK, priv->regs + WDT_CTL_REG);
37
38 return 0;
39 }
40
bcm6345_wdt_start(struct udevice * dev,u64 timeout,ulong flags)41 static int bcm6345_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
42 {
43 struct bcm6345_wdt_priv *priv = dev_get_priv(dev);
44
45 if (timeout < WDT_VAL_MIN) {
46 debug("watchdog won't fire with less than 2 ticks\n");
47 timeout = WDT_VAL_MIN;
48 } else if (timeout > WDT_VAL_MAX) {
49 debug("maximum watchdog timeout exceeded\n");
50 timeout = WDT_VAL_MAX;
51 }
52
53 writel(timeout, priv->regs + WDT_VAL_REG);
54
55 return bcm6345_wdt_reset(dev);
56 }
57
bcm6345_wdt_expire_now(struct udevice * dev,ulong flags)58 static int bcm6345_wdt_expire_now(struct udevice *dev, ulong flags)
59 {
60 return bcm6345_wdt_start(dev, WDT_VAL_MIN, flags);
61 }
62
bcm6345_wdt_stop(struct udevice * dev)63 static int bcm6345_wdt_stop(struct udevice *dev)
64 {
65 struct bcm6345_wdt_priv *priv = dev_get_priv(dev);
66
67 writel(WDT_CTL_STOP1_MASK, priv->regs + WDT_CTL_REG);
68 writel(WDT_CTL_STOP2_MASK, priv->regs + WDT_CTL_REG);
69
70 return 0;
71 }
72
73 static const struct wdt_ops bcm6345_wdt_ops = {
74 .expire_now = bcm6345_wdt_expire_now,
75 .reset = bcm6345_wdt_reset,
76 .start = bcm6345_wdt_start,
77 .stop = bcm6345_wdt_stop,
78 };
79
80 static const struct udevice_id bcm6345_wdt_ids[] = {
81 { .compatible = "brcm,bcm6345-wdt" },
82 { /* sentinel */ }
83 };
84
bcm6345_wdt_probe(struct udevice * dev)85 static int bcm6345_wdt_probe(struct udevice *dev)
86 {
87 struct bcm6345_wdt_priv *priv = dev_get_priv(dev);
88
89 priv->regs = dev_remap_addr(dev);
90 if (!priv->regs)
91 return -EINVAL;
92
93 bcm6345_wdt_stop(dev);
94
95 return 0;
96 }
97
98 U_BOOT_DRIVER(wdt_bcm6345) = {
99 .name = "wdt_bcm6345",
100 .id = UCLASS_WDT,
101 .of_match = bcm6345_wdt_ids,
102 .ops = &bcm6345_wdt_ops,
103 .priv_auto_alloc_size = sizeof(struct bcm6345_wdt_priv),
104 .probe = bcm6345_wdt_probe,
105 };
106