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gerrit.devboardsforandroid.linaro.org / platform / external / u-boot / 1817c3824a08bbad7fd2fbae1a6e73be896e8e5e / . / drivers / watchdog / max6370_wdt.c
blob: 584a4ed468c3b07fc5e519f1653491d2d5d0fd0e [file] [log] [blame]
Pali Rohár0a095fc2022-05-02 18:41:07 +0200[diff] [blame]1// SPDX-License-Identifier: GPL-2.0+
2// (C) 2022 Pali Rohár <pali@kernel.org>
3
4#include <asm/io.h>
5#include <asm-generic/gpio.h>
6#include <dm.h>
7#include <linux/delay.h>
8#include <wdt.h>
9
10#define MAX6370_SET_MASK 0x7
11#define MAX6370_SET_1MS 0x0
12#define MAX6370_SET_10MS 0x1
13#define MAX6370_SET_30MS 0x2
14#define MAX6370_SET_DISABLE 0x3
15#define MAX6370_SET_100MS 0x4
16#define MAX6370_SET_1S 0x5
17#define MAX6370_SET_10S 0x6
18#define MAX6370_SET_60S 0x7
19
20#define MAX6370_WDI 0x8
21
22struct max6370_wdt {
23 void __iomem *reg;
24 struct gpio_desc gpio_wdi;
25};
26
27static int max6370_wdt_start(struct udevice *dev, u64 ms, ulong flags)
28{
29 struct max6370_wdt *wdt = dev_get_priv(dev);
30 u8 val;
31
32 val = readb(wdt->reg);
33 val &= ~MAX6370_SET_MASK;
34
35 if (ms <= 1)
36 val |= MAX6370_SET_1MS;
37 else if (ms <= 10)
38 val |= MAX6370_SET_10MS;
39 else if (ms <= 30)
40 val |= MAX6370_SET_30MS;
41 else if (ms <= 100)
42 val |= MAX6370_SET_100MS;
43 else if (ms <= 1000)
44 val |= MAX6370_SET_1S;
45 else if (ms <= 10000)
46 val |= MAX6370_SET_10S;
47 else
48 val |= MAX6370_SET_60S;
49
50 writeb(val, wdt->reg);
51
52 return 0;
53}
54
55static int max6370_wdt_stop(struct udevice *dev)
56{
57 struct max6370_wdt *wdt = dev_get_priv(dev);
58 u8 val;
59
60 val = readb(wdt->reg);
61 val &= ~MAX6370_SET_MASK;
62 val |= MAX6370_SET_DISABLE;
63 writeb(val, wdt->reg);
64
65 return 0;
66}
67
68static int max6370_wdt_reset(struct udevice *dev)
69{
70 struct max6370_wdt *wdt = dev_get_priv(dev);
71 u8 val;
72
73 if (dm_gpio_is_valid(&wdt->gpio_wdi)) {
74 dm_gpio_set_value(&wdt->gpio_wdi, 1);
Pali Rohárc5f5ee32022-09-27 12:19:19 +0200[diff] [blame]75 __udelay(1);
Pali Rohár0a095fc2022-05-02 18:41:07 +0200[diff] [blame]76 dm_gpio_set_value(&wdt->gpio_wdi, 0);
77 } else {
78 val = readb(wdt->reg);
79 writeb(val | MAX6370_WDI, wdt->reg);
80 writeb(val & ~MAX6370_WDI, wdt->reg);
81 }
82
83 return 0;
84}
85
86static int max6370_wdt_probe(struct udevice *dev)
87{
88 struct max6370_wdt *wdt = dev_get_priv(dev);
89
90 wdt->reg = dev_read_addr_ptr(dev);
91 if (!wdt->reg)
92 return -EINVAL;
93
94 /* WDI gpio is optional */
95 gpio_request_by_name(dev, "gpios", 0, &wdt->gpio_wdi, GPIOD_IS_OUT);
96
97 return 0;
98}
99
100static const struct wdt_ops max6370_wdt_ops = {
101 .start = max6370_wdt_start,
102 .stop = max6370_wdt_stop,
103 .reset = max6370_wdt_reset,
104};
105
106static const struct udevice_id max6370_wdt_ids[] = {
107 { .compatible = "maxim,max6370" },
108 {}
109};
110
111U_BOOT_DRIVER(max6370_wdt) = {
112 .name = "max6370_wdt",
113 .id = UCLASS_WDT,
114 .of_match = max6370_wdt_ids,
115 .probe = max6370_wdt_probe,
116 .priv_auto = sizeof(struct max6370_wdt),
117 .ops = &max6370_wdt_ops,
118};