1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Toggles a GPIO pin to power down a device
4 *
5 * Created using the Linux driver as reference, which
6 * has been written by:
7 *
8 * Jamie Lentin <jm@lentin.co.uk>
9 * Andrew Lunn <andrew@lunn.ch>
10 *
11 * Copyright (C) 2012 Jamie Lentin
12 */
13
14 #include <common.h>
15 #include <dm.h>
16 #include <errno.h>
17 #include <log.h>
18 #include <sysreset.h>
19
20 #include <asm/gpio.h>
21 #include <linux/delay.h>
22
23 struct poweroff_gpio_info {
24 struct gpio_desc gpio;
25 u32 active_delay_ms;
26 u32 inactive_delay_ms;
27 u32 timeout_ms;
28 };
29
poweroff_gpio_request(struct udevice * dev,enum sysreset_t type)30 static int poweroff_gpio_request(struct udevice *dev, enum sysreset_t type)
31 {
32 struct poweroff_gpio_info *priv = dev_get_priv(dev);
33 int r;
34
35 if (type != SYSRESET_POWER_OFF)
36 return -ENOSYS;
37
38 debug("GPIO poweroff\n");
39
40 /* drive it active, also inactive->active edge */
41 r = dm_gpio_set_value(&priv->gpio, 1);
42 if (r < 0)
43 return r;
44 mdelay(priv->active_delay_ms);
45
46 /* drive inactive, also active->inactive edge */
47 r = dm_gpio_set_value(&priv->gpio, 0);
48 if (r < 0)
49 return r;
50 mdelay(priv->inactive_delay_ms);
51
52 /* drive it active, also inactive->active edge */
53 r = dm_gpio_set_value(&priv->gpio, 1);
54 if (r < 0)
55 return r;
56
57 /* give it some time */
58 mdelay(priv->timeout_ms);
59
60 return -EINPROGRESS;
61 }
62
poweroff_gpio_probe(struct udevice * dev)63 static int poweroff_gpio_probe(struct udevice *dev)
64 {
65 struct poweroff_gpio_info *priv = dev_get_priv(dev);
66 int flags;
67
68 flags = dev_read_bool(dev, "input") ? GPIOD_IS_IN : GPIOD_IS_OUT;
69 priv->active_delay_ms = dev_read_u32_default(dev, "active-delay-ms", 100);
70 priv->inactive_delay_ms = dev_read_u32_default(dev, "inactive-delay-ms", 100);
71 priv->timeout_ms = dev_read_u32_default(dev, "timeout-ms", 3000);
72
73 return gpio_request_by_name(dev, "gpios", 0, &priv->gpio, flags);
74 }
75
76 static struct sysreset_ops poweroff_gpio_ops = {
77 .request = poweroff_gpio_request,
78 };
79
80 static const struct udevice_id poweroff_gpio_ids[] = {
81 { .compatible = "gpio-poweroff", },
82 {},
83 };
84
85 U_BOOT_DRIVER(poweroff_gpio) = {
86 .name = "poweroff-gpio",
87 .id = UCLASS_SYSRESET,
88 .ops = &poweroff_gpio_ops,
89 .probe = poweroff_gpio_probe,
90 .priv_auto = sizeof(struct poweroff_gpio_info),
91 .of_match = poweroff_gpio_ids,
92 };
93