1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2018 Xilinx, Inc. - Michal Simek
4 */
5
6 #include <common.h>
7 #include <dm.h>
8 #include <errno.h>
9 #include <log.h>
10 #include <sysreset.h>
11 #include <asm/gpio.h>
12
13 struct gpio_reboot_priv {
14 struct gpio_desc gpio;
15 };
16
gpio_reboot_request(struct udevice * dev,enum sysreset_t type)17 static int gpio_reboot_request(struct udevice *dev, enum sysreset_t type)
18 {
19 struct gpio_reboot_priv *priv = dev_get_priv(dev);
20 int ret;
21
22 /*
23 * When debug log is enabled please make sure that chars won't end up
24 * in output fifo. Or you can append udelay(); to get enough time
25 * to HW to emit output fifo.
26 */
27 debug("GPIO reset\n");
28
29 /* Writing 1 respects polarity (active high/low) based on gpio->flags */
30 ret = dm_gpio_set_value(&priv->gpio, 1);
31 if (ret < 0)
32 return ret;
33
34 return -EINPROGRESS;
35 }
36
37 static struct sysreset_ops gpio_reboot_ops = {
38 .request = gpio_reboot_request,
39 };
40
gpio_reboot_probe(struct udevice * dev)41 static int gpio_reboot_probe(struct udevice *dev)
42 {
43 struct gpio_reboot_priv *priv = dev_get_priv(dev);
44
45 /*
46 * Linux kernel DT binding contain others optional properties
47 * which are not supported now
48 */
49
50 return gpio_request_by_name(dev, "gpios", 0, &priv->gpio, GPIOD_IS_OUT);
51 }
52
53 static const struct udevice_id led_gpio_ids[] = {
54 { .compatible = "gpio-restart" },
55 { }
56 };
57
58 U_BOOT_DRIVER(gpio_reboot) = {
59 .id = UCLASS_SYSRESET,
60 .name = "gpio_restart",
61 .of_match = led_gpio_ids,
62 .ops = &gpio_reboot_ops,
63 .priv_auto = sizeof(struct gpio_reboot_priv),
64 .probe = gpio_reboot_probe,
65 };
66