// SPDX-License-Identifier: GPL-2.0+ /* * Toggles a GPIO pin to power down a device * * Created using the Linux driver as reference, which * has been written by: * * Jamie Lentin * Andrew Lunn * * Copyright (C) 2012 Jamie Lentin */ #include #include #include #include #include #include #include struct poweroff_gpio_info { struct gpio_desc gpio; u32 active_delay_ms; u32 inactive_delay_ms; u32 timeout_ms; }; static int poweroff_gpio_request(struct udevice *dev, enum sysreset_t type) { struct poweroff_gpio_info *priv = dev_get_priv(dev); int r; if (type != SYSRESET_POWER_OFF) return -EPROTONOSUPPORT; debug("GPIO poweroff\n"); /* drive it active, also inactive->active edge */ r = dm_gpio_set_value(&priv->gpio, 1); if (r < 0) return r; mdelay(priv->active_delay_ms); /* drive inactive, also active->inactive edge */ r = dm_gpio_set_value(&priv->gpio, 0); if (r < 0) return r; mdelay(priv->inactive_delay_ms); /* drive it active, also inactive->active edge */ r = dm_gpio_set_value(&priv->gpio, 1); if (r < 0) return r; /* give it some time */ mdelay(priv->timeout_ms); return -EINPROGRESS; } static int poweroff_gpio_probe(struct udevice *dev) { struct poweroff_gpio_info *priv = dev_get_priv(dev); int flags; flags = dev_read_bool(dev, "input") ? GPIOD_IS_IN : GPIOD_IS_OUT; priv->active_delay_ms = dev_read_u32_default(dev, "active-delay-ms", 100); priv->inactive_delay_ms = dev_read_u32_default(dev, "inactive-delay-ms", 100); priv->timeout_ms = dev_read_u32_default(dev, "timeout-ms", 3000); return gpio_request_by_name(dev, "gpios", 0, &priv->gpio, flags); } static struct sysreset_ops poweroff_gpio_ops = { .request = poweroff_gpio_request, }; static const struct udevice_id poweroff_gpio_ids[] = { { .compatible = "gpio-poweroff", }, {}, }; U_BOOT_DRIVER(poweroff_gpio) = { .name = "poweroff-gpio", .id = UCLASS_SYSRESET, .ops = &poweroff_gpio_ops, .probe = poweroff_gpio_probe, .priv_auto = sizeof(struct poweroff_gpio_info), .of_match = poweroff_gpio_ids, };