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486b973ee9
Add a simple driver which allows use of buttons attached to GPIOs. Reviewed-by: Simon Glass <sjg@chromium.org> Signed-off-by: Philippe Reynes <philippe.reynes@softathome.com>
112 lines
2.4 KiB
C
112 lines
2.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2020 Philippe Reynes <philippe.reynes@softathome.com>
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*/
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#include <common.h>
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#include <button.h>
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#include <dm.h>
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#include <dm/lists.h>
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#include <dm/uclass-internal.h>
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#include <log.h>
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#include <asm/gpio.h>
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struct button_gpio_priv {
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struct gpio_desc gpio;
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};
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static enum button_state_t button_gpio_get_state(struct udevice *dev)
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{
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struct button_gpio_priv *priv = dev_get_priv(dev);
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int ret;
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if (!dm_gpio_is_valid(&priv->gpio))
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return -EREMOTEIO;
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ret = dm_gpio_get_value(&priv->gpio);
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if (ret < 0)
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return ret;
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return ret ? BUTTON_ON : BUTTON_OFF;
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}
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static int button_gpio_probe(struct udevice *dev)
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{
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struct button_uc_plat *uc_plat = dev_get_uclass_platdata(dev);
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struct button_gpio_priv *priv = dev_get_priv(dev);
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int ret;
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/* Ignore the top-level button node */
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if (!uc_plat->label)
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return 0;
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ret = gpio_request_by_name(dev, "gpios", 0, &priv->gpio, GPIOD_IS_IN);
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if (ret)
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return ret;
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return 0;
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}
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static int button_gpio_remove(struct udevice *dev)
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{
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/*
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* The GPIO driver may have already been removed. We will need to
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* address this more generally.
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*/
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if (!IS_ENABLED(CONFIG_SANDBOX)) {
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struct button_gpio_priv *priv = dev_get_priv(dev);
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if (dm_gpio_is_valid(&priv->gpio))
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dm_gpio_free(dev, &priv->gpio);
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}
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return 0;
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}
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static int button_gpio_bind(struct udevice *parent)
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{
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struct udevice *dev;
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ofnode node;
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int ret;
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dev_for_each_subnode(node, parent) {
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struct button_uc_plat *uc_plat;
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const char *label;
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label = ofnode_read_string(node, "label");
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if (!label) {
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debug("%s: node %s has no label\n", __func__,
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ofnode_get_name(node));
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return -EINVAL;
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}
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ret = device_bind_driver_to_node(parent, "button_gpio",
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ofnode_get_name(node),
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node, &dev);
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if (ret)
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return ret;
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uc_plat = dev_get_uclass_platdata(dev);
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uc_plat->label = label;
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}
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return 0;
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}
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static const struct button_ops button_gpio_ops = {
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.get_state = button_gpio_get_state,
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};
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static const struct udevice_id button_gpio_ids[] = {
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{ .compatible = "gpio-keys" },
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{ .compatible = "gpio-keys-polled" },
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{ }
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};
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U_BOOT_DRIVER(button_gpio) = {
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.name = "button_gpio",
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.id = UCLASS_BUTTON,
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.of_match = button_gpio_ids,
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.ops = &button_gpio_ops,
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.priv_auto_alloc_size = sizeof(struct button_gpio_priv),
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.bind = button_gpio_bind,
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.probe = button_gpio_probe,
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.remove = button_gpio_remove,
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};
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