u-boot/drivers/input/button_kbd.c
Dzmitry Sankouski e877996289 dm: input: add button_kbd driver
Bootmenu requires an input device with arrows and enter key.
A common smartphone luckily has power, volume up/down buttons,
which may be used for controlling bootmenu.
To use driver, add 'button-kbd' to stdin.

Signed-off-by: Dzmitry Sankouski <dsankouski@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2023-02-10 13:41:06 -05:00

126 lines
2.9 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2023 Dzmitry Sankouski <dsankouski@gmail.com>
*/
#include <stdlib.h>
#include <common.h>
#include <dm.h>
#include <fdtdec.h>
#include <input.h>
#include <keyboard.h>
#include <button.h>
#include <dm/device-internal.h>
#include <log.h>
#include <asm/io.h>
#include <asm/gpio.h>
#include <linux/delay.h>
#include <linux/input.h>
/**
* struct button_kbd_priv - driver private data
*
* @input: input configuration
* @button_size: number of buttons found
* @old_state: a pointer to old button states array. Used to determine button state change.
*/
struct button_kbd_priv {
struct input_config *input;
u32 button_size;
u32 *old_state;
};
static int button_kbd_start(struct udevice *dev)
{
struct button_kbd_priv *priv = dev_get_priv(dev);
int i = 0;
struct udevice *button_gpio_devp;
uclass_foreach_dev_probe(UCLASS_BUTTON, button_gpio_devp) {
struct button_uc_plat *uc_plat = dev_get_uclass_plat(button_gpio_devp);
/* Ignore the top-level button node */
if (!uc_plat->label)
continue;
debug("Found button %s #%d - %s, probing...\n",
uc_plat->label, i, button_gpio_devp->name);
i++;
}
priv->button_size = i;
priv->old_state = calloc(i, sizeof(int));
return 0;
}
int button_read_keys(struct input_config *input)
{
struct button_kbd_priv *priv = dev_get_priv(input->dev);
struct udevice *button_gpio_devp;
struct uclass *uc;
int i = 0;
u32 code, state, state_changed = 0;
uclass_id_foreach_dev(UCLASS_BUTTON, button_gpio_devp, uc) {
struct button_uc_plat *uc_plat = dev_get_uclass_plat(button_gpio_devp);
/* Ignore the top-level button node */
if (!uc_plat->label)
continue;
code = button_get_code(button_gpio_devp);
if (!code)
continue;
state = button_get_state(button_gpio_devp);
state_changed = state != priv->old_state[i];
if (state_changed) {
debug("%s: %d\n", uc_plat->label, code);
priv->old_state[i] = state;
input_add_keycode(input, code, state);
}
i++;
}
return 0;
}
static const struct keyboard_ops button_kbd_ops = {
.start = button_kbd_start,
};
static int button_kbd_probe(struct udevice *dev)
{
struct button_kbd_priv *priv = dev_get_priv(dev);
struct keyboard_priv *uc_priv = dev_get_uclass_priv(dev);
struct stdio_dev *sdev = &uc_priv->sdev;
struct input_config *input = &uc_priv->input;
int ret = 0;
input_init(input, false);
input_add_tables(input, false);
/* Register the device. */
priv->input = input;
input->dev = dev;
input->read_keys = button_read_keys;
strcpy(sdev->name, "button-kbd");
ret = input_stdio_register(sdev);
if (ret) {
debug("%s: input_stdio_register() failed\n", __func__);
return ret;
}
return 0;
}
static const struct udevice_id button_kbd_ids[] = {
{ .compatible = "button-kbd" },
{ }
};
U_BOOT_DRIVER(button_kbd) = {
.name = "button_kbd",
.id = UCLASS_KEYBOARD,
.of_match = button_kbd_ids,
.ops = &button_kbd_ops,
.priv_auto = sizeof(struct button_kbd_priv),
.probe = button_kbd_probe,
};