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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2011 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
*/
#include <common.h>
#include <errno.h>
#include <init.h>
#include <clock.h>
#include <gpio_keys.h>
#include <poller.h>
#include <gpio.h>
#include <of_gpio.h>
#include <input/input.h>
struct gpio_key {
int code;
int gpio;
int active_low;
int previous_state;
int debounce_interval;
u64 debounce_start;
};
struct gpio_keys {
struct gpio_key *buttons;
int nbuttons;
struct poller_async poller;
struct input_device input;
struct device *dev;
};
static void gpio_key_poller(void *data)
{
struct gpio_keys *gk = data;
struct gpio_key *gb;
int i, val;
for (i = 0; i < gk->nbuttons; i++) {
gb = &gk->buttons[i];
if (gpio_slice_acquired(gb->gpio))
goto out;
}
for (i = 0; i < gk->nbuttons; i++) {
gb = &gk->buttons[i];
val = gpio_get_value(gb->gpio);
if (!is_timeout(gb->debounce_start, gb->debounce_interval * MSECOND))
continue;
if (val != gb->previous_state) {
int pressed = val != gb->active_low;
gb->debounce_start = get_time_ns();
input_report_key_event(&gk->input, gb->code, pressed);
dev_dbg(gk->dev, "%s gpio(%d) as %d\n",
pressed ? "pressed" : "released", gb->gpio, gb->code);
gb->previous_state = val;
}
}
out:
poller_call_async(&gk->poller, 10 * MSECOND, gpio_key_poller, gk);
}
static int gpio_keys_probe_pdata(struct gpio_keys *gk, struct device *dev)
{
struct gpio_keys_platform_data *pdata;
int i;
pdata = dev->platform_data;
if (!pdata) {
/* small (so we copy it) but critical! */
dev_err(dev, "missing platform_data\n");
return -ENODEV;
}
gk->buttons = xzalloc(pdata->nbuttons * sizeof(*gk->buttons));
gk->nbuttons = pdata->nbuttons;
for (i = 0; i < gk->nbuttons; i++) {
gk->buttons[i].gpio = pdata->buttons[i].gpio;
gk->buttons[i].code = pdata->buttons[i].code;
gk->buttons[i].active_low = pdata->buttons[i].active_low;
gk->buttons[i].debounce_interval = 20;
}
return 0;
}
static int gpio_keys_probe_dt(struct gpio_keys *gk, struct device *dev)
{
struct device_node *npkey, *np = dev->of_node;
int i = 0, ret;
if (!IS_ENABLED(CONFIG_OFDEVICE) || !IS_ENABLED(CONFIG_OF_GPIO))
return -ENODEV;
gk->nbuttons = of_get_child_count(np);
gk->buttons = xzalloc(gk->nbuttons * sizeof(*gk->buttons));
for_each_child_of_node(np, npkey) {
enum of_gpio_flags gpioflags;
uint32_t keycode;
gk->buttons[i].gpio = of_get_named_gpio_flags(npkey, "gpios", 0, &gpioflags);
if (gk->buttons[i].gpio < 0)
return gk->buttons[i].gpio;
if (gpioflags & OF_GPIO_ACTIVE_LOW)
gk->buttons[i].active_low = 1;
ret = of_property_read_u32(npkey, "linux,code", &keycode);
if (ret)
return ret;
gk->buttons[i].debounce_interval = 20;
of_property_read_u32(npkey, "debounce-interval",
&gk->buttons[i].debounce_interval);
gk->buttons[i].code = keycode;
i++;
}
return 0;
}
static int __init gpio_keys_probe(struct device *dev)
{
int ret, i, gpio;
struct gpio_keys *gk;
gk = xzalloc(sizeof(*gk));
gk->dev = dev;
if (dev->of_node)
ret = gpio_keys_probe_dt(gk, dev);
else
ret = gpio_keys_probe_pdata(gk, dev);
if (ret)
return ret;
for (i = 0; i < gk->nbuttons; i++) {
gpio = gk->buttons[i].gpio;
ret = gpio_request(gpio, "gpio_keys");
if (ret) {
pr_err("gpio_keys: (%d) can not be requested\n", gpio);
return ret;
}
gpio_direction_input(gpio);
gk->buttons[i].previous_state = gk->buttons[i].active_low;
}
ret = input_device_register(&gk->input);
if (ret)
return ret;
ret = poller_async_register(&gk->poller, dev_name(dev));
if (ret)
return ret;
poller_call_async(&gk->poller, 10 * MSECOND, gpio_key_poller, gk);
return 0;
}
static struct of_device_id key_gpio_of_ids[] = {
{ .compatible = "gpio-keys", },
{ }
};
MODULE_DEVICE_TABLE(of, key_gpio_of_ids);
static struct driver gpio_keys_driver = {
.name = "gpio_keys",
.probe = gpio_keys_probe,
.of_compatible = DRV_OF_COMPAT(key_gpio_of_ids),
};
device_platform_driver(gpio_keys_driver);
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