linux/drivers/input/keyboard/gpio_keys_polled.c
Hans de Goede 6f29d3b277 Input: gpio_keys_polled - add support for abs/rel axis
This changAdd support for EV_ABS / EV_REL events to the gpio-keys-polled driver.


The driver already allows specifying what type of events (key / rel / abs)
a button generates when pressed, but for rel / abs axis we also need to
specify which value this specific gpio represents.

One use case is digital joysticks / direction-pads which are hooked up to
gpio, in this case we've left and right buttons which we want to map to
EV_ABS, ABS_X and we want generate events for left with a value of -1 and
for right with a value of +1 (and similar for up / down and ABS_Y).

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2015-10-14 17:15:04 -07:00

382 lines
9.7 KiB
C

/*
* Driver for buttons on GPIO lines not capable of generating interrupts
*
* Copyright (C) 2007-2010 Gabor Juhos <juhosg@openwrt.org>
* Copyright (C) 2010 Nuno Goncalves <nunojpg@gmail.com>
*
* This file was based on: /drivers/input/misc/cobalt_btns.c
* Copyright (C) 2007 Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
*
* also was based on: /drivers/input/keyboard/gpio_keys.c
* Copyright 2005 Phil Blundell
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/input-polldev.h>
#include <linux/ioport.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/gpio_keys.h>
#include <linux/property.h>
#define DRV_NAME "gpio-keys-polled"
struct gpio_keys_button_data {
int last_state;
int count;
int threshold;
int can_sleep;
};
struct gpio_keys_polled_dev {
struct input_polled_dev *poll_dev;
struct device *dev;
const struct gpio_keys_platform_data *pdata;
unsigned long rel_axis_seen[BITS_TO_LONGS(REL_CNT)];
unsigned long abs_axis_seen[BITS_TO_LONGS(ABS_CNT)];
struct gpio_keys_button_data data[0];
};
static void gpio_keys_button_event(struct input_polled_dev *dev,
struct gpio_keys_button *button,
int state)
{
struct gpio_keys_polled_dev *bdev = dev->private;
struct input_dev *input = dev->input;
unsigned int type = button->type ?: EV_KEY;
if (type == EV_REL) {
if (state) {
input_event(input, type, button->code, button->value);
__set_bit(button->code, bdev->rel_axis_seen);
}
} else if (type == EV_ABS) {
if (state) {
input_event(input, type, button->code, button->value);
__set_bit(button->code, bdev->abs_axis_seen);
}
} else {
input_event(input, type, button->code, state);
input_sync(input);
}
}
static void gpio_keys_polled_check_state(struct input_polled_dev *dev,
struct gpio_keys_button *button,
struct gpio_keys_button_data *bdata)
{
int state;
if (bdata->can_sleep)
state = !!gpiod_get_value_cansleep(button->gpiod);
else
state = !!gpiod_get_value(button->gpiod);
gpio_keys_button_event(dev, button, state);
if (state != bdata->last_state) {
bdata->count = 0;
bdata->last_state = state;
}
}
static void gpio_keys_polled_poll(struct input_polled_dev *dev)
{
struct gpio_keys_polled_dev *bdev = dev->private;
const struct gpio_keys_platform_data *pdata = bdev->pdata;
struct input_dev *input = dev->input;
int i;
memset(bdev->rel_axis_seen, 0, sizeof(bdev->rel_axis_seen));
memset(bdev->abs_axis_seen, 0, sizeof(bdev->abs_axis_seen));
for (i = 0; i < pdata->nbuttons; i++) {
struct gpio_keys_button_data *bdata = &bdev->data[i];
if (bdata->count < bdata->threshold) {
bdata->count++;
gpio_keys_button_event(dev, &pdata->buttons[i],
bdata->last_state);
} else {
gpio_keys_polled_check_state(dev, &pdata->buttons[i],
bdata);
}
}
for_each_set_bit(i, input->relbit, REL_CNT) {
if (!test_bit(i, bdev->rel_axis_seen))
input_event(input, EV_REL, i, 0);
}
for_each_set_bit(i, input->absbit, ABS_CNT) {
if (!test_bit(i, bdev->abs_axis_seen))
input_event(input, EV_ABS, i, 0);
}
input_sync(input);
}
static void gpio_keys_polled_open(struct input_polled_dev *dev)
{
struct gpio_keys_polled_dev *bdev = dev->private;
const struct gpio_keys_platform_data *pdata = bdev->pdata;
if (pdata->enable)
pdata->enable(bdev->dev);
}
static void gpio_keys_polled_close(struct input_polled_dev *dev)
{
struct gpio_keys_polled_dev *bdev = dev->private;
const struct gpio_keys_platform_data *pdata = bdev->pdata;
if (pdata->disable)
pdata->disable(bdev->dev);
}
static struct gpio_keys_platform_data *gpio_keys_polled_get_devtree_pdata(struct device *dev)
{
struct gpio_keys_platform_data *pdata;
struct gpio_keys_button *button;
struct fwnode_handle *child;
int error;
int nbuttons;
nbuttons = device_get_child_node_count(dev);
if (nbuttons == 0)
return NULL;
pdata = devm_kzalloc(dev, sizeof(*pdata) + nbuttons * sizeof(*button),
GFP_KERNEL);
if (!pdata)
return ERR_PTR(-ENOMEM);
pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
pdata->rep = device_property_present(dev, "autorepeat");
device_property_read_u32(dev, "poll-interval", &pdata->poll_interval);
device_for_each_child_node(dev, child) {
struct gpio_desc *desc;
desc = devm_get_gpiod_from_child(dev, NULL, child);
if (IS_ERR(desc)) {
error = PTR_ERR(desc);
if (error != -EPROBE_DEFER)
dev_err(dev,
"Failed to get gpio flags, error: %d\n",
error);
fwnode_handle_put(child);
return ERR_PTR(error);
}
button = &pdata->buttons[pdata->nbuttons++];
button->gpiod = desc;
if (fwnode_property_read_u32(child, "linux,code", &button->code)) {
dev_err(dev, "Button without keycode: %d\n",
pdata->nbuttons - 1);
fwnode_handle_put(child);
return ERR_PTR(-EINVAL);
}
fwnode_property_read_string(child, "label", &button->desc);
if (fwnode_property_read_u32(child, "linux,input-type",
&button->type))
button->type = EV_KEY;
if (fwnode_property_read_u32(child, "linux,input-value",
(u32 *)&button->value))
button->value = 1;
button->wakeup =
fwnode_property_read_bool(child, "wakeup-source") ||
/* legacy name */
fwnode_property_read_bool(child, "gpio-key,wakeup");
if (fwnode_property_read_u32(child, "debounce-interval",
&button->debounce_interval))
button->debounce_interval = 5;
}
if (pdata->nbuttons == 0)
return ERR_PTR(-EINVAL);
return pdata;
}
static void gpio_keys_polled_set_abs_params(struct input_dev *input,
const struct gpio_keys_platform_data *pdata, unsigned int code)
{
int i, min = 0, max = 0;
for (i = 0; i < pdata->nbuttons; i++) {
struct gpio_keys_button *button = &pdata->buttons[i];
if (button->type != EV_ABS || button->code != code)
continue;
if (button->value < min)
min = button->value;
if (button->value > max)
max = button->value;
}
input_set_abs_params(input, code, min, max, 0, 0);
}
static const struct of_device_id gpio_keys_polled_of_match[] = {
{ .compatible = "gpio-keys-polled", },
{ },
};
MODULE_DEVICE_TABLE(of, gpio_keys_polled_of_match);
static int gpio_keys_polled_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
struct gpio_keys_polled_dev *bdev;
struct input_polled_dev *poll_dev;
struct input_dev *input;
size_t size;
int error;
int i;
if (!pdata) {
pdata = gpio_keys_polled_get_devtree_pdata(dev);
if (IS_ERR(pdata))
return PTR_ERR(pdata);
if (!pdata) {
dev_err(dev, "missing platform data\n");
return -EINVAL;
}
}
if (!pdata->poll_interval) {
dev_err(dev, "missing poll_interval value\n");
return -EINVAL;
}
size = sizeof(struct gpio_keys_polled_dev) +
pdata->nbuttons * sizeof(struct gpio_keys_button_data);
bdev = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
if (!bdev) {
dev_err(dev, "no memory for private data\n");
return -ENOMEM;
}
poll_dev = devm_input_allocate_polled_device(&pdev->dev);
if (!poll_dev) {
dev_err(dev, "no memory for polled device\n");
return -ENOMEM;
}
poll_dev->private = bdev;
poll_dev->poll = gpio_keys_polled_poll;
poll_dev->poll_interval = pdata->poll_interval;
poll_dev->open = gpio_keys_polled_open;
poll_dev->close = gpio_keys_polled_close;
input = poll_dev->input;
input->name = pdev->name;
input->phys = DRV_NAME"/input0";
input->id.bustype = BUS_HOST;
input->id.vendor = 0x0001;
input->id.product = 0x0001;
input->id.version = 0x0100;
__set_bit(EV_KEY, input->evbit);
if (pdata->rep)
__set_bit(EV_REP, input->evbit);
for (i = 0; i < pdata->nbuttons; i++) {
struct gpio_keys_button *button = &pdata->buttons[i];
struct gpio_keys_button_data *bdata = &bdev->data[i];
unsigned int type = button->type ?: EV_KEY;
if (button->wakeup) {
dev_err(dev, DRV_NAME " does not support wakeup\n");
return -EINVAL;
}
/*
* Legacy GPIO number so request the GPIO here and
* convert it to descriptor.
*/
if (!button->gpiod && gpio_is_valid(button->gpio)) {
unsigned flags = GPIOF_IN;
if (button->active_low)
flags |= GPIOF_ACTIVE_LOW;
error = devm_gpio_request_one(&pdev->dev, button->gpio,
flags, button->desc ? : DRV_NAME);
if (error) {
dev_err(dev, "unable to claim gpio %u, err=%d\n",
button->gpio, error);
return error;
}
button->gpiod = gpio_to_desc(button->gpio);
}
if (IS_ERR(button->gpiod))
return PTR_ERR(button->gpiod);
bdata->can_sleep = gpiod_cansleep(button->gpiod);
bdata->last_state = -1;
bdata->threshold = DIV_ROUND_UP(button->debounce_interval,
pdata->poll_interval);
input_set_capability(input, type, button->code);
if (type == EV_ABS)
gpio_keys_polled_set_abs_params(input, pdata,
button->code);
}
bdev->poll_dev = poll_dev;
bdev->dev = dev;
bdev->pdata = pdata;
platform_set_drvdata(pdev, bdev);
error = input_register_polled_device(poll_dev);
if (error) {
dev_err(dev, "unable to register polled device, err=%d\n",
error);
return error;
}
/* report initial state of the buttons */
for (i = 0; i < pdata->nbuttons; i++)
gpio_keys_polled_check_state(poll_dev, &pdata->buttons[i],
&bdev->data[i]);
input_sync(input);
return 0;
}
static struct platform_driver gpio_keys_polled_driver = {
.probe = gpio_keys_polled_probe,
.driver = {
.name = DRV_NAME,
.of_match_table = gpio_keys_polled_of_match,
},
};
module_platform_driver(gpio_keys_polled_driver);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
MODULE_DESCRIPTION("Polled GPIO Buttons driver");
MODULE_ALIAS("platform:" DRV_NAME);