要移植hall sensor的驅動，但手上沒有源碼，只能自己寫了，但能不能偷懶呢。在github上搜索一番，還真找到了，分享下。
dts參考配置
hall {
compatible = "hall-switch";
linux,gpio-int=<&ap_gpio 45 1>;
linux,wakeup;
vddio=<&vddcama>;
linux,max-uv=<2800>;
linux,min-uv=<2800>;
};
如果sensor的電源是常供的，去掉vddiio，找不到該電源，系統會默認拿一路dummy的電源。
源碼
/*
*
* Copyright (c) 2014-2015, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/input.h>
#include <linux/irq.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/pm.h>
#include <linux/module.h>
#include <linux/regulator/consumer.h>
#include <linux/of_gpio.h>
#include <linux/platform_device.h>
#define LID_DEV_NAME "hall_sensor"
#define HALL_INPUT "/dev/input/hall_dev"
struct hall_data {
int gpio; /* device use gpio number */
int irq; /* device request irq number */
int active_low; /* gpio active high or low for valid value */
bool wakeup; /* device can wakeup system or not */
struct input_dev *hall_dev;
struct regulator *vddio;
u32 min_uv; /* device allow minimum voltage */
u32 max_uv; /* device allow max voltage */
};
static irqreturn_t hall_interrupt_handler(int irq, void *dev)
{
int value;
struct hall_data *data = dev;
value = (gpio_get_value_cansleep(data->gpio) ? 1 : 0) ^
data->active_low;
if (value) {
input_report_switch(data->hall_dev, SW_LID, 0);
dev_dbg(&data->hall_dev->dev, "far\n");
} else {
input_report_switch(data->hall_dev, SW_LID, 1);
dev_dbg(&data->hall_dev->dev, "near\n");
}
input_sync(data->hall_dev);
return IRQ_HANDLED;
}
static int hall_input_init(struct platform_device *pdev,
struct hall_data *data)
{
int err = -1;
data->hall_dev = devm_input_allocate_device(&pdev->dev);
if (!data->hall_dev) {
dev_err(&data->hall_dev->dev,
"input device allocation failed\n");
return -EINVAL;
}
data->hall_dev->name = LID_DEV_NAME;
data->hall_dev->phys = HALL_INPUT;
__set_bit(EV_SW, data->hall_dev->evbit);
__set_bit(SW_LID, data->hall_dev->swbit);
err = input_register_device(data->hall_dev);
if (err < 0) {
dev_err(&data->hall_dev->dev,
"unable to register input device %s\n",
LID_DEV_NAME);
return err;
}
return 0;
}
static int hall_config_regulator(struct platform_device *dev, bool on)
{
struct hall_data *data = dev_get_drvdata(&dev->dev);
int rc = 0;
if (on) {
data->vddio = devm_regulator_get(&dev->dev, "vddio");
if (IS_ERR(data->vddio)) {
rc = PTR_ERR(data->vddio);
dev_err(&dev->dev, "Regulator vddio get failed rc=%d\n",
rc);
data->vddio = NULL;
return rc;
}
if (regulator_count_voltages(data->vddio) > 0) {
rc = regulator_set_voltage(
data->vddio,
data->min_uv,
data->max_uv);
if (rc) {
dev_err(&dev->dev, "Regulator vddio Set voltage failed rc=%d\n",
rc);
goto deinit_vregs;
}
}
return rc;
} else {
goto deinit_vregs;
}
deinit_vregs:
if (regulator_count_voltages(data->vddio) > 0)
regulator_set_voltage(data->vddio, 0, data->max_uv);
return rc;
}
static int hall_set_regulator(struct platform_device *dev, bool on)
{
struct hall_data *data = dev_get_drvdata(&dev->dev);
int rc = 0;
if (on) {
if (!IS_ERR_OR_NULL(data->vddio)) {
rc = regulator_enable(data->vddio);
if (rc) {
dev_err(&dev->dev, "Enable regulator vddio failed rc=%d\n",
rc);
goto disable_regulator;
}
}
return rc;
} else {
if (!IS_ERR_OR_NULL(data->vddio)) {
rc = regulator_disable(data->vddio);
if (rc)
dev_err(&dev->dev, "Disable regulator vddio failed rc=%d\n",
rc);
}
return 0;
}
disable_regulator:
if (!IS_ERR_OR_NULL(data->vddio))
regulator_disable(data->vddio);
return rc;
}
#ifdef CONFIG_OF
static int hall_parse_dt(struct device *dev, struct hall_data *data)
{
unsigned int tmp;
u32 tempval;
int rc;
struct device_node *np = dev->of_node;
data->gpio = of_get_named_gpio_flags(dev->of_node,
"linux,gpio-int", 0, &tmp);
if (!gpio_is_valid(data->gpio)) {
dev_err(dev, "hall gpio is not valid\n");
return -EINVAL;
}
data->active_low = tmp & OF_GPIO_ACTIVE_LOW ? 0 : 1;
data->wakeup = of_property_read_bool(np, "linux,wakeup");
rc = of_property_read_u32(np, "linux,max-uv", &tempval);
if (rc) {
dev_err(dev, "unable to read max-uv\n");
return -EINVAL;
}
data->max_uv = tempval;
rc = of_property_read_u32(np, "linux,min-uv", &tempval);
if (rc) {
dev_err(dev, "unable to read min-uv\n");
return -EINVAL;
}
data->min_uv = tempval;
return 0;
}
#else
static int hall_parse_dt(struct device *dev, struct hall_data *data)
{
return -EINVAL;
}
#endif
static int hall_driver_probe(struct platform_device *dev)
{
struct hall_data *data;
int err = 0;
int irq_flags;
dev_dbg(&dev->dev, "hall_driver probe\n");
data = devm_kzalloc(&dev->dev, sizeof(struct hall_data), GFP_KERNEL);
if (data == NULL) {
err = -ENOMEM;
dev_err(&dev->dev,
"failed to allocate memory %d\n", err);
goto exit;
}
dev_set_drvdata(&dev->dev, data);
if (dev->dev.of_node) {
err = hall_parse_dt(&dev->dev, data);
if (err < 0) {
dev_err(&dev->dev, "Failed to parse device tree\n");
goto exit;
}
} else if (dev->dev.platform_data != NULL) {
memcpy(data, dev->dev.platform_data, sizeof(*data));
} else {
dev_err(&dev->dev, "No valid platform data.\n");
err = -ENODEV;
goto exit;
}
err = hall_input_init(dev, data);
if (err < 0) {
dev_err(&dev->dev, "input init failed\n");
goto exit;
}
if (!gpio_is_valid(data->gpio)) {
dev_err(&dev->dev, "gpio is not valid\n");
err = -EINVAL;
goto exit;
}
irq_flags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING
| IRQF_ONESHOT;
err = gpio_request_one(data->gpio, GPIOF_DIR_IN, "hall_sensor_irq");
if (err) {
dev_err(&dev->dev, "unable to request gpio %d\n", data->gpio);
goto exit;
}
data->irq = gpio_to_irq(data->gpio);
err = devm_request_threaded_irq(&dev->dev, data->irq, NULL,
hall_interrupt_handler,
irq_flags, "hall_sensor", data);
if (err < 0) {
dev_err(&dev->dev, "request irq failed : %d\n", data->irq);
goto free_gpio;
}
device_init_wakeup(&dev->dev, data->wakeup);
enable_irq_wake(data->irq);
err = hall_config_regulator(dev, true);
if (err < 0) {
dev_err(&dev->dev, "Configure power failed: %d\n", err);
goto free_irq;
}
err = hall_set_regulator(dev, true);
if (err < 0) {
dev_err(&dev->dev, "power on failed: %d\n", err);
goto err_regulator_init;
}
return 0;
err_regulator_init:
hall_config_regulator(dev, false);
free_irq:
disable_irq_wake(data->irq);
device_init_wakeup(&dev->dev, 0);
free_gpio:
gpio_free(data->gpio);
exit:
return err;
}
static int hall_driver_remove(struct platform_device *dev)
{
struct hall_data *data = dev_get_drvdata(&dev->dev);
disable_irq_wake(data->irq);
device_init_wakeup(&dev->dev, 0);
if (data->gpio)
gpio_free(data->gpio);
hall_set_regulator(dev, false);
hall_config_regulator(dev, false);
return 0;
}
static struct platform_device_id hall_id[] = {
{LID_DEV_NAME, 0 },
{ },
};
#ifdef CONFIG_OF
static struct of_device_id hall_match_table[] = {
{.compatible = "hall-switch", },
{ },
};
#endif
static struct platform_driver hall_driver = {
.driver = {
.name = LID_DEV_NAME,
.owner = THIS_MODULE,
.of_match_table = of_match_ptr(hall_match_table),
},
.probe = hall_driver_probe,
.remove = hall_driver_remove,
.id_table = hall_id,
};
static int __init hall_init(void)
{
return platform_driver_register(&hall_driver);
}
static void __exit hall_exit(void)
{
platform_driver_unregister(&hall_driver);
}
module_init(hall_init);
module_exit(hall_exit);
MODULE_DESCRIPTION("Hall sensor driver");
MODULE_LICENSE("GPL v2");
再看看Android framewock層對該按鍵的處理
// Called by window manager policy. Not exposed externally.
@Override
public int getLidState() {
int sw = mInputManager.getSwitchState(-1, InputDevice.SOURCE_ANY,
InputManagerService.SW_LID);
if (sw > 0) {
// Switch state: AKEY_STATE_DOWN or AKEY_STATE_VIRTUAL.
return LID_CLOSED;
} else if (sw == 0) {
// Switch state: AKEY_STATE_UP.
return LID_OPEN;
} else {
// Switch state: AKEY_STATE_UNKNOWN.
return LID_ABSENT;
}
}
// Ca
private void updateWakeGestureListenerLp() {
if (shouldEnableWakeGestureLp()) {
mWakeGestureListener.requestWakeUpTrigger();
} else {
mWakeGestureListener.cancelWakeUpTrigger();
}
}
private boolean shouldEnableWakeGestureLp() {
return mWakeGestureEnabledSetting && !mDefaultDisplayPolicy.isAwake()
&& (getLidBehavior() != LID_BEHAVIOR_SLEEP
|| mDefaultDisplayPolicy.getLidState() != LID_CLOSED)
&& mWakeGestureListener.isSupported();
}
public WakeGestureListener(Context context, Handler handler) {
mSensorManager = (SensorManager)context.getSystemService(Context.SENSOR_SERVICE);
mHandler = handler;
mSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_WAKE_GESTURE);
}
public abstract void onWakeUp();
public boolean isSupported() {
synchronized (mLock) {
return mSensor != null;
}
}
也就是支持TYPE_WAKE_GESTURE的手機，彙報SW_LID類型的值就能亮屏。TYPE_WAKE_GESTURE的值一般在廠商的hal層sensor驅動中配置。