/*
* Texas Instruments' Palmas Power Button Input Driver
*
* Copyright (C) 2012-2014 Texas Instruments Incorporated - http://www.ti.com/
* Girish S Ghongdemath
* Nishanth Menon
*
* 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.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/init.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/mfd/palmas.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#define PALMAS_LPK_TIME_MASK 0x0c
#define PALMAS_PWRON_DEBOUNCE_MASK 0x03
#define PALMAS_PWR_KEY_Q_TIME_MS 20
/**
* struct palmas_pwron - Palmas power on data
* @palmas: pointer to palmas device
* @input_dev: pointer to input device
* @input_work: work for detecting release of key
* @irq: irq that we are hooked on to
*/
struct palmas_pwron {
struct palmas *palmas;
struct input_dev *input_dev;
struct delayed_work input_work;
int irq;
};
/**
* struct palmas_pwron_config - configuration of palmas power on
* @long_press_time_val: value for long press h/w shutdown event
* @pwron_debounce_val: value for debounce of power button
*/
struct palmas_pwron_config {
u8 long_press_time_val;
u8 pwron_debounce_val;
};
/**
* palmas_power_button_work() - Detects the button release event
* @work: work item to detect button release
*/
static void palmas_power_button_work(struct work_struct *work)
{
struct palmas_pwron *pwron = container_of(work,
struct palmas_pwron,
input_work.work);
struct input_dev *input_dev = pwron->input_dev;
unsigned int reg;
int error;
error = palmas_read(pwron->palmas, PALMAS_INTERRUPT_BASE,
PALMAS_INT1_LINE_STATE, ®);
if (error) {
dev_err(input_dev->dev.parent,
"Cannot read palmas PWRON status: %d\n", error);
} else if (reg & BIT(1)) {
/* The button is released, report event. */
input_report_key(input_dev, KEY_POWER, 0);
input_sync(input_dev);
} else {
/* The button is still depressed, keep checking. */
schedule_delayed_work(&pwron->input_work,
msecs_to_jiffies(PALMAS_PWR_KEY_Q_TIME_MS));
}
}
/**
* pwron_irq() - button press isr
* @irq: irq
* @palmas_pwron: pwron struct
*
* Return: IRQ_HANDLED
*/
static irqreturn_t pwron_irq(int irq, void *palmas_pwron)
{
struct palmas_pwron *pwron = palmas_pwron;
struct input_dev *input_dev = pwron->input_dev;
input_report_key(input_dev, KEY_POWER, 1);
pm_wakeup_event(input_dev->dev.parent, 0);
input_sync(input_dev);
mod_delayed_work(system_wq, &pwron->input_work,
msecs_to_jiffies(PALMAS_PWR_KEY_Q_TIME_MS));
return IRQ_HANDLED;
}
/**
* palmas_pwron_params_ofinit() - device tree parameter parser
* @dev: palmas button device
* @config: configuration params that this fills up
*/
static void palmas_pwron_params_ofinit(struct device *dev,
struct palmas_pwron_config *config)
{
struct device_node *np;
u32 val;
int i, error;
u8 lpk_times[] = { 6, 8, 10, 12 };
int pwr_on_deb_ms[] = { 15, 100, 500, 1000 };
memset(config, 0, sizeof(*config));
/* Default config parameters */
config->long_press_time_val = ARRAY_SIZE(lpk_times) - 1;
np = dev->of_node;
if (!np)
return;
error = of_property_read_u32(np, "ti,palmas-long-press-seconds", &val);
if (!error) {
for (i = 0; i < ARRAY_SIZE(lpk_times); i++) {
if (val <= lpk_times[i]) {
config->long_press_time_val = i;
break;
}
}
}
error = of_property_read_u32(np,
"ti,palmas-pwron-debounce-milli-seconds",
&val);
if (!error) {
for (i = 0; i < ARRAY_SIZE(pwr_on_deb_ms); i++) {
if (val <= pwr_on_deb_ms[i]) {
config->pwron_debounce_val = i;
break;
}
}
}
dev_info(dev, "h/w controlled shutdown duration=%d seconds\n",
lpk_times[config->long_press_time_val]);
}
/**
* palmas_pwron_probe() - probe
* @pdev: platform device for the button
*
* Return: 0 for successful probe else appropriate error
*/
static int palmas_pwron_probe(struct platform_device *pdev)
{
struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
struct device *dev = &pdev->dev;
struct input_dev *input_dev;
struct palmas_pwron *pwron;
struct palmas_pwron_config config;
int val;
int error;
palmas_pwron_params_ofinit(dev, &config);
pwron = kzalloc(sizeof(*pwron), GFP_KERNEL);
if (!pwron)
return -ENOMEM;
input_dev = input_allocate_device();
if (!input_dev) {
dev_err(dev, "Can't allocate power button\n");
error = -ENOMEM;
goto err_free_mem;
}
input_dev->name = "palmas_pwron";
input_dev->phys = "palmas_pwron/input0";
input_dev->dev.parent = dev;
input_set_capability(input_dev, EV_KEY, KEY_POWER);
/*
* Setup default hardware shutdown option (long key press)
* and debounce.
*/
val = config.long_press_time_val << __ffs(PALMAS_LPK_TIME_MASK);
val |= config.pwron_debounce_val << __ffs(PALMAS_PWRON_DEBOUNCE_MASK);
error = palmas_update_bits(palmas, PALMAS_PMU_CONTROL_BASE,
PALMAS_LONG_PRESS_KEY,
PALMAS_LPK_TIME_MASK |
PALMAS_PWRON_DEBOUNCE_MASK,
val);
if (error) {
dev_err(dev, "LONG_PRESS_KEY_UPDATE failed: %d\n", error);
goto err_free_input;
}
pwron->palmas = palmas;
pwron->input_dev = input_dev;
INIT_DELAYED_WORK(&pwron->input_work, palmas_power_button_work);
pwron->irq = platform_get_irq(pdev, 0);
error = request_threaded_irq(pwron->irq, NULL, pwron_irq,
IRQF_TRIGGER_HIGH |
IRQF_TRIGGER_LOW |
IRQF_ONESHOT,
dev_name(dev), pwron);
if (error) {
dev_err(dev, "Can't get IRQ for pwron: %d\n", error);
goto err_free_input;
}
error = input_register_device(input_dev);
if (error) {
dev_err(dev, "Can't register power button: %d\n", error);
goto err_free_irq;
}
platform_set_drvdata(pdev, pwron);
device_init_wakeup(dev, true);
return 0;
err_free_irq:
cancel_delayed_work_sync(&pwron->input_work);
free_irq(pwron->irq, pwron);
err_free_input:
input_free_device(input_dev);
err_free_mem:
kfree(pwron);
return error;
}
/**
* palmas_pwron_remove() - Cleanup on removal
* @pdev: platform device for the button
*
* Return: 0
*/
static int palmas_pwron_remove(struct platform_device *pdev)
{
struct palmas_pwron *pwron = platform_get_drvdata(pdev);
free_irq(pwron->irq, pwron);
cancel_delayed_work_sync(&pwron->input_work);
input_unregister_device(pwron->input_dev);
kfree(pwron);
return 0;
}
/**
* palmas_pwron_suspend() - suspend handler
* @dev: power button device
*
* Cancel all pending work items for the power button, setup irq for wakeup
*
* Return: 0
*/
static int __maybe_unused palmas_pwron_suspend(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct palmas_pwron *pwron = platform_get_drvdata(pdev);
cancel_delayed_work_sync(&pwron->input_work);
if (device_may_wakeup(dev))
enable_irq_wake(pwron->irq);
return 0;
}
/**
* palmas_pwron_resume() - resume handler
* @dev: power button device
*
* Just disable the wakeup capability of irq here.
*
* Return: 0
*/
static int __maybe_unused palmas_pwron_resume(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct palmas_pwron *pwron = platform_get_drvdata(pdev);
if (device_may_wakeup(dev))
disable_irq_wake(pwron->irq);
return 0;
}
static SIMPLE_DEV_PM_OPS(palmas_pwron_pm,
palmas_pwron_suspend, palmas_pwron_resume);
#ifdef CONFIG_OF
static const struct of_device_id of_palmas_pwr_match[] = {
{ .compatible = "ti,palmas-pwrbutton" },
{ },
};
MODULE_DEVICE_TABLE(of, of_palmas_pwr_match);
#endif
static struct platform_driver palmas_pwron_driver = {
.probe = palmas_pwron_probe,
.remove = palmas_pwron_remove,
.driver = {
.name = "palmas_pwrbutton",
.of_match_table = of_match_ptr(of_palmas_pwr_match),
.pm = &palmas_pwron_pm,
},
};
module_platform_driver(palmas_pwron_driver);
MODULE_ALIAS("platform:palmas-pwrbutton");
MODULE_DESCRIPTION("Palmas Power Button");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Texas Instruments Inc.");