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/*
* Power button driver for Medfield.
*
* Copyright (C) 2010 Intel Corp
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* 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.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/input.h>
#include <linux/mfd/intel_msic.h>
#define DRIVER_NAME "msic_power_btn"
#define MSIC_PB_LEVEL (1 << 3) /* 1 - release, 0 - press */
/*
* MSIC document ti_datasheet defines the 1st bit reg 0x21 is used to mask
* power button interrupt
*/
#define MSIC_PWRBTNM (1 << 0)
static irqreturn_t mfld_pb_isr(int irq, void *dev_id)
{
struct input_dev *input = dev_id;
int ret;
u8 pbstat;
ret = intel_msic_reg_read(INTEL_MSIC_PBSTATUS, &pbstat);
dev_dbg(input->dev.parent, "PB_INT status= %d\n", pbstat);
if (ret < 0) {
dev_err(input->dev.parent, "Read error %d while reading"
" MSIC_PB_STATUS\n", ret);
} else {
input_event(input, EV_KEY, KEY_POWER,
!(pbstat & MSIC_PB_LEVEL));
input_sync(input);
}
return IRQ_HANDLED;
}
static int mfld_pb_probe(struct platform_device *pdev)
{
struct input_dev *input;
int irq = platform_get_irq(pdev, 0);
int error;
if (irq < 0)
return -EINVAL;
input = input_allocate_device();
if (!input) {
dev_err(&pdev->dev, "Input device allocation error\n");
return -ENOMEM;
}
input->name = pdev->name;
input->phys = "power-button/input0";
input->id.bustype = BUS_HOST;
input->dev.parent = &pdev->dev;
input_set_capability(input, EV_KEY, KEY_POWER);
error = request_threaded_irq(irq, NULL, mfld_pb_isr, IRQF_NO_SUSPEND,
DRIVER_NAME, input);
if (error) {
dev_err(&pdev->dev, "Unable to request irq %d for mfld power"
"button\n", irq);
goto err_free_input;
}
error = input_register_device(input);
if (error) {
dev_err(&pdev->dev, "Unable to register input dev, error "
"%d\n", error);
goto err_free_irq;
}
platform_set_drvdata(pdev, input);
/*
* SCU firmware might send power button interrupts to IA core before
* kernel boots and doesn't get EOI from IA core. The first bit of
* MSIC reg 0x21 is kept masked, and SCU firmware doesn't send new
* power interrupt to Android kernel. Unmask the bit when probing
* power button in kernel.
* There is a very narrow race between irq handler and power button
* initialization. The race happens rarely. So we needn't worry
* about it.
*/
error = intel_msic_reg_update(INTEL_MSIC_IRQLVL1MSK, 0, MSIC_PWRBTNM);
if (error) {
dev_err(&pdev->dev, "Unable to clear power button interrupt, "
"error: %d\n", error);
goto err_free_irq;
}
return 0;
err_free_irq:
free_irq(irq, input);
err_free_input:
input_free_device(input);
return error;
}
static int mfld_pb_remove(struct platform_device *pdev)
{
struct input_dev *input = platform_get_drvdata(pdev);
int irq = platform_get_irq(pdev, 0);
free_irq(irq, input);
input_unregister_device(input);
platform_set_drvdata(pdev, NULL);
return 0;
}
static struct platform_driver mfld_pb_driver = {
.driver = {
.name = DRIVER_NAME,
.owner = THIS_MODULE,
},
.probe = mfld_pb_probe,
.remove = mfld_pb_remove,
};
module_platform_driver(mfld_pb_driver);
MODULE_AUTHOR("Hong Liu <hong.liu@intel.com>");
MODULE_DESCRIPTION("Intel Medfield Power Button Driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:" DRIVER_NAME);
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