linux/drivers/input/misc/max8925_onkey.c
Dmitry Torokhov 104a5f3cad Input: max8925_onkey - avoid accessing input device too early
Input device must be allocated (but not necessarily registered) before
requesting IRQs, otherwise there is a chance that IRQ handler fires and
tries to reference not yet allocated input device.

Also it makes sense to store relative IRQ numbers in max8925_onkey_info
structure as they are needed in suspend/resume which we expect to be
called more often than probe and remove.

Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2012-03-06 11:03:30 -08:00

205 lines
5.3 KiB
C

/**
* MAX8925 ONKEY driver
*
* Copyright (C) 2009 Marvell International Ltd.
* Haojian Zhuang <haojian.zhuang@marvell.com>
*
* This file is subject to the terms and conditions of the GNU General
* Public License. See the file "COPYING" in the main directory of this
* archive for more details.
*
* 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/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/i2c.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/mfd/max8925.h>
#include <linux/slab.h>
#define SW_INPUT (1 << 7) /* 0/1 -- up/down */
#define HARDRESET_EN (1 << 7)
#define PWREN_EN (1 << 7)
struct max8925_onkey_info {
struct input_dev *idev;
struct i2c_client *i2c;
struct device *dev;
unsigned int irq[2];
};
/*
* MAX8925 gives us an interrupt when ONKEY is pressed or released.
* max8925_set_bits() operates I2C bus and may sleep. So implement
* it in thread IRQ handler.
*/
static irqreturn_t max8925_onkey_handler(int irq, void *data)
{
struct max8925_onkey_info *info = data;
int state;
state = max8925_reg_read(info->i2c, MAX8925_ON_OFF_STATUS);
input_report_key(info->idev, KEY_POWER, state & SW_INPUT);
input_sync(info->idev);
dev_dbg(info->dev, "onkey state:%d\n", state);
/* Enable hardreset to halt if system isn't shutdown on time */
max8925_set_bits(info->i2c, MAX8925_SYSENSEL,
HARDRESET_EN, HARDRESET_EN);
return IRQ_HANDLED;
}
static int __devinit max8925_onkey_probe(struct platform_device *pdev)
{
struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
struct max8925_onkey_info *info;
struct input_dev *input;
int irq[2], error;
irq[0] = platform_get_irq(pdev, 0);
if (irq[0] < 0) {
dev_err(&pdev->dev, "No IRQ resource!\n");
return -EINVAL;
}
irq[1] = platform_get_irq(pdev, 1);
if (irq[1] < 0) {
dev_err(&pdev->dev, "No IRQ resource!\n");
return -EINVAL;
}
info = kzalloc(sizeof(struct max8925_onkey_info), GFP_KERNEL);
input = input_allocate_device();
if (!info || !input) {
error = -ENOMEM;
goto err_free_mem;
}
info->idev = input;
info->i2c = chip->i2c;
info->dev = &pdev->dev;
info->irq[0] = irq[0];
info->irq[1] = irq[1];
input->name = "max8925_on";
input->phys = "max8925_on/input0";
input->id.bustype = BUS_I2C;
input->dev.parent = &pdev->dev;
input_set_capability(input, EV_KEY, KEY_POWER);
irq[0] += chip->irq_base;
irq[1] += chip->irq_base;
error = request_threaded_irq(irq[0], NULL, max8925_onkey_handler,
IRQF_ONESHOT, "onkey-down", info);
if (error < 0) {
dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
irq[0], error);
goto err_free_mem;
}
error = request_threaded_irq(irq[1], NULL, max8925_onkey_handler,
IRQF_ONESHOT, "onkey-up", info);
if (error < 0) {
dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
irq[1], error);
goto err_free_irq0;
}
error = input_register_device(info->idev);
if (error) {
dev_err(chip->dev, "Can't register input device: %d\n", error);
goto err_free_irq1;
}
platform_set_drvdata(pdev, info);
device_init_wakeup(&pdev->dev, 1);
return 0;
err_free_irq1:
free_irq(irq[1], info);
err_free_irq0:
free_irq(irq[0], info);
err_free_mem:
input_free_device(input);
kfree(info);
return error;
}
static int __devexit max8925_onkey_remove(struct platform_device *pdev)
{
struct max8925_onkey_info *info = platform_get_drvdata(pdev);
struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
free_irq(info->irq[0] + chip->irq_base, info);
free_irq(info->irq[1] + chip->irq_base, info);
input_unregister_device(info->idev);
kfree(info);
platform_set_drvdata(pdev, NULL);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int max8925_onkey_suspend(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct max8925_onkey_info *info = platform_get_drvdata(pdev);
struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
if (device_may_wakeup(dev)) {
chip->wakeup_flag |= 1 << info->irq[0];
chip->wakeup_flag |= 1 << info->irq[1];
}
return 0;
}
static int max8925_onkey_resume(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct max8925_onkey_info *info = platform_get_drvdata(pdev);
struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
if (device_may_wakeup(dev)) {
chip->wakeup_flag &= ~(1 << info->irq[0]);
chip->wakeup_flag &= ~(1 << info->irq[1]);
}
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(max8925_onkey_pm_ops, max8925_onkey_suspend, max8925_onkey_resume);
static struct platform_driver max8925_onkey_driver = {
.driver = {
.name = "max8925-onkey",
.owner = THIS_MODULE,
.pm = &max8925_onkey_pm_ops,
},
.probe = max8925_onkey_probe,
.remove = __devexit_p(max8925_onkey_remove),
};
module_platform_driver(max8925_onkey_driver);
MODULE_DESCRIPTION("Maxim MAX8925 ONKEY driver");
MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
MODULE_LICENSE("GPL");